Acid-fast bacilli in fine needle aspiration smears from tuberculous lymph nodes. Where to look for them

OBJECTIVE: To analyze where acid-fast bacilli (AFB) are most often seen in smears prepared from tuberculous lymph nodes. STUDY DESIGN: Patients referred for fine needle aspiration cytology for evaluation of lymphadenopathy between March 1994 and June 1998 were analyzed. Only those cases clinically and therapeutically proven to be tuberculous were included in the study. RESULTS: Of 783 cases analyzed, 213 (27.2%) were tuberculous. Aspirates obtained were of three types: blood-mixed particles, caseous material and pus. Five cytologic pictures were seen: epithelioid cell granulomas alone or with coexistent necrosis, AFB or both, and necrosis with AFB. AFB were most often seen in purulent aspirates, followed by caseous and least often in blood-mixed particles. Granulomas were most often seen when the aspirate was blood-mixed particles, followed by caseous and, least often, pus. CONCLUSION: AFB detection should be carried out on all suspected tuberculous patients. The relationship between the presence of granuloma and of AFB is inverse. The chance of finding AFB is highest in patients presenting with a cold abscess and yielding pus on aspiration followed by patients who yield caseous material on aspiration.     

Fine needle aspiration cytology in the diagnosis of tuberculous mastitis

OBJECTIVE: To study the relationship between granulomas in the breast and tuberculous mastitis. STUDY DESIGN: Retrospective analysis of 22 breast aspirates that showed epithelioid cell granulomas. The aspirates were reviewed and the cytomorphologic findings summarized. RESULTS: Aspiration cytology revealed epithelioid cell granulomas along with giant cells, necrosis and inflammatory cell infiltrate. Overall acid-fast bacillus (AFB) positivity was 22.7%. AFB positivity was greater in the presence of necrosis when epithelioid cells were absent. CONCLUSION: In a country like India, the diagnosis of granulomatous mastitis must be made with caution, even in the absence of AFB. Only after a sufficient trial of antituberculosis treatment has been given and the patient fails to respond should an alternative diagnosis be suggested.     

Role of modified bleach method in staining of acid-fast bacilli in lymph node aspirates

OBJECTIVE: To correlate acid-fast bacilli (AFB) positivity with cytomorphologic patterns of tuberculous lymphadenitis and evaluate bleach concentration method in diagnosing lymph node tuberculosis compared to Ziehl-Neelsen (ZN) method. STUDY DESIGN: One hundred cases of tuberculous lymphadenitis diagnosed by fine needle aspiration cytology (FNAC) were analyzed and classified into 6 cytomorphologic patterns and correlated with bacillary load using routine and modified bleach methods of ZN staining. Smears were graded for AFB positivity. Sensitivity of routine ZN and modified bleach concentration was compared. RESULTS: The classic cytomorphologic pattern of tuberculosis showing epithelioid granulomas, Langerhans giant cells and caseous necrosis was seen in 23% of cases. Routine ZN staining detected AFB in 27% of cases and the modified bleach method in 72%. In 58 cases the modified bleach method had a higher grade of AFB positivity than the routine method. The modified bleach method did not miss any AFB positivity detected on routine ZN staining. CONCLUSION: The modified bleach method demonstrated AFB positivity in 72% of cases. AFB positivity grade was much higher than with routine ZN staining, making bacilli easily visible, with shorter screening time. The modified bleach method is inexpensive, easily performed and more sensitive and safe than routine ZN staining.     

Tuberculosis of the intercostal lymph nodes

OBJECTIVE: To describe tuberculosis of the intercostal lymph nodes and discuss its clinical and cytologic profile and pathogenesis. STUDY DESIGN: Fifteen cases from March 1994 to March 2000 were retrieved from our cytology records. Only clinically and therapeutically proven cases were included in the study. RESULTS: The ages of the patients ranged from 4 to 63 years. The male:female ratio was 2:1. The duration of disease at presentation ranged from one week to nine months. The lumps presented either in the parasternal region or between the midclavicular and posterior axillary lines. One case presented with an infrascapular lump. Most of the lumps were ill defined and cystic. Chest radiographs in all cases showed a soft tissue swelling without bony involvement. The aspirates were of two types, blood-mixed particles and necrotic material. Four cytologic pictures were seen: (1) epithelioid cell granulomas alone or (2) with necrosis or (3) with both necrosis and acid-fast bacilli (AFB), or (4) necrosis with AFB. AFB were detected in 53.3% of cases. CONCLUSION: If necrotic material is aspirated or if granulomatous inflammation is encountered in soft tissue swellings of the chest wall, particularly in the parasternal and axillary regions, the possibility of intercostal tuberculous lymphadenitis should be considered.     

Tuberculosis of the breast. A cytomorphologic study

OBJECTIVE: Extrapulmonary tuberculosis occurring in the breast is rare despite the fact that 1-2 billion people worldwide suffer from tuberculosis. The aim of this study was to examine the cytomorphology of breast tuberculosis (breast TB) and to review the literature. STUDY DESIGN: Old records from the Cytopathology Laboratory, All India Institute of Medical Sciences, were reviewed from January 1980 to December 1998. Cases of breast TB where a cytologic diagnosis was rendered or a histologic diagnosis with prior fine needle aspiration cytology (FNAC) was available were selected. These slides were reviewed for determining the cytologic findings. RESULTS: One hundred sixty cases of breast TB were included in the study. Six males and 154 females with a clinical suspicion of carcinoma had undergone FNA that was reported as TB. The majority of the patients (111) were in the reproductive age group, 21-40 years. Of the 160 cases, 118 (73.75%) had cytomorphology diagnostic of tuberculosis--epithelioid cell granulomas with caseous necrosis. Eleven of the remaining 42 cases were positive for acid-fast bacilli (AFB) on Ziehl-Neelsen (ZN) staining, while 31 cases were confirmed to be tubercular on histology. ZN staining was done in 44 cases, and AFB were demonstrated in only 38.6% of cases. CONCLUSION: Up to 73% of breast TB can be confidently diagnosed when both epithelioid cell granulomas and necrosis are present. Also, the possibility that a woman in the reproductive age group who presents with a palpable lump in the breast may have tuberculosis must be kept in mind, especially as the incidence of breast TB may increase in the future with the global spread of AIDS.     

Fine needle aspiration cytology of suspected tuberculous lymphadenitis

Fine needle aspiration cytology of suspected tuberculous lymphadenitis The aims of this cross-sectional study were to describe the distributional patterns of tuberculous lymphadenitis and to assess the correlation between fine needle aspiration cytology (FNAC) and the Ziehl Neelsen staining technique in diagnosing tuberculous lymphadenitis. Romanowsky's method (Wright's stain) for cytological diagnosis and Ziehl Neelsen (hot method) for the identification of acid-fast bacilli were utilized. Out of one hundred and twenty-eight consecutive patients attending the cytological diagnostic service of the Department of Pathology within Jimma University, 89 (69.6%) of the patients were younger than 30 years of age. The male to female ratio was 1.3 : 1. The cervical region was the most common site and involved 95 cases (74.2%), followed by the axillary and inguinal lymph node regions (20.3% and 4.3%, respectively). The Wright's-stained cytology smears were grouped into three categories: epithelioid granulomas without necrosis, epithelioid granulomas with caseous necrosis and necrosis without epithelioid granulomas. The Ziehl Neelsen stains were undertaken on separate slides: 20.0% of the cases showing epithelioid granulomas without necrosis, 61.9% of those with epithelioid granulomas with necrosis/abscesses and 69.7% of those with necrosis without granulomas were found to be positive for acid-fast bacilli. The overall positivity for the ZiehlNeelsen stained cases was 59.4%. It can therefore be concluded that FNAC is a reliable diagnostic tool in helping to avert the more invasive surgical procedures undertaken in the diagnosis of tuberculous adenitis. The ZiehlNeelsen stain for identification of acid-fast bacilli should be incorporated as an adjunct to increase the diagnostic accuracy of tuberculous lymphadenitis.     

Assessment of the N-PCR Assay in Diagnosis of Pleural Tuberculosis: Detection of M.tuberculosis in Pleural Fluid and Sputum Collected in Tandem

Background

The nonspecific clinical presentation and paucibacillary nature of tuberculous pleuritis remains a challenge for diagnosis. Diagnosis of tuberculous pleural effusion depends on the demonstration of the presence of tubercle bacilli in the sputum, pleural fluid, or pleural biopsy specimen, or demonstration of granuloma in pleura by histological examination. We examined the clinical utility of the diagnosis of pleural tuberculosis using the in house N-PCR assay, AFB smear microscopy and culture. Besides pleural fluid the inclusion of sputum in the efficacy of diagnosis of pleural tuberculosis was scrutinized.

Methodology/Principal Findings

Pleural fluid and sputum samples of 58 tuberculous and 42 non-tuberculous pleural effusion patients were processed for AFB smear microscopy, culture and the N-PCR assay. Mycobacteria were detected exclusively in tuberculous pleural effusion samples. None of the non-tuberculous pleural effusion samples were positive for mycobacteria. Comparative analysis showed that the N-PCR assay had the highest sensitivity. Inclusion of sputum along with pleural fluid increased N-PCR sensitivity from 51.7 to 70.6% (p<0.0001).This improved sensitivity was reflected in AFB smear microscopy and isolation by culture. The sensitivity enhanced on inclusion of sputum from 3.4 (p = 0.50) to 10.3% (p = 0.038) for AFB smear microscopy and for isolation of mycobacteria from 10.3(p = 0.03) to 22.4% (p = 0.0005). Thirteen isolates were obtained from 58 pleural tuberculosis patients. Eleven mycobacterial isolates were identified as M.tuberculosis and two as M.fortuitum and M.chelonae. Complete concordance was seen between the biochemical identification of isolates and the N-PCR identification of mycobacterial species prior to isolation.

Conclusions/Significance

To the best of our knowledge this is the first PCR based report on utility of sputum for diagnosis of pleural tuberculosis. The present study demonstrates that a combination of pleural fluid with sputum sample and N-PCR improved the diagnosis of pleural tuberculosis.     

Utility of papanicolaou stain-induced fluorescence in the cytodiagnosis of extrapulmonary tuberculosis

OBJECTIVE: To study the utility of Papanicolaou stain-induced fluorescence (PIF) in the detection of tubercle bacilli and to compare its diagnostic efficacy with that of the conventional Ziehl-Neelsen (ZN) method. STUDY DESIGN: This prospective study was carried out at a tertiary health care center, over a period of 2 years between January 2001 and December 2002. A total of 500 cases offine needle aspiration cytology from lymph nodes and other extrapulmonary sites were studied. Only cases that were clinically and cytologically suggestive of tuberculosis were included in the study. The smears were stained with ZN and Papanicolaou stain and examined under light and fluorescence microscopes, respectively for detection of acid-fast bacilli (AFB). Mycobacterial culture was used as the gold standard to compare the results. RESULTS: Cytologic smears were categorized into 4 distinct cytomorphologic patterns: epithelioid granulomas without caseous necrosis (101 cases), epithelioid granulomas with caseous necrosis (268 cases), caseation or acute inflammatory exudate only (114 cases), and occasional epithelioid cells without necrosis or giant cells (17 cases). The overall AFB positivity was 30.8% with the ZN method, while it was 40.6% with PIF. Moreover, PIF was more effective in detecting bacilli in group I lesions (18.8% vs. 6.9% with ZN method), in which the bacillary load is very low. CONCLUSION: PIF is superior to the conventional ZN method in detecting tubercle bacilli, particularly when the bacillary load is low. It is a relatively inexpensive and fast technique.     

Fine needle aspiration cytology in the diagnosis of sinuses and ulcers of the body surface (skin and tongue)

Both fine needle aspiration (FNA) and conventional scraping were used to obtain cytodiagnostic samples from ulcers and sinuses of the skin (18 cases) and tongue (3 cases). These included 14 cases of tuberculosis, 5 squamous-cell carcinomas and 2 cases of nonspecific infection. The FNA smears contained characteristic tuberculous granulomas or epithelioid cells in 10 of the 14 tuberculosis cases and ample diagnostic material in 4 of the 5 carcinoma cases; in contrast the scraping smears predominantly contained necrotic material on which a diagnosis was not possible. Of the 19 cases of tuberculosis and malignancy, 12 were diagnosed only by FNA, 6 were diagnosed by both methods and the FNA sample was negative while the scrape was positive in 1 case. Hence, the diagnosis was made in 18 of 19 by FNA cytology, but in only 7 of 19 cases by scraping cytology, strongly indicating the diagnostic superiority of the former in diagnosing many lesions of the body surface.     

Use of fine needle aspiration cytology in leprotic lesions: a report of 4 cases

BACKGROUND: Although a few studies have shown fine needle aspiration cytology (FNAC) to be a sensitive diagnostic tool in the detection of nerve involvement, its role as an initial diagnostic procedure in pure neuritic leprosy (PNL) and in the detection of skeletal lesions with unusual findings has not been documented before. CASES: Three patients who presented with thickened nerves and a fourth with biopsy-proven lepromatous leprosy with lesions in hand bones underwent FNAC. Of the 3 patients with nerve thickening, 2 had a clinical suspicion or diagnosis of neuritic leprosy, whereas in the third patient a clinical differential diagnosis of a soft tissue tumor or parasitic cyst was considered. FNAC in all 3 cases revealed epithelioid cell granulomas, Langhans giant cells and caseous necrosis. Fites and Ziehl-Neelsen stains were negative for acid-fast bacilli. Cytologic diagnosis of pure neuritic leprosy was made in all 3 cases and confirmed by histopathologic examination. FNAC of skeletal lesions from the fourth patient confirmed involvement of bone with unusual cytologic findings of epithelioid cell granulomas and giant cells along with a significant proportion of foamy macrophages and strong Fites stain positivity. CONCLUSION: FNAC is a simple, useful, minimally traumatic and routinely applicable procedure in the diagnosis of pure neuritic leprosy and leprous osteitis.     

Pulmonary epithelioid hemangioendothelioma: report of a case with fine needle aspiration biopsy

BACKGROUND: Pulmonary epithelioid hemangioendothelioma (PEH) is a rare, low grade, malignant vascular tumor that typically presents with multiple pulmonary nodules in young women. This report details the cytopathologic and pathologic findings in an unusual case presenting in an older male with a pleural effusion, dominant nodule and multiple bilateral infiltrates. CASE: A 62-year-old, male nonsmoker was referred due to increasing dyspnea. Chest radiography revealed a pleural effusion and nodular infiltrate in the right upper lobe of the bronchus. Thoracocentesis and thoracoscopy were performed, with a pleural drain inserted. Bronchoscopy revealed a right upper lobe bronchus occluded by a greyish, necrotic mass. Various cytopathologic sampling techniques, including fine needle aspiration biopsy, as well as traditional histopathologic biopsies were performed. Cytologic specimens showed loosely cohesive, epithelioid cells that were binucleated and multinucleated. Chromatin was granular, with scattered, small, multiple nucleoli with occasional, variably sized cytoplasmic vacuoles. The patient's condition deteriorated, and he died 3 weeks after admission. CONCLUSION: Pulmonary epithelioid hemangioendotheliomas are unusual neoplasms with a epithelioid, discohesive cellular appearance. It can mimic other, more commonly seen pulmonary neoplasms. Careful attention to cytomorphologic features and application of ancillary studies assist in making the diagnosis.     

Value of radiologically guided fine needle aspiration cytology (FNAC) in the diagnosis of spinal tuberculosis: a study of 29 cases

FNAC is a simple diagnostic tool for the initial evaluation of various deep seated pathological lesions. This study describes the applicability and practical aspects of the technique in establishing the diagnosis of spinal tuberculosis (TB) with the aid of radiographic guidance. The study was conducted in a major teaching hospital in Kuwait between the years 1985 and 1994. Twenty-nine patients (M:F = 18:11 and age range 8-72 years) with clinically and/or radiologically suspected spinal TB were seen in the Department of Cytology, Mubarak Al Kabeer Hospital. The patients were re-examined by either computed tomography (CT) scanning (n = 19) or fluoroscopy (n = 10) to localize the lesion for FNAC. FNAC smears were routinely stained with Papanicolaou and Diff Quik stains and one smear of each case was stained with Ziehl-Neelsen (Z-N) stain for acid-fast bacilli (AFB). Aspirated purulent material or syringe washings of dry aspirates were also submitted for microbiological cultures including AFB. Radiological and cytological findings were recorded in each case. Radiological findings included: bony rarefaction and destruction (93.1%), narrowed disc space (89.7%), soft tissue calcification (65.5%) and para-vertebral abscess formation (51.7%). Cytological findings included: epithelioid cell granulomas (89.7%), granular necrotic background (82.8%) and lymphocytic infiltration (75.9%). Smears were positive for AFB in 51.7% of cases. A positive AFB culture was obtained in 82.8% of cases, including all cases with positive AFB on smear by Z-N stain. Radiologically guided FNAC with AFB culture is a simple, reliable and practical approach to diagnosing spinal TB lesions. With a high diagnostic yield, it allows immediate initiation of specific treatment, helps to avoid invasive diagnostic procedures, and decreases hospitalization time.     

Fine needle aspiration cytology of tubercular epididymitis and epididymo-orchitis

OBJECTIVE: To study the role of fine needle aspiration cytology (FNAC) and ancillary studies in the diagnosis of tubercular epididymitis or epididymo-orchitis. STUDY DESIGN: Forty patients with tubercular epididymitis or epididymoorchitis diagnosed on FNAC underwent a detailed clinical workup, imaging and microbiologic studies before being started on antitubercular treatment (ATT). One patient underwent orchiectomy. RESULTS: Clinically, the disease presented in patients of all ages usually as a scrotal swelling or rarely as a scrotal sinus (3) or abscess (3) or as part of disseminated tuberculosis (2). Three patients gave a history of previous tuberculosis. Scrotal sonography confirmed the involvement of the epididymis, testis or spermatic cord in each case. FNAC was diagnostic in 27 aspirates (epithelioid cell granulomas with caseation) but nondiagnostic in the rest. Tubercular etiology was confirmed directly by detection of acid-fast bacilli (AFB) on FNA smears in 24 (60%) patients and urine samples in 11 and indirectly in 9 patients with negative AFB by using a combination of a positive Mantoux test (5 of 9), presence of caseating granulomas on FNA smears (7 of 9) and therapeutic response to ATT (9 of 9). CONCLUSION: FNA as a minimally invasive technique plays a prime role in the diagnosis of tubercular epididymitis and epididymoorchitis. It provides adequate material for cytologic and microbiologic examination and helps to avoid unnecesary orchiectomy.     

Thyroid tuberculosis – role of PCR in diagnosis of a rare entity

N. Gupta, K. Sharma, A. Barwad, M. Sharma, A. Rajwanshi, P. Dutta and A. Sharma
Thyroid tuberculosis – role of PCR in diagnosis of a rare entity Background: Tuberculosis is a rare cause of granulomatous thyroiditis, whose diagnosis may be difficult with routine cytopathology and staining for acid‐fast bacilli (AFB). Study design: Amongst 7962 cases of various thyroid lesions subjected to fine needle aspiration cytology (FNAC) over a period of 12 years, 34 cases (0.43%) were found to have cytological features of granulomatous inflammation with or without necrosis, which could be due to tuberculosis, granulomatous thyroiditis or other causes of granulomatous inflammation such as sarcoidosis or fungal infections. DNA was extracted from the material available on May‐Grünwald–Giemsa‐stained smears from the archival material. PCR for Mycobacterium tuberculosis was performed for insertion sequence IS6110. Results: The age of the patients ranged from 32 to 58 years (median 48 years); 24 were female and 10 male. FNAC from thyroid swellings showed epithelioid granulomas with giant cells and/or necrosis. Although acid‐fast bacilli were only seen in smears in two cases, 19/34 (55.9%) showed the presence of 123 bp DNA band under ultraviolet transillumination. Five control cases were negative. Conclusion: Our study of archival cytological material illustrates the importance of PCR as a potentially useful tool for the detection of M. tuberculosis DNA from FNAC of thyroid lesions, which could provide an alternative for rapid diagnosis of thyroid tuberculosis in AFB‐negative cases.     

Nucleic acid amplification of Mycobacterium tuberculosis complex DNA from archival fine needle aspiration smear scrapings vs. fresh fine needle aspirates of tuberculous lymphadenitis

OBJECTIVE: To assess the efficacy of the nucleic acid amplification (NAA) technique for Mycobacterium tuberculosis (MTB) complex from archival fine needle aspirate (FNA) smear scrapings of confirmed cases of extrapulmonary tuberculosis (EPTB) for a retrospective diagnosis of EPTB as compared to NAA from fresh FNA material from the same cases. STUDY DESIGN: Smear scrapings from 51 cases; 33 cases of tuberculous lymphadenitis (from patients who had undergone NAA 1 year before for MTB from fresh FNA material); 13 negative controls from nontuberculous, archival FNA smears; and 5 known acid-fast bacilli (AFB)-positive sputum smears, were subjected to NAA using the IS6110 primer sequence of M tuberculosis. Ziehl-Neelsen staining was done in all the smears. RESULTS: Of the 33 cases of tuberculous lymphadenitis, 15 (45.4%) were AFB positive and 18 (64.5%) AFB negative. MTB NAA was positive in 73.3% (11 of 15 AFB-positive cases) in the freshly aspirated material and was observed in 60% (9 of 15 AFB-positive cases) when done on DNA extracted from the archival smear scrapings of the same cases. Similarly, in the 18 AFB-negative cases, MTB NAA positivity was 72.2% (13 of 18) on fresh material and 44.4% (8 of 18) on archival smear scrapings from the same AFB-negative cases. Overall NAA positivity was 51.5% for archival smear scrapings as compared to 71% for fresh FNA of the same cases. CONCLUSION: Low NAA sensitivity of MTB DNA in archival material of known tuberculous cases limits the routine use of NAA based retrospective molecular diagnosis of MTB complex.     

Utility of repeat fine needle aspiration in acute suppurative lesions. Follow-up of 263 cases

OBJECTIVE: To determine the clinical value of repeat fine needle aspiration (FNA) as a follow-up strategy in the management of patients in India, clinically suspected of having tuberculosis (TB) but showing a cytologic picture of acute suppuration. STUDY DESIGN: Repeat aspirates from 263 patients presenting with lymph node or soft tissue masses were analyzed. The previous FNA of these cases had shown acute inflammatory exudate but no epithelioid granuloma or acid-fast bacilli (AFB). RESULTS: The repeat FNA helped to detect 55% additional cases of TB within a period of 8 weeks; 67% of them were diagnosed in the second and third weeks. Diagnostic yield rose to 59% after the third FNA. AFB were detected in 34 (13.3%) cases that showed a low bacterial load. In addition, nontubercular lesions, such as epidermal inclusion cyst (4), cysticercosis (3), sialadenitis (2) and metastatic carcinoma (8), were diagnosed. CONCLUSION: All cases showing acute suppuration without granulomas or AFB on the first FNA should be reevaluated by follow-up FNA and staining for AFB. This will enhance the diagnostic yield of tuberculosis in developing countries, where molecular diagnostics are too costly or unavailable. This procedure is cost effective as compared to biopsy and culture. In addition to tuberculosis, many unexpected nontubercular lesions may also be unmasked. Repeat FNA reduces sampling and screening errors, improves sensitivity and helps to study the evolution of epithelioid granulomas.     

Pelvic abscess from enterobius vermicularis. Report of a case with cytologic detection of eggs and worms

BACKGROUND: Enterobius vermicularis is known to produce perianal and ischioanal abscesses and invade the peritoneal cavity via the female reproductive system, causing pelvic peritonitis. However, there are only rare case reports on the cytodiagnosis of these parasitic lesions. CASE: A 28-year-old woman was admitted with a tender left iliac fossa mass and greenish vaginal discharge. Ultrasonogram and computed tomography scan confirmed the presence of a mass lesion suggestive of a tuboovarian abscess. Cytologic examination of the pus obtained during left salpingo-oophorectomy revealed the presence of ova of E vermicularis and fragments of the adult worm in an inflammatory exudate consisting predominantly of neutrophils, eosinophils and occasional epithelioid cell granulomas. Paraffin sections of the tuboovarian mass showed necrotizing epithelioid cell granulomas, but neither ova nor any worm section was identified. Although the possibility of tuberculosis was considered histologically, Ziehl-Neelsen (Z-N) stain for acid-fast bacilli was negative. Z-N staining of the smear and mycobacterial culture of the pus also did not yield positive results. CONCLUSION: E vermicularis may cause tuboovarian abscess with necrotizing epithelioid granulomas mimicking tuberculosis. Cytologic examination of the pus is helpful in the diagnosis.     

Concentration of Lymph Node Aspirate Improves the Sensitivity of Acid Fast Smear Microscopy for the Diagnosis of Tuberculous Lymphadenitis in Jimma,Southwest Ethiopia

Background

Tuberculous lymphadenitis (TBLN) is the most common form of extrapulmonary tuberculosis. The cytomorphological features of lymph node smears have reduced specificity for the diagnosis of tuberculosis. The diagnosis of TBLN with direct smear microscopy lacks sensitivity due to the limited number of bacilli in lymph node aspirate. Therefore, we aimed to assess whether the concentration of lymph node aspirate improves the sensitivity of acid fast smear microscopy for the diagnosis of tuberculous lymphadenitis.

Methods

A cross-sectional comparative study was conducted on 200 patients clinically suspected for tuberculous lymphadenitis in Jimma, Ethiopia. Lymph node aspirate was collected. The first two drops were used for cytomorphological study and direct acid fast staining. The remaining aspirate was treated with N-acetyl-L-cysteine (NALC) and concentrated by centrifugation at 3000 g for 15 minutes. The sediment was used for acid fast staining and culture. Differentiation of M. tuberculosis complex (MTBC) from non-tuberculous mycobacteria (NTM) was done by para-nitrobenzoic acid susceptibility test.

Result

Complete data were available for 187 study subjects. 68% (127/187) were positive for M. tuberculosis on culture. Four isolates, 2.1% (4/187), were identified as NTM. The detection rate of direct smear microscopy was 25.1% and that of the concentration method 49.7%. Cytomorphologically, 79.7% of cases were classified as TBLN. The sensitivity of direct smear microscopy was 34.6%, for concentrated smear microscopy 66.1%, and for cytomorphology 89.8%. Two AFB positive cases on concentration method were non-tuberculosis mycobacteria (NTM). The concentration method yielded a positive result from seven cases diagnosed as suppurative abscess by cytology. Both for the direct and concentration methods the highest rate of AFB positivity was observed in smears showing caseous necrosis alone. Smear positivity rate decreased with the appearance of epithelioid cell aggregates.

Conclusion

The concentration of lymph node aspirates for acid fast smear microscopy had significantly higher sensitivity than direct microscopy.     

The Spectrum of Extrapulmonary Tuberculosis

The incidence of new cases of extrapulmonary tuberculosis has remained constant, despite the decline in new cases of active pulmonary tuberculosis. This might be due to a delay in recognition, and particularly a lack of consideration of tuberculosis when the presenting symptoms are other than respiratory. Extrapulmonary tuberculosis should be considered in the differential diagnosis of bone, joint, genitourinary tract and central nervous system (CNS) diseases.To determine factors that might delay recognition and identification, 62 patients having extrapulmonary tuberculosis during 1969-1972 at the Los Angeles County-University of Southern California Medical Center were studied.Three quarters of these patients had had CNS, skeletal or genitourinary tuberculosis in equal distribution or 25 percent each. CNS involvement was seen frequently in the disseminated form. Presenting symptoms were protean and not specific, such as fever, anorexia, weight loss, cough, lymphadenopathy and neurologic abnormalities. Roentgenograms of the chest were abnormal in most. When a roentgenogram of the chest suggests pulmonary tuberculosis, signs and symptoms in other body systems should suggest extrapulmonary tuberculosis. If no abnormalities are seen on a roentgenogram of the chest, however, this does not preclude the diagnosis of extrapulmonary tuberculosis. Neither does a negative tuberculin skin test exclude the condition.Abnormal laboratory findings are common, especially in disseminated tuberculosis. These include various anemias, bone marrow disorders, hyponatremia due to inappropriate antidiuretic hormone syndrome. Analyses of pleural, peritoneal, pericardial and joint fluid usually show an exudate high in lymphocytes and occasionally low in glucose. Similar findings are seen in spinal fluid. The histological features of caseous or noncaseous granulomas are suggestive of but not specific for tuberculosis. Only culture of mycobacteria from sputum, urine, spinal fluid, pleural and other effusions and tissue biopsy specimens will yield a definitive diagnosis.Physicians must have a high index of suspicion to diagnose extrapulmonary tuberculosis, as it can resemble any disease in any organ system. Immediate therapy in the disseminated variety, sometimes even before a definite diagnosis can be made, may be lifesaving.     

Pathology of cat-scratch disease

A pathologic and histogenetic study of material obtained from ten cases of cat-scratch disease was carried out. The earliest lesion was of ten days' duration and the oldest of 35 days' duration. The first changes in lymph nodes consisted of proliferation of epithelioid cells followed by exudation of leukocytes in their centers and subsequent necrosis of the exudate and epithelioid cells. Proliferative changes leading to formation of epithelioid cell tubercles were seen in some cases. Homogenization of necrotic centers brought about the formation of caseous tubercles similar to those seen in tuberculosis, syphilis, lymphogranuloma venereum and tularemia. Differentiation and the final diagnosis of cat-scratch disease rests upon correlation of histopathologic observations, clinical studies and specific skin tests.