Cytologic differential diagnosis of papillary pattern in breast aspirates: correlation with histology.

Papillary neoplasms, fibroadenoma, fibrocystic change, low-grade ductal carcinoma, and apocrine carcinoma are among "gray zone" lesions in breast cytology. They often have cellular smears with a papillary or pseudopapillary pattern. To better define cytologic criteria useful in distinguishing these entities, we correlated them with histology. Papanicolaou and giemsa stained smears from 33 aspirates and their corresponding histology were reviewed. Of these, 28 had an initial cytologic diagnosis or suspicion of papillary neoplasm, while five cases were not diagnosed cytologically as papillary but the histologic diagnosis was a papillary neoplasm. Cytologic features evaluated included cellularity, architecture, apocrine/single/columnar cells, nuclear atypia, intranuclear inclusions, calcifications, background, myoepithelial cells, and bipolar, naked nuclei. Discriminating cytologic features grouped by final histologic diagnosis were as follows: Papillary neoplasm (14 cases): Hemorrhagic/cystic background, 3-dimensional papillary clusters, columnar cells, and fibrovascular cores. Myoepithelial cells within clusters and background naked, bipolar nuclei were inconspicuous. Fibroadenoma (4 cases): Two-dimensional branching clusters often with folding, moderate myoepithelial cells in clusters, moderate to numerous background bipolar nuclei, often forming doublets in smear background, cellular stroma. Ductal carcinoma (11 cases): Papillary ductal carcinoma in situ in 5 of 11 cases, cribriform/tubular architecture in 6 of 11. Absence or paucity of myoepithelial within clusters and background bipolar nuclei was noted. Fibrocystic change (4 cases): Two-dimensional clusters, moderate myoepithelial cells within clusters, and moderate bipolar nuclei in the background. The presence and quantity of myoepithelial cells, bipolar naked nuclei in the background, and ductal cell architecture were the only consistently useful cytologic features in distinguishing breast lesions with a papillary pattern. Ann Diagn Pathol 5:34-42, 2001.

Thyroid plasmacytoma mimicking medullary carcinoma: a potential pitfall in aspiration cytology.

Extramedullary plasmacytoma (EMP), a malignant neoplasm of the soft tissues composed of plasma cells, may occur either as a solitary plasma-cell tumor (primary EMP) or as a manifestation of multiple myeloma (secondary EMP). We report on the aspiration cytology findings of an intriguing case of EMP of the thyroid that was initially misinterpreted as medullary carcinoma on clinical and cytologic examination. A major contributing cause for the cytologic misinterpretation was the presence of amyloid in the aspirate and the clinical impression of a "thyroid mass." Based on this experience, we suggest that EMP should be considered in the differential diagnosis of a neck mass that yields discohesive cells associated with amyloid/amyloid-like material. Clinical correlation and immunocytochemistry are crucial in avoiding pitfalls in this situation.

Evaluation of histochemical methods for the detection of intracytoplasmic mucin in serous effusions.

We have studied 25 serous effusions containing definitive morphologic evidence of adenocarcinoma to evaluate the ability of two mucin stains (Mayer's mucicarmine, D-PAS) to detect intracytoplasmic mucin in both cytologic (cytospin) and corresponding histological (cell block) preparations. Mucicarmine stain was positive in six of 25 (24%) cytospins and 13 of 25 (52%) cell blocks. D-PAS was positive in 19 of 25 (76%) cytospins and 20 of 25 (80%) cell blocks. Eight cases were identified which showed mucicarmine positivity in the cell block but not the corresponding cytospin; prolonging incubation time resulted in a positive mucicarmine in cytospin preparations for seven of these cases. We conclude that: (i) D-PAS is a more sensitive stain for the detection of intracytoplasmic mucin in all preparations; (ii) mucicarmine shows preferential staining for cell blocks; (iii) alterations in the staining protocol may permit mucin detection by mucicarmine staining in cytologic preparations in a significant number of cases.

Cytomorphologic appearance of follicular dendritic-cell tumor: a case report.

Follicular dendritic-cell (FDC) tumors are extremely rare, recently described neoplasms. Only one report currently exists in the cytology literature. We present a case of FDC tumor with emphasis on its cytomorphology and its correlation with histology, immunohistochemistry, and ultrastructure.

Metaplastic breast carcinoma metastatic to the lung mimicking a primary chondroid lesion: report of a case with cytohistologic correlation.

This case study illustrates the unusual morphologic findings of a metastatic breast carcinoma to the lung. The tumor showed chondromatous differentiation and mimicked a primary chondroid lesion of the lung on fine-needle aspiration and needle core biopsy. The patient was a 59-year-old woman with a previous history of stage II carcinoma of the breast, which had been reported as "poorly differentiated, infiltrating ductal carcinoma," with two of 13 axillary lymph nodes showing metastatic ductal carcinoma. The pathology report received from the outside institution contained no mention of metaplastic components, and because the new pulmonary lesion was a peripherally located, well-circumscribed mass found incidentally on abdominal computed tomography scan in the lower lung field cuts, pulmonary chondroid hamartoma was initially postulated as a preliminary diagnosis. However, on review of the outside glass slide material from a prior lumpectomy, chondromatous differentiation was identified and a final diagnosis of metaplastic carcinoma of the breast with pulmonary metastasis was made. To the best of our knowledge, this is the only reported case of a metastasis of metaplastic breast carcinoma initially identified from fine-needle aspiration biopsy. The importance of recognizing and reporting metaplastic elements in primary breast tumors is discussed, and the value of direct morphologic comparison of cytologic material to prior histology is emphasized.

Follow-up of atypical glandular cells in cervical-endocervical smears.

Atypical glandular cells of undetermined significance (AGUS) is a diagnostic category of the Bethesda system encompassing glandular-type cells that show either endometrial or endocervical differentiation and display greater atypia than expected for a reactive process but do not meet the criteria for invasive adenocarcinoma. We investigated AGUS in a follow-up study of cervical-endocervical smears with either histology or repeat cytology follow-up. From the cytology files at Northwestern Memorial Hospital over a 4-year period, 136 cervical-endocervical smears were diagnosed with AGUS, which were further subdivided into atypical glandular cells, unqualified (AGC-U); atypical glandular cells, favor reactive (AGC-FR); or atypical glandular cells, favor neoplasia (AGC-FN). Of 96 cases with either histologic or cytologic (cervical-endocervical smear) follow-up, 39 cases of AGC-U had a variety of diagnoses on follow-up, with mostly benign entities in 72% and squamous intraepithelial lesions in 28%. Follow-up of the 36 cases of AGC-FR also demonstrated mostly benign entities (82%) and five cases of squamous intraepithelial lesions. The largest number of premalignant and malignant diagnoses (48%) was found during follow-up of patients with an initial diagnosis of AGC-FN, including the only two cases of adenocarcinoma in situ in our study. In conclusion, our study confirms that AGUS encompasses a wide spectrum of diagnoses, most of which prove to be benign. Subclassification of these cases into "favor reactive" and "favor neoplasia" was found to be helpful in predicting the follow-up status of these patients. However, the small but distinctive percentage of preneoplastic and neoplastic diagnoses seen on follow-up warrant further diagnostic procedures and/or close monitoring in patients with this diagnosis.

The immediate postconization endocervical smear: evaluation of its utility in the detection of residual dysplasia.

OBJECTIVE: To determine the diagnostic value of obtaining an endocervical smear for cytologic examination immediately following cervical conization (by either the loop electrosurgical excision procedure or large loop excision of the transformation zone) in the detection of residual squamous dysplasia. STUDY DESIGN: Thirty-eight cases were identified in which cervical conization was immediately followed by endocervical sampling (most commonly using a brush) and smear. RESULTS: Twenty-one of the 38 postconization endocervical smears (55%) were either unsatisfactory or sub-optimal for evaluation due to cellular distortion (i.e., cautery artifact), degeneration or obscuring blood. Histologic in evaluation showed negative endocervical margins in 32 cases (84%) and positive endocervical margins in 6 cases (16%), including both low and high grade squamous intraepithelial lesions. The endocervical smears in the 32 cases with a negative surgical margin did not demonstrate evidence of dysplasia. However, in the six cases with histologically positive margins, postconization endocervical smears also failed to identify any evidence of dysplasia. CONCLUSION: Immediate postconization endocervical smears do not appear to be useful for the detection of residual disease in patients undergoing conization for squamous dysplasia of the cervix.

Tumor cell (dys)cohesion as a prognostic factor in aspirate smears of breast carcinoma.

As the ability of fine-needle aspiration biopsy to separate benign from malignant lesions approaches its limits, the potential to provide additional prognostic information based on these same specimens has received increasing attention. An area we have pursued is based on the recognized finding that many neoplastic cells exhibit altered expression of intercellular adhesion molecules. In this study, we evaluated a large number of preoperative fine-needle aspiration smears (83 cases) of histologically proven primary breast ductal carcinoma in an attempt to correlate the degree of cellular dyscohesion in the aspirate with the presence of local (ipsilateral axillary lymph node) metastases. We found that although the smear pattern of primary tumors greater than 3 cm showed no correlation with the presence of positive axillary nodes, the degree of tumor cell dyscohesion of tumors less than 3 cm (60 cases) as seen in aspirate smears did correlate with the presence of regional metastases. Poorly cohesive primary tumors were always associated with local metastases (4 of 4 cases, 100%) compared with those of intermediate (15 of 37 cases positive, 40%) and high cohesion (5 of 19 cases positive, 26%). Thus, we believe the evaluation of tumor cell (dys)cohesion in cytologic smears shows great promise as a simple, cost-effective technique to predict the biologic behavior of breast carcinoma.

Thymic epithelial cells as a diagnostic pitfall in the fine-needle aspiration diagnosis of primary mediastinal lymphoma.

The cytologic diagnosis of primary mediastinal lesions is challenging due to the large number of lesions which may arise (i.e., lymphoma, thymoma, germ cell tumor), often with overlapping cytomorphologic features. We present an instructive case of primary mediastinal non-Hodgkin's large-cell lymphoma with sclerosis, entrapping thymic epithelium. Preoperative fine-needle aspiration yielded predominantly epithelial fragments and few lymphoid cells leading to the cytologic misdiagnosis of thymoma. The entity of primary mediastinal large-cell lymphoma (LCL) is discussed and correlated with the cytologic features seen. In addition, histologic sections from 15 additional cases of primary mediastinal LCL were evaluated to determine the frequency with which significant numbers of epithelial fragments may be observed.