Mediastinal pleomorphic liposarcoma diagnosed by fine needle aspiration biopsy: a case report

BACKGROUND: Progress in radiology and pathology for diagnosing mediastinal tumors has R been made in recent decades, thanks to the use of fine needle aspiration biopsy (FNAB) guided by computed tomography, which has replaced mediastinoscopy and open biopsies. CASE: A 66-year-old male had a history o productive coughing with mucopurulent expectoration, progressive dyspnea, arthralgias, myalgias, astenia and adynamia for the previous 3 months. A CT scan and magnetic resonance imaging revealed a poorly limited tumor mass ofheterogeneous den sity in the anterior mediastinum. FNAB of the tumor mass showed malignant cells compatible with liposarcoma. CONCLUSLON: Of the several types of mesenchymal mediastinal neoplasms, liposarcoma is the most important. Many of them are seen in adults, and <10 cases have been diagnosed in children. The symptoms are related to compression of the nearby airways. Usually liposarcomas are yellow, lobed tumors without capsules that infiltrate adjacent organs and tissues. Microscopically, they have the same histologic spectrum as tumors originating in other sites. Thus, it is common to observe all the histologic varieties of soft tissue liposarcomas. The identification of lipoblasts is the key to the correct diagnosis in FNAB material.     

Diagnosis of cervical thymoma by fine needle aspiration biopsy with flow cytometry. A case report

BACKGROUND: Cervical thymoma is a rare entity. To our knowledge, this is the 20th reported case of cervical thymoma and the fourth case of fine needle aspiration biopsy (FNAB) of this entity. To our knowledge, this is the only case in which cervical thymoma was a diagnostic consideration at the time of the FNAB diagnosis. The diagnosis was rendered because, unlike in previous cases, flow cytometric immunophenotyping was performed. CASE: A 46-year-old, white female presented with what was clinically thought to be a left thyroid nodule. The patient underwent FNAB at an outside institution, and the diagnosis of "possible mixed lymphoma" was made by morphology alone. The patient was referred to our institution for repeat FNAB. Based upon the cytologic findings (cells with lymphoid morphology), flow cytometry was performed, and a diagnosis of cervical thymoma (versus ectopic thymic tissue) was based upon flow cytometry findings combined with morphology. CONCLUSION: When FNAB of a cervical mass, particularly one clinically thought to be a thyroid nodule, shows lymphoid cells without thyroid follicular cells, immunophenotyping may be extremely helpful in arriving at the correct diagnosis.     

Multilocular thymic cyst with follicular lymphoid hyperplasia in a male infected with HIV. A case report with fine needle aspiration cytology

BACKGROUND: Multilocular thymic cyst with follicular lymphoid hyperplasia is a rare complication in HIV-infected patients, causing pseudotumorous enlargement of the anterior mediastinum. There have been six reported cases, all with only histologic findings. This paper reports another such case and includes perhaps the first cytologic findings on this rare entity. CASE: A 35-year-old, HIV-infected male intravenous drug abuser, who complained of worsening central chest discomfort and pain on deep inspiration, was found to have a large, septated anterior mediastinal mass. Computed tomography-guided fine needle aspiration biopsy was performed. The cytologic presentation mimicked that of thymoma, with cystic degeneration and a dual population of epithelial cells and lymphocytes as well as large aggregates of "epithelial" cells intermixed with lymphocytes in a background of macrophages and cyst fluid. Histologic examination of the resected mass revealed a multilocular thymic cyst with follicular lymphoid hyperplasia. HIV-1 core protein p24 was localized immunohistochemically in the dendritic follicular cells of the germinal centers. In retrospect, the quantity of epithelium derived from the cyst lining was too scanty for thymoma, and the presence of plasma cells and lymphohistiocytic aggregates suggested follicular lymphoid hyperplasia. CONCLUSION: Multilocular thymic cyst with follicular lymphoid hyperplasia should be considered in the differential diagnosis of an anterior mediastinal mass in HIV-infected patients after lymphoma and tuberculosis.     

Cytopathologic features of pituitary carcinoma with cervical vertebral bone metastasis: a case report

BACKGROUND: Pituitary carcinomas are extremely rare tumors of the adenohypophysis. The presence of craniospinal and/or systemic extracranial metastases is the only reliable criterion for the diagnosis of pituitary carcinoma. To date, only 2 cases have been reported correctly by fine needle aspiration biopsy (FNAB). We present an additional case of pituitary carcinoma with FNAB features. CASE: A 60-year-old woman presented with clinical features of Cushing's disease and a pituitary tumor. She underwent transsphenoidal resection of the tumor. The initial diagnosis was an adrenocorticotrophic hormone (ACTH)-producing invasive pituitary adenoma. The patient presented again with neck pain 6 years after the operation. Magnetic resonance imaging revealed metastatic tumor masses at the level of C5-C6 of the cervical vertebrae. Intraoperative fine needle aspiration and incomplete excision of metastatic tumors were performed. Cytologically, tumor cells were composed of a combination of loose groups and single cells. Neoplastic cells had a relatively monotonous appearance and displayed characteristic neuroendocrine tumor features. Immunocytochemistry from cell block sections revealed AE1/ AE3, synaptophysin chromogranin A and ACTH positivity in the tumor cells. CONCLUSION: Pituitary carcinoma with extracranial systemic metastases demonstrates typical neuroendocrine features on fine needle aspiration. In the differential diagnosis, metastatic neuroendocrine carcinomas should be kept in mind. In the absence of sufficient clinical data, these 2 entities cannot be distinguished correctly through the cytologic features.     

Sebaceous lymphadenoma identified by fine needle aspiration biopsy: a case report

BACKGROUND: Sebaceous lymphadenoma of the parotid gland is a rare benign neoplasm. This is the first reported case of fine needle aspiration biopsy (FNAB) findings for sebaceous lymphadenoma of the parotid gland. CASE: A 60-year-old male presented with painless, bilateral parotid swelling noted for 5 months. The swelling was more pronounced on the right. Examination revealed bilaterally prominent parotid glands with diffuse firmness but no discrete masses. There was no evidence of facial nerve dysfunction. Laboratory evaluation was negative for infectious and autoimmune etiologies. Magnetic resonance imaging revealed bilateral cystic parotid masses. FNAB of the right parotid was obtained to assist with preoperative counseling. It revealed lymphoid and salivary gland parenchymal cells. The patient underwent a right superficial parotidectomy. The surgical specimen of the parotid mass confirmed the diagnosis of sebaceous lymphadenoma on the tissue section. The contralateral parotid mass had not been excised at this writing. CONCLUSION: This report is the first to describe the FNAB findings of the unusual benign parotid neoplasm sebaceous lymphadenoma. Though the definitive diagnosis of any parotid mass requires tissue, generally obtained via parotidectomy, an FNAB diagnosis can be useful in counseling a patient prior to definitive biopsy.     

Cytologic diagnosis of alveolar soft part sarcoma of the lower extremity by fine needle aspiration and correlation with core biopsy: a case report

BACKGROUND: Alveolar soft part sarcoma is a rare soft tissue tumor of uncertain origin that is generally slow growing but unmistakably malignant due to its propensity for metastasis to lung, bone and brain early in the course of disease. Fine needle aspiration biopsy (FNAB) of these tumors and recognition of the characteristic cytologic features precludes more invasive diagnostic measures and facilitates appropriate treatment. CASE: A 54-year-old African-American man presented to our institution with a 2-week history of left leg pain. Imaging studies revealed a left leg soft tissue mass just below the popliteal fossa and multiple bilateral lung lesions suggestive of metastatic neoplasm. FNAB of the left lower extremity mass yielded uniform clusters of cells and sigle cells with large nuclei and single prominent nucleoli. Histologically, the biopsy showed nests of large polygonal cells with abundant eosinophilic cytoplasm, round regular nuclei and prominent nucleoli. A periodic acid-Schiff (PAS) stain highlighted intracytoplasmic rhomboidal crystals, a feature diagnostic of alveolar soft part sarcoma. CONCLUSION: Alveolar soft part sarcoma may be diagnosed by its unique morphologic characteristics and should be considered in the differential diagnosis of all cytologically sampled soft tissue lesions.     

Fine needle aspiration biopsy with adjunct immunohistochemistry in intraocular tumor management

OBJECTIVE: To assess the effectiveness of fine needle aspiration biopsy (FNAB), with and without immunohistochemistry (IHC), in the management of solid intraocular tumors. STUDY DESIGN: Thirty-three consecutive adults undergoing FNAB of suspected intraocular tumors were studied. Clinical, cytologic and histologic diagnoses were correlated. The positive predictive value, sensitivity and specificity of FNAB for detecting malignancy, the effect of lHC on the final cytologic diagnosis and the number of patients in whom clinical management was altered as a result of cytologic evaluation were determined. RESULTS: The positive predictive value was 96% with and 93% without adjunct IHC. The sensitivity and specificity of FNAB for detecting malignancy were 96% and 83%, respectively, with IHC. Without IHC, the sensitivity was unaltered, but the specificity was 67%. IHC confirmed the morphologic diagnosis in 75% of cases, made a diagnosis in 12.5% and changed a malignant diagnosis from carcinoma to melanoma in 6% of cases. The planned management was changed by the FNAB findings in 24% of patients. In 3 patients (9%), IHC was essential for diagnosis and management. No patients exhibited local tumor dissemination or recurrence associated with the biopsy. CONCLUSION: FNAB is a safe, sensitive and specific method of establishing a tissue diagnosis in a subset of patients with solid intraocular tumors. The routine use of immunohistochemical stain ing increases the diagnostic utility of the technique and may change clinical management.     

Adenomyomatous hamartoma of lung mimicking benign mucinous tumor in fine needle aspiration biopsy: a case report

BACKGROUND: Typical cytologic features of pulmonary hamartoma (PH) are usually smears of hyaline cartilage, fibrous tissue, smooth muscle, adipocytic components and respiratory epithelium. Cytologic features of adenomyomatous hamartoma, a special variant of PH, are not documented in the literature and are confused with epithelial neoplasm in the case of sparse stromal cellularity. CASE: A 59-year-old man presented with a solitary pulmonary nodule by chest radiograph at his routine health examination. Fine needle aspiration biopsy (FNAB) revealed numerous mucinous epithelial cells presenting predominantly in cohesive cellular sheets that suggested benign mucinous epithelial lesion. The patient underwent surgery for the tumor, and it was histologically proven to be an adenomyomatous hamartoma. CONCLUSION: An unusual type of PH could lead to misdiagnosis by FNAB in the case of few stromal components. This case demonstrates the wide spectrum of PH in FNAB and led us to consider PH as a differential diagnosis despite lack of chondromyxoid stromal components.     

Fine needle aspiration diagnosis of lymphomatoid granulomatosis. A case report.

The diagnosis of lymphomatoid granulomatosis (LG) of the lung depends on obtaining adequate histologic material to demonstrate the characteristic angioinvasive, polymorphous, lymphoid infiltrate and normally requires an open lung biopsy. Fine needle aspiration biopsy (FNAB), if only smeared directly, does not allow an assessment of the lymphoid infiltrate in relation to blood vessels. However, we report a case diagnosed by FNAB in which the specimen was processed by an alternative method that allows cell blocks to be made from all visible particles. Percutaneous FNAB of a nodular pulmonary infiltrate was performed after bronchoscopy and transbronchial needle biopsy failed to yield a diagnosis. The FNAB specimen was placed in 50% alcohol and submitted for processing. The specimen was then filtered through a fine sieve, and all visible tissue was embedded in bacteriologic agar and processed as a standard surgical specimen. The filtrate was processed as standard fluid cytology. The atypical, angioinvasive, lymphoid infiltrate was clearly demonstrated on the cell blocks, and the diagnosis of LG was made. This diagnosis was confirmed by subsequent open lung and skin biopsies.     

Fine needle aspiration biopsy of mixed medullary-follicular thyroid carcinoma. A report of two cases

BACKGROUND: Mixed differentiated thyroid carcinomas are rare tumors, difficult to recognize on fine needle aspiration biopsy (FNAB). Most cases are diagnosed only after histologic investigation. CASES: The cases entailed two cytologic samples and a thyroidectomy specimen. Two FNAB thyroidectomy specimens from a 60-year-old man presenting with a solitary thyroid nodule (case 1) were investigated. Both cytologic samples were referred as atypical, with a mixture of features indicating a proliferating follicular lesion but also containing some characteristics of medullary carcinoma. The serum calcitonin level was borderline. Surgery was recommended because of a suspicion of malignancy. The diagnosis of mixed medullary follicular carcinoma was established after a complex histologic investigation. The tumor was encapsulated, with partly microfollicular architecture. Immunohistochemistry was positive for both calcitonin and thyreoglobulin. Electron microscopy from the formol-paraffin block found neurosecretory granules in many cells. The patient was well one year after the operation. One FNAB and thyroidectomy specimen from a 47-year-old woman with long-treated lymphoplasmocellular thyroiditis (case 2) was investigated. The tumor in case 2 was diagnosed on FNAB as medullary carcinoma. Only after histologic and immunohistochemical investigation was mixed differentiation proven. CONCLUSION: Mixed differentiated thyroid tumors are a diagnostic challenge on fine needle aspiration. Irrespective of their rarity, they can be suspected if combined features are present. FNAB recognition of the medullary component in both cases was of crucial importance. Nevertheless, definitive diagnosis remains a histologic problem due to the necessity for topographic information.     

Fine-needle aspiration biopsy cytology of cutaneous calcinosis in a 74-year-old woman with dermatomyositis on methotrexate therapy: a case report

BACKGROUND: Cutaneous calcinosis (CC) occurs in a variety of rheumatic diseases. Fine needle aspiration biopsy (FNAB) may be used in the office setting to evaluate such soft tissue lesions. For patients on methotrexate (MTX) therapy, methotrexate nodulosis (MN) should be considered in the differential diagnosis. CASE: A 74-year-old Caucasian woman with adult-onset dermatomyositis (ADM) on MTX therapy presented for evaluation of a right breast mass and multiple soft tissue nodules. FNABs of the right breast mass and a left upper extremity nodule both demonstrated benign calcified material. Six months later, the patient returned for evaluation of the persistent right breast mass and repeat FNAB revealed adenocarcinoma. Concurrently, a right hip soft tissue nodule was aspirated, demonstrating benign crystalline debris. MTX therapy was discontinued, and the patient subsequently underwent a lumpectomy of the right breast 1 month after FNAB diagnosis, displaying infiltrative ductal carcinoma. Of note, 2 months after her lumpectomy, MTX therapy was restarted and the patient continues to have adequate control of ADM symptoms with persistent, clinically benign soft tissue calcifications. CONCLUSION: Performing FNAB on soft tissue lesions can obviate needless tissue biopsies of CC in appropriate rheumatology patients, thus avoiding the risks and complications associated with more invasive procedures.     

Fine needle aspiration biopsy of neuroendocrine breast carcinoma metastatic to the thyroid. A case report

BACKGROUND: Tumors showing neuroendocrine differentiation arise in a wide range of organs, and metastatic neuroendocrine tumors may be difficult to differentiate from primary tumors. This report describes an unusual case of metastatic breast carcinoma with neuroendocrine differentiation that presented as a solitary thyroid nodule. The diagnosis was made by fine needle aspiration biopsy (FNAB). CASE: A 52-year-old woman presented with a thyroid nodule and bilateral enlarged supraclavicular fossa lymph nodes. FNAB revealed a neuroendocrine carcinoma. Further questioning revealed that the patient had had a breast carcinoma resected eight years previously. The diagnosis of metastatic neuroendocrine breast carcinoma was established by immunocytochemistry. The patient received antiestrogen therapy but subsequently developed skeletal metastases. CONCLUSION: Neuroendocrine carcinomas from various sites show similar cytologic features. In this case, a diagnosis of breast carcinoma metastatic to the thyroid was suggested by the clinical history and confirmed by FNAB with immunocytochemistry.     

Retroperitoneal extramedullary anaplastic plasmacytoma masquerading as sarcoma: Report of a case with an unusual presentation and imprint smears

BACKGROUND: Extramedullary plasmacytoma of the retroperitoneum is rare. Furthermore, plasmacytoma with anaplastic features can be confused with high grade sarcoma clinically and histologically, particularly when the initial immunohistochemical tumor markers are negative. However, paying attention to cytologic imprint smears can give valuable clues to the correct diagnosis. CASE: A 73-year-old male was admitted to our hospital with a recent history of back pain. Abdominal computed tomography revealed a large retroperitoneal mass (6.8 x 5.1 cm). The initial pathologic evaluation revealed a high grade pleomorphic neoplasm that failed to express multiple epithelial, mesenchymal, lymphoid and melanoma immunohistochemical markers. Subsequent fresh tissue evaluation with touch imprints and immunophenotypic characterization confirmed the plasma cell origin of the tumor. Thorough retrospective review of the touch imprint smears clearly showed the plasmacytic cytologic features. Features of multiple myeloma were essentially absent. CONCLUSION: Performing cytologic imprint smears on fresh tissue material may help in making the correct diagnosis and is highly recommended.     

Crystals of alveolar soft part sarcoma in a fine needle aspiration biopsy cytology smear. A case report

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor. It has characteristic histomorphology, with typical ultrastructural features demonstrating unique crystalloids. It occurs predominantly in adolescents and young adults, in whom the most common location is within the fascial planes of skeletal muscle of the lower extremity. CASE: We present fine needle aspiration biopsy (FNAB) findings along with histopathologic features and ultrastructural appearance of a large gluteal mass in a 29-year-old female. FNAB cytology smears showed single and small groups of polyhedral malignant cells with granular cytoplasm, anisokaryosis and prominent nucleoli. The delicate cytoplasm had a tendency to rupture, with the presence of many bare nuclei. The characteristic crystals were observed in Papanicolaou-stained smears within the cytoplasm and in the background near the tumor cells. This consolidated the radiologic suspicion of ASPS and facilitated the application of relevant ancillary tests. Biopsy of the mass showed the characteristic histologic pattern. Electron microscopy confirmed the diagnosis with demonstration of membrane-bound, rhomboid crystalloids with a latticelike ultrastructure. CONCLUSION: Detection of characteristic crystalloids in Papanicolaou-stained FNAB smears facilitated a proper evaluation and correct diagnosis of ASPS.     

Anaplastic large cell lymphoma of the mediastinum diagnosed by transbronchial scratch cytology. A case report

BACKGROUND: Anaplastic large cell lymphoma (ALCL) is a subtype of non-Hodgkin's lymphoma characterized by CD30 antigen-positive, large neoplastic cells. We describe a case of ALCL suggested by cytologic examination of the tumor cells obtained from bronchial scratch preparations. CASE: A 26-year-old woman had had a dry cough since November 1996. Chest radiography in May 1997 revealed an abnormal shadow in the mediastinum extending to the pulmonary hilar region. The patient was hospitalized in June 1997. Computed tomography revealed a neoplastic lesion in the anterior mediastinum invading the right lung. Transbronchial scratch cytology revealed large, atypical lymphoid cells expressing CD30 and CD3 on immunocytochemical examination. A transcutaneous mediastinal biopsy was performed and a diagnosis of ALCL made. CONCLUSION: Differentiation from Hodgkin's disease was the most difficult point in this case. Detailed cytologic observation and CD3-positive immunocytology led to the correct diagnosis. The cell transfer technique of Sherman et al was very useful for immunocytologic staining. Thus, transbronchial scratch cytology was an especially valuable and effective procedure in this case.     

Fine needle aspiration appearance of extragastrointestinal stromal tumor. A case report

BACKGROUND: Gastrointestinal stromal tumors (GISTs) rarely develop outside the digestive tract and in the soft tissues of abdomen and retroperitoneum. Such tumors are designated extra-GISTs (EGISTs). Cytologic and immunocytochemical features of a case of EGIST are reported. CASE: A 54-year-old woman presented with a peritoneal mass, diameter 22 cm, adherent to the omentum and without a connection to the digestive tract. Fine needle aspiration biopsy (FNAB) of the excised tumor showed high cellularity in two patterns: monotonous spindle cells were intermingled with a mildly atypical epithelioid component. Immunocytochemistry performed on cytospins revealed reactivity for c-kit (CD117), CD34 and smooth muscle actin and negativity for S-100. The findings were concordant with a histologic diagnosis of EGIST. CONCLUSION: EGISTs are infrequent neoplasms and can be diagnosed in FNAB samples. The clinical/radiologic setting must be considered together with the cytologic features. Immunocytochemistry is a clue to the diagnosis when it detects c-kit reactivity.     

Unusual cases of metastases to the breast. A report of 17 cases diagnosed by fine needle aspiration

BACKGROUND: Although nonmammary tumors metastatic to the breast are relatively uncommon, a correct diagnosis is essential to appropriate management. Radiologically these lesions are single, round, discrete lesions without the spiculations of primary malignancies. Fine needle aspiration biopsy (FNAB) may provide a definitive diagnosis, thereby sparing patients unnecessary surgery. CASES: Seventeen cases of nonmammary malignancies diagnosed by fine needle aspiration of the breast were identified in the cytopathology files at three different institutions from 1989 to 1999. Three of the cases are of particular interest, including a mucoepidermoid carcinoma of salivary gland origin and a small cell undifferentiated carcinoma of rectal origin, neither of which has been reported in the literature previously. The third case was a male with a breast mass that was originally thought to be primary based on clinical, cytologic and immunocytochemical features but subsequently was determined to be a metastasis from the lung. CONCLUSION: Virtually any malignancy may metastasize to the breast. FNAB is the best approach to the diagnosis of tumors that either clinically or radiographically are not typical of primary breast tumors. Extramammary neoplasms metastatic to the breast may be definitively diagnosed by FNAB, resulting in the most appropriate as well as cost-effective patient management.     

Desmoplastic small round cell tumour: Cytological and immunocytochemical features

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive neoplasm. The cytological diagnosis of these tumors can be difficult because they show morphological features quite similar to other small round blue cells tumors. We described four cases of DSRCT with cytological sampling: one obtained by fine needle aspiration biopsy (FNAB) and three from serous effusions. The corresponding immunocytochemical panel was also reviewed. METHODS: Papanicolaou stained samples from FNAB and effusions were morphologically described. Immunoreaction with WT1 antibody was performed in all cytological samples. An immunohistochemical panel including the following antibodies was performed in the corresponding biopsies: 34BE12, AE1/AE3, Chromogranin A, CK20, CK7, CK8, Desmin, EMA, NSE, Vimentin and WT1. RESULTS: The smears showed high cellularity with minor size alteration. Nuclei were round to oval, some of them with inconspicuous nucleoli. Tumor cells are clustered, showing rosette-like feature. Tumor cells in effusions and FNA were positive to WT1 in 3 of 4 cytology specimens (2 out 3 effusions and one FNA). Immunohistochemical reactions for vimentin, NSE, AE1/AE3 and WT1 were positive in all cases in tissue sections. CONCLUSION: The use of an adjunct immunocytochemical panel coupled with the cytomorphological characteristics allows the diagnosis of DSRCT in cytological specimens.     

Asymptomatic intrathyroidal parathyroid adenoma. Report of a case with a cytologic differential diagnosis including thyroid neoplasms

BACKGROUND: Intrathyroidal parathyroid neoplasms (IPNs) are uncommon tumors with an indolent clinical course. When asymptomatic, they can be incorrectly diagnosed as thyroid neoplasms on fine needle aspiration biopsy (FNAB), leading to inappropriate surgical treatment. CASE: A case of unsuspected IPN occurred in which the cytologic picture mimicked that of a thyroid neoplasm. The histologic specimen of the total thyroidectomy showed 2 adjacent intrathyroidal nodules morphologically and immunohistochemically corresponding to a parathyroid adenoma. CONCLUSION: The incidence of IPN remains controversial, especially in asymptomatic patients. On FNAB it is a possible cause of inappropriate surgery for a suspicious thyroid neoplasm (follicular or medullary carcinoma). Immunostaining for parathormone on the cytologic smear is valuable in establishing the correct preoperative diagnosis when the morphologic features are strongly suggestive of IPN.     

Cytodiagnosis of lymphoid proliferations by fine needle aspiration biopsy. Adjunctive value of flow cytometry

OBJECTIVE: To determine the accuracy of fine needle aspiration biopsy (FNAB) complemented by flow cytometry (FC) for the diagnosis of reactive and neoplastic lymphoid proliferations and subclassification of malignant lymphomas. STUDY DESIGN: Forty-one FNABs of lymphoid lesions on which FC had been performed were evaluated retrospectively. All cases were correlated with histology or clinical follow-up. RESULTS: Twelve FNABs were diagnosed as reactive. Eleven of the 12 were confirmed as reactive on follow-up. One was a case of posttransplant lymphoproliferative disorder. Twenty-five FNABs diagnosed as lymphoma were confirmed by histology. In 22 of these 25 cases, there was 100% correlation between the subclassification given on FNAB with FC and that given on histology. Two of the remaining cases, which were correctly called follicular center cell lymphoma, showed discrepancies in grading. One case called Hodgkin's disease on FNAB was T-cell lymphoma on histology. Of four FNABs given an inconclusive diagnosis, two were lymphoma on follow-up, and two were reactive. CONCLUSION: FNAB examination, when it includes immunophenotyping by FC, is a useful technique for distinguishing reactive lymphoid proliferations from malignant lymphomas and for the subclassification of lymphomas.