Oncocytic carcinoid tumor of the lung: a case report of diagnostic pitfall in filter membrane preparation of bronchial washings

BACKGROUND: Oncocytic carcinoid tumor of the lung is a rare variant of pulmonary carcinoid. This report describes the morphologic appearance of this rare tumor on filter membrane preparation along with potential pitfalls. CASE: A 49-year-old woman presented with cough and expectoration. On chest radiograph a mass lesion was seen in the upper zone of the right lung. Bronchial washings were sent for evaluation. On filter membrane (Millipore) preparation of bronchial washing the possibility of a non-small cell carcinoma, possibly squamous, was suggested. Right upper lobectomy was subsequently performed and a histologic diagnosis of oncocytic carcinoid given. The cytomorphologic features of this tumor on the Millipore preparation were reviewed. CONCLUSION: Differential diagnosis of oncocytic carcinoid should be kept in mind while assessing cytologic material when tumor cells show abundant granular cytoplasm and prominent nucleoli. Oncocytic carcinoid also must be differentiated from oncocytoma and granular cell tumor. Immunocytochemistry and electron microscopy are useful in confirming the diagnosis.     

Cytology of benign multicystic peritoneal mesothelioma in peritoneal washings

Objective:  To describe the cytological aspect of peritoneal washings in benign multicystic peritoneal mesothelioma (BMPM).
Methods:  Three peritoneal washing specimens stained by standard cytological and histological procedures and analysed by light microscopy.
Results:  The specimens showed an abundance of monomorphous mesothelial cells devoid of atypia or mitoses. The mesothelial cells were calretinin positive. They also showed numerous squamous metaplastic cells arranged in flat sheets or isolated cells. The background contained some inflammatory cells.
Conclusion:  The combination of cytology of the peritoneal washing, histology (cell block and surgical specimen) and clinical history allow differentiation of BMPM from other cystic lesions (cystic lymphangioma and malignant mesothelioma).     

Pulmonary tumorlet: a case report of a diagnostic pitfall in cytology

BACKGROUND: Pulmonary tumorlets are usually an incidental pathologic curiosity of no clinical importance, but may be mistaken for epithelial and nonepithelial neoplasms. Fine needle aspiration (FNA) of this cell proliferation has rarely been reported. We describe a pulmonary tumorlet associated with bronchocentric granulomatosis presenting as a tumorous consolidation on chest radiograph. CASE: In a hitherto healthy 70-year-old man admitted for acute respiratory infection, a solid consolidation was found on chest radiograph. Medical history was uneventful except right-sided pleurisy in 1949. Computed tomography-guided FNA sample was composed of loose clusters of small columnar cells with cyanophilic cytoplasm and centrally located round to oval nuclei. With a tentative diagnosis of well-differentiated adenocarcinoma, lumpectomy was performed. Intraoperative cytology demonstrated lymphocytes, epithelioid cells, giant cells of Langerhans type and clusters of columnar cells. Definitive histologic examination confirmed the intraoperative diagnosis of necrotizing granulomatosis and tumorlet. Neuroendocrine origin of the cells was confirmed by immunocytochemical and immunohistochemical studies resulting in strong reactivity of the cells to synaptophysin, NSE, chromogranin A and N-Cam. CONCLUSION: Knowledge of the cytomorphologic presentation of tumorlets in FNA and consideration of the appropriate differential diagnoses combined with ancillary studies might have prevented lung resection.     

Extraneous cells of hepatic origin in adrenal fine needle aspiration as a diagnostic pitfall: a case report

BACKGROUND: The fine needle aspiration (FNA) cytologic evaluations of most adrenal lesions are straightforward. However, there are diagnostic pitfalls to be avoided. CASE: A 34-year-old, pregnant woman was discovered to have an asymptomatic, right upper abdominal mass on ultrasound examination. After delivery, computed tomography-guided FNA showed bland epithelial cells, and a diagnosis of adrenal cortical adenoma was made. However, subsequent resection showed a myelolipoma of the adrenal gland. CONCLUSION: This case illustrated 2 cytodiagnostic pitfalls in adrenal fine needle aspirates. First, the myeloid cells characteristic of a myelolipoma were not present in the FNA smears because a large portion of the lesion was composed of fibroadipose tissue. Second, extraneous, benign cells of hepatic origin were misinterpreted as adrenal cortical adenoma cells.     

Neuroendocrine tumor in gastric adenoma: a diagnostic pitfall mimicking invasive adenocarcinoma

ABSTRACT: Neuroendocrine tumor (NET) in adenoma of the gastrointestinal tract is a rare mixed glandular-endocrine neoplasm and has uncommonly been described mostly in the colon. Histologically, this tumor is composed of a predominant proportion of benign adenomatous component and a small portion of well-differentiated NE component. Only three cases of NET in gastric adenoma have been reported in the literature. We present 4 cases of NET in gastric adenoma mimicking invasive adenocarcinoma. The NETs were 0.62 mm to 4.1 mm in size and located at the basal lamina propria, muscularis mucosa and submucosa. Histologically, NETs consisted of nests, cords, tubules, and clusters of cells that predominantly interposed between the foveolar base without disturbing the overall polyp architecture. The lesions were completely removed by endoscopic submucosal dissection in three cases and in one case, subtotal gastrectomy was performed because endoscopic biopsy was invasive adenocarcinoma. The patients' clinical course was uneventful without an evidence of recurrence or metastasis. The recognition of NET in gastric adenoma will help avoid potential diagnostic pitfalls masquerading as invasvie adenocarcinomas posed by their infiltrative pattern into submucosa.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1688552293761001.     

Atypical squamous cells as a diagnostic pitfall in pulmonary Wegener's granulomatosis. A case report

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic, necrotizing, granulomatous inflammation accompanied by vasculitis. It classically involves the triad of the upper respiratory tract, lungs and kidneys. Isolated pulmonary lesions of WG may present in some patients as pulmonary masses, simulating neoplasms. The features of WG can be suggested by cytologic study. Atypical epithelial cells associated with WG have previously been reported as a cause of a false positive diagnosis of bronchoalveolar carcinoma. CASE: In this case the cytologic findings included atypical squamous cells in a background of acute, chronic and granulomatous inflammation. In several respiratory specimens the atypical squamous cells were incorrectly interpreted as diagnostic of squamous cell carcinoma. The correct diagnosis of WG was confirmed with open lung biopsy, which demonstrated necrotizing granulomatous inflammation with geographic necrosis and associated vasculitis. CONCLUSION: Markedly atypical squamous cells mimicking squamous cell carcinoma can be found accompanying the inflammatory process associated with WG and are a possible diagnostic pitfall. The possibility of WG as well as other inflammatory processes should always be considered in the differential diagnosis of squamous cell carcinoma of the lung. This case is the only reported case of WG in which atypical squamous cells were a diagnostic pitfall, initially suggesting a diagnosis of squamous cell carcinoma.     

Highly specific marker genes for detecting minimal gastric cancer cells in cytology negative peritoneal washings

Peritoneal wash cytology plays a pivotal role in the decision for gastric cancer treatment because advanced gastric cancer often turns out incurable with peritoneal metastasis. Molecular detection of minimal cancer cells from peritoneal washings may overcome the sensitivity boundary of conventional cytology and contribute to the prediction of the disease outcome. To select marker candidates out of ten thousands of genes, we performed microarray analyses in 12 gastric cell lines and 8 peritoneal washings of early stage cases. With 40 candidates selected by the above expression profiling, RT-PCR in 16 representative peritoneal wash samples was performed to identify genes specific to cytology positive samples. The finally selected five genes, CK20, FABP1, MUC2, TFF1, and TFF2, were then evaluated for their utility as a marker for minimal residual disease in 99 peritoneal wash samples. Nested RT-PCR using the five genes showed positive results highly specific to incurable cases (91-100%). With a high specificity, the combination of these five genes succeeded in identifying 6 out of 20 (30%) additional patients with all types of early recurrence that could not be predicted by the conventional method. The six newly identified recurrences included four non-peritoneal ones, showing that RT-PCR using the five genes without a real-time quantitative PCR technique contributes to the detection of minimal residual disease.     

Pilomatrixoma as a diagnostic pitfall in fine needle aspiration cytology: a case report

BACKGROUND: Pilomatrixoma (pilomatrixoma, calcifying epithelioma of Malherbe) is a relatively uncommon, benign neoplasm arising from the skin adnexa. The tumor can cause diagnostic difficulty not only for the clinician but also for the cytologist. CASE: A 62-year-old woman presented with a right submandibular swelling of 4 months' duration. The clinical findings were highly suspicious for malignancy. A fine needle aspiration biopsy was performed. Three preliminary differential diagnoses were offered: mucoepidermoid carcinoma of the submandibular salivary gland, squamous cell carcinomatous deposit in a submandibular lymph node and calcifying odontogenic tumor. Computed tomography demonstrated no bony lesion. No primary site of squamous cell carcinoma could be identified. An excisional biopsy of the swelling was performed, and the histologic diagnosis of pilomatrixoma was made. CONCLUSION: The cytologic presentation of pilomatrixoma of the right submandibular region can masquerade as that of a malignant tumor, in this case mucoepidermoid carcinoma, squamous cell carcinoma or odontogenic tumor. This case delineates the cytomorphologic features of pilomatrixoma that may mimic carcinoma.     

Cytologic findings in peritoneal washings associated with benign gynecologic disease

In order to define the problems in the interpretation of peritoneal washing cytology specimens, 149 benign cases were examined retrospectively and the cytologies compared with the correlating histologies. There were problems in the cytologic interpretation on blind review in 18 cases (12.1%). Difficulties in interpretation of peritoneal washing cytology included conditions associated with (1) mesothelial reactions and adhesion formation, (2) rupture of cystic structures, (3) fallopian tube epithelium and (4) combinations of these factors. It is anticipated that familiarity with these problems will enhance accuracy in peritoneal washing cytology, particularly in those cases in which a malignancy is present but has not penetrated into the peritoneal cavity.     

DNA ploidy in seminal vesicle cells. A potential diagnostic pitfall in urine cytology

OBJECTIVE: To verify that abnormal DNA ploidy in urine cytology can occasionally be attributed to contamination by seminal vesicle cells. STUDY DESIGN: In the first part of this study, we analyzed the DNA content of six urine cytology specimens containing seminal vesicle cells. In the second part, we evaluated 21 Feulgen-stained prostate core biopsies containing seminal vesicle-type epithelium using a CAS-200 system. DNA index, proliferative activity (S + G2M) and degree of hyperploidy (> 5C) were determined in each case. RESULTS: All six urine cytology specimens were diploid, with all but one containing hyperploid cells (range, 0-16%; mean, 6.3%). Seminal vesicle cells from prostate biopsies showed a broad range of ploidy abnormalities. Ten cases (48%) showed an aneuploid peak, two cases (9%) showed a tetraploid peak, and nine cases (43%) showed only a diploid peak. All but one case showed both an elevation in proliferative activity (mean S + G2M, 24.2%) and some hyperploid cells (mean, > 5C; 4.5%). CONCLUSION: Seminal vesicle cells, although rarely seen in urine cytology, can cause abnormal DNA ploidy measurements. Morphologic criteria remain vital to an accurate cytologic diagnosis.     

Cytological features of chronic follicular cervicitis in liquid-based specimens: a potential diagnostic pitfall

A review of negative split-sample cervical cytology cases revealed five cases reported as chronic follicular cervicitis. These cases showed characteristic morphological features in conventional smears with lymphoid cells, plasma cells and tingible body macrophages smeared across the slides. This contrasts with the presentation of ThinPrep samples (Cytic Corporation, Boxburgh, MA, USA), where cells were observed aggregated in clumps. The different presentation noted in liquid-based samples may require careful microscopic evaluation at high-power magnification.