Leiomyosarcoma of the breast: a difficult diagnosis on fine-needle aspiration biopsy

Leiomyosarcoma of the breast is rarely encountered in fine-needle aspiration (FNA) cytologic material. We report a case of primary leiomyosarcoma of the breast in a 52-yr-old female. Aspiration cytology showed large, dissociated round to spindle cells with abundant vacuolated cytoplasm, pleomorphic nuclei, prominent nucleoli, and occasional intranuclear cytoplasmic invaginations. Mitotic figures, osteoclast-like giant cells, and stromal fragments were identified. A diagnosis of malignant neoplasm representing either a sarcoma, a poorly differentiated carcinoma, or a metaplastic carcinoma was made. The patient underwent a wide excision of the lesion after negative work-up. Histologic examination and immunohistochemical studies established the diagnosis of leiomyosarcoma. This case is presented here because we feel that, although FNA cytology with eventual ancillary studies is a valuable diagnostic tool to evaluate any breast mass, malignant spindle cell neoplasms of the breast still represent a diagnostic challenge for the cytopathologist. Recognition of all cytologic features of leiomyosarcoma may help to formulate a correct diagnosis.     

Fine‐needle aspiration findings of Xp11 translocation renal cell carcinoma metastatic to a hilar lymph node

Xp11 translocation renal cell carcinoma (RCC) is a specific type of renal cell carcinoma recently placed under the “MiT family translocation RCC” at the last 2013 ISUP Vancouver classification of renal neoplasia. This tumor contains variable proportions of clear cells and could easily mimic papillary RCC, clear cell type, and clear cell papillary RCC. Given the small number of published cytologic findings of this tumor, it could easily present as a diagnostic pitfall. We describe a case of a 23‐year‐old man with a history of prior nephrectomy who presented with multiple mediastinal lymphadenopathies on imaging surveillance follow‐up. Fine‐needle aspiration of the lymph node showed tumor cells with voluminous clear to eosinophilic cytoplasm, well‐defined cell borders and hyperchromatic nuclei arranged in papillary architecture. Review of the prior nephrectomy specimen showed papillary cores surrounded by cells with voluminous clear to finely granular eosinophilic cytoplasm and distinct cell borders. Immunohistochemical stains performed on the nephrectomy specimen showed tumor positivity for CD10, E‐cadherin, a‐methylacyl coenzyme A racemase, and TFE3 supporting the diagnosis of Xp11 translocation renal cell carcinoma. Although this tumor was initially described predominantly in children, it could also occur in adults, as seen in this case. Familiarity with the cytologic findings of this tumor, use of immunohistochemical stains, or cytogenetic test to determine the type of gene fusion will be extremely useful in arriving at the correct diagnosis. Diagn. Cytopathol. 2017;45:456–462. © 2017 Wiley Periodicals, Inc.     

Pseudoglandular pattern of basaloid cells in pilomatrixoma in the needle aspiration cytology: a case report

A varied cytomorphology of pilomatrixoma often results in diagnostic dilemma. Here, we report a case of pilomatrixoma that presented with prominent gland like arrangement of basaloid cells on cytologic smears causing diagnostic problem. Clinical diagnosis in the present case was cervical lymphadenitis and the cytologic smears showed a strikingly varied morphology with few loose clusters of basaloid cells exhibiting pseudoglandular pattern. A possibility of metastatic carcinoma was considered. However, following histopathologic diagnosis of pilomatrixoma, when cytologic smears were reviewed, it was realized that the ghost cells were overlooked as anucleate squames. Our case highlights the importance of careful clinical and cytologic interpretation of pilomatrixoma. Awareness of the cytomorphologic characteristics of ghost cells and their identification in cytologic smears is highly criticalfor an accurate diagnosis. A prominent basaloid cell component of pilomatrixoma with a pseudoglandular pattern, which has not been described earlier, may easily lead to a false positive diagnosis.     

Hepatic epithelioid angiomyolipoma with trabecular growth pattern: a mimic of hepatocellular carcinoma on fine needle aspiration cytology

Epithelioid angiomyolipomas (AMLs) of the liver are rare tumors with imaging and cytologic features overlapping with those of hepatocellular carcinomas. We report the fine needle aspiration and core biopsy findings of an epithelioid AML in the right hepatic lobe of a 32-year-old female with tuberous sclerosis. She had undergone renal transplantation 8 years previously after bilateral nephrectomy for renal AMLs and a 3-cm chromophobe renal cell carcinoma. Hepatocellular carcinoma was suspected during the initial cytologic and histologic examination based on the presence of numerous large polygonal cells with ample finely vacuolated or granular cytoplasm, low nucleocytoplasmic ratio, and mild nuclear pleomorphism in the smears, as well as a distinctive trabecular histologic pattern in the core biopsies. Immunoperoxidase stains showed that the neoplastic cells were negative for cytokeratins and positive for HMB45, Melan-A, and smooth muscle actin, establishing the diagnosis of epithelioid AML. To determine the distinguishing cytomorphologic features between epithelioid AML and HCC, we have compared the cytologic features of 15 cases of hepatic AML reported in the literature, including the present case, to the FNA cytologic findings of 38 consecutive cases of HCC diagnosed at out institution.     

Diagnostic utility of intracytoplasmic lumen and transgressing vessels in evaluation of Hürthle cell lesions by fine-needle aspiration

INTRODUCTION: Recent abstracts have emphasized the importance of recognizing intracytoplasmic lumen and transgressing vessels as useful criteria enabling distinction between Hürthle cells encountered in neoplastic and nonneoplastic thyroid aspirates. The purpose of this retrospective study was to evaluate if application of these criteria improves specificity and sensitivity of cytologic diagnosis of true Hürthle cell neoplasms. MATERIALS AND METHODS: We retrospectively reviewed 30 fine-needle aspirates of thyroid with cytologic diagnosis of Hürthle cell neoplasms (13 cases) and nonneoplastic thyroid with prominent Hürthle cells (17 cases). All cases were evaluated for the presence of intracytoplasmic lumen and transgressing vessels and were reclassified as neoplastic or nonneoplastic based on the presence or absence of 1 or both of these criteria. Surgical follow-up was available in all cases. RESULTS: Surgical follow-up in 13 cases of Hürthle cell neoplasms revealed Hürthle cell carcinoma (3 cases), Hürthle cell adenoma (6 cases), and Hashimoto's thyroiditis (4 cases). Seventeen cases with nonneoplastic diagnosis revealed Hürthle cell carcinoma (1 case), Hashimoto's thyroiditis (12 cases), and nodular goiter (4 cases). After application of the previously mentioned cytologic criteria, the cytologic diagnoses were reclassified as Hürthle cell neoplasms (13 cases) and nonneoplastic thyroid (17 cases). The true sensitivity of the test before and after the application of the criteria was 90% and 100%, respectively. The true specificity before and after the application of the cytologic criteria was 65% and 85%, respectively. CONCLUSIONS: Intracytoplasmic lumen and transgressing vessels are helpful features in distinguishing neoplastic and nonneoplastic Hürthle cell thyroid lesions. Use of these criteria may improve the specificity and sensitivity of the cytologic diagnosis.     

Fine needle aspiration cytology of insular carcinoma of thyroid

Poorly differentiated (insular) thyroid carcinoma is defined as a thyroglobulin-producing non-follicular non-papillary thyroid carcinoma, having an intermediate behavior between well-differentiated and anaplastic carcinomas. FNAC is widely used as aid for workup of thyroid gland lesion. However, scant information is available in the literature about cytologic findings of this rare entity. Ten cases of surgically resected insular carcinoma with a corresponding cytology were selected. The cytologic smears and histological sections were reviewed for presence of cytomorphologic features including cellularity, predominant cytoarchitectural pattern, additional cytologic co-patters pattern, cell size, cell shape, nuclear pleomorphism, nuclear/cytoplasmic (N/C) ratio, chromatin pattern, amount of cytoplasm, mitotic figures, colloid, background debris, nuclear grooves, and intranuclear pseudoinclusions. In all the cases, the cells were arranged predominantly in solid clusters. Focal microfollicular pattern was identified in five cases of which three cases showed presence of inspissated colloid within the follicles. Singly scattered malignant cells and bare nuclei were seen in all cases. Cells were monomorphic, round with high N/C ratio, finely granular chromatin and inconspicuous nucleoli. Background showed presence of cellular debris in two cases. Mitotic figures were obvious and atypical mitosis was also identified. Cellular smears composed of monomorphic population of small cells arranged in large clusters and sheets with high N/C ratio and high mitosis suggest the possibility of insular carcinoma. Background cellular debris/necrosis also supports the diagnosis. Cell block preparation in these cases may be of additional help in accurate diagnosis.     

Fine-needle aspiration cytology of a metastatic Merkel-cell carcinoma

The cytologic features of Merkel-cell carcinoma metastatic to inguinal lymph nodes are described. The primary tumor was in the buttocks. The cytologic smears from the inguinal lymph node were highly cellular, with small to medium-sized cells in a predominantly discohesive or single-cell pattern, as well as large clusters surrounding segments of capillary-sized blood vessels. The nuclei were uniform, round to oval, with delicate nuclear membranes. The chromatin pattern was fine and "powdery" with multiple small micronucleoli. The cytoplasm was very scanty. Intermediate filament "buttons" were abundant. Rosette formation was very rare. Frequent mitotic figures and individual cell necrosis were observed. These features are helpful in the differential diagnosis from other small-cell tumors that may involve the skin.     

Fine-needle aspiration biopsy of breast adenomyoepithelioma: A potential false positive pitfall and presence of intranuclear cytoplasmic inclusions

Cytologic diagnosis of adenomyoepithelioma can be very challenging. We report fine needle aspiration cytology (FNAC) findings of a benign adenomyoepithelioma. The cytologic features are characterized by hypercellularity and the presence of numerous atypical dispersed cells with epithelioid morphology and intact cytoplasm. The nuclei showed stippled chromatin, irregular nuclear membrane, and prominent eosinophilic nucleoli. No necrosis or mitoses were seen. The presence of naked nuclei, and extensive intranuclear cytoplasmic inclusions were identified and raised the possibility of adenomyoepithelioma. Immunohistochemically, the atypical cells showed strong positivity for myosin heavy chain, p63, and CK5/6, while the epithelial cells reacted with estrogen receptors. This immunophenotypic pattern supports the myoepithelial origin of the atypical cell proliferation and favors the diagnosis of benign adenomyoepithelioma. However, biopsy was recommended to exclude malignancy. Histologically, the tumor showed prominent myoepithelial cells with significant atypia, intranuclear cytoplasmic inclusions, and dense cytoplasm. No evidence of malignancy was identified. In conclusion, we report a case of adenomyoepithelioma with a significant cytological atypia that may result in confusion with malignant breast tumors. The presence of intranuclear cytoplasmic inclusions, naked nuclei, and expression of myoepithelial markers should provide clues to the right diagnosis and benign nature of this lesion. Cytopathologists should be familiarized with this entity to avoid a misdiagnosis of carcinoma. Diagn. Cytopathol. 2012. © 2011 Wiley Periodicals, Inc.     

Cytologic diagnosis of adenoid cystic carcinoma of salivary glands.

The cytomorphologic features in fine-needle aspiration (FNA) biopsies from 31 primary and 33 recurrent adenoid cystic carcinomas (ACC) were investigated. The correct FNA diagnosis was established in 24 of 31 primary ACC (77%). The diagnostic clue in aspirates from ACC are large globules of extracellular matrix, partially surrounded by basaloid tumor cells. In FNAs with predominance of basaloid tumor cells, but lacking characteristic globules, all other benign and malignant salivary gland tumors of epithelial-myoepithelial differentiation should be considered in the cytologic diagnosis. Pleomorphic adenoma is most frequently confused with ACC, and therefore, the cytologic findings in FNAs from 50 pleomorphic adenomas were compared with those diagnosed as ACC. Furthermore, rare neoplasms of salivary glands with epithelial-myoepithelial cell differentiation, including basal-cell adenoma and carcinoma, epithelial-myoepithelial carcinoma, and polymorphous low-grade adenocarcinoma, as well as some nonsalivary gland neoplasms presenting an adenoid cystic pattern, must be considered. The cytologic features of these entities are discussed in detail with respect to the cytologic diagnostic criteria of ACC.     

A simple method for estrogen receptor antigen preservation in cytologic specimens containing breast carcinoma cells

We report a modified method to prepare cytologic specimens for the evaluation of estrogen receptors by immunocytochemistry. Cytologic samples were obtained by needle aspiration of tumor masses (nine patients) and body cavity fluids (nine patients). The cytologic material was divided, and slides for immunostaining were prepared according to two different techniques: (1) fixation of cells in suspension (modified method); and (2) fixation of cells adherent to slides (standard method). The results after immunostaining demonstrated that the number of cells adhering to slides prepared according to the modified method was greatly increased as compared with the number of cells remaining attached to slides prepared according to the standard method. There was no loss of cell groups or aggregates using the modified method. The antigenicity of estrophilin and the cell morphology were well-preserved for up to 30 days. With this modified method, cytologic samples may be stored and conveniently processed in batches, thereby improving the utilization of laboratory resources.     

A correlative cytologic and histologic study of malignant fibrous histiocytoma: an analysis of 40 cases examined by fine-needle aspiration cytology

A correlative cytologic and histologic study of 40 cases of histologically highly pleomorphic malignant fibrous histiocytoma (MFH) is presented. The fine-needle aspiration biopsy was performed preoperatively, and a diagnosis of malignant soft-tissue tumor could be established in all cases. The cytologic and histologic features corresponded well with each other. The two main cell types were mono- and multinucleated, large polymorphic, often bizarre, histiocyte-like cells and atypical fibroblast-like cells. For a correct diagnosis of pleomorphic MFH, it is important to recognize atypical large polymorphic tumor cells showing signs of phagocytosis: prominent cytoplasmic vacuolization, cell debris or even well-preserved cells within the tumor cell cytoplasm. Phagocytic activity was easily demonstrated in air-dried and May-Grünwald Giemsa-stained material. The differential diagnosis of MFH as opposed to other soft-tissue sarcomas and pleomorphic carcinomas is discussed.     

Pelvic washing cytology of ovarian Sertoli-Leydig-cell tumor with retiform pattern: a case report

A Sertoli-Leydig-cell tumor is an exceptionally rare neoplasm. We present the pelvic washing cytomorphology of an ovarian Sertoli-Leydig-cell tumor with a retiform pattern in a 24-yr-old female. The cytologic features in this case were tight tissue fragments composed of small, relatively uniform cells with scanty cytoplasm and small rounded or blunt papillary fragments with hyalinized cores lined with small, mildly atypical cuboidal cells. Differential diagnoses included borderline and well-differentiated papillary serous tumors, clear-cell carcinoma, and collagen balls. Correlation of cytologic findings with histomorphology is crucial for correct interpretation of pelvic washings in cases of Sertoli-Leydig-cell tumors.     

Somatic but not germline mutation of the APC gene in a case of cribriform-morular variant of papillary thyroid carcinoma

We report a case of cribriform-morular variant (C-MV) of papillary thyroid carcinoma (PTC) in a 27-year-old woman. In addition to conventional cytologic features of typical PTC, the fine-needle aspirate showed numerous epithelial cells with abundant, eosinophilic, very elongated cytoplasm. Microscopically, the tumor was encapsulated and highly cellular and exhibited a mixture of cribriform, follicular, papillary, trabecular, solid, and spindle cell patterns of growth, with morular foci showing peculiar nuclear clearing (biotin-rich nuclei). The cells were cuboidal or tall, with frequent nuclear pseudostratification and abundant eosinophilic cytoplasm. The nuclei were usually hyperchromatic, with grooving, pallor, and pseudoinclusions. Angioinvasion and foci of capsular invasion were observed. Immunohistochemically, the neoplastic cells showed reactivity for thyroglobulin, epithelial membrane antigen, low- and high-molecular-weight cytokeratins, vimentin, neuron-specific enolase, CD15, estrogen and progesterone receptors, and bcl-2 protein. Molecular genetic analysis of the APC gene revealed a mutation in exon 15 at codon 1309 in tumoral tissue but not in peripheral lymphocytes. These findings support a relationship between the morphologic pattern of the C-MV of PTC and the APC gene and the existence of this variant as a sporadic counterpart of familial adenomatous polyposis-associated thyroid carcinoma.     

Fine-needle aspiration cytology and differential diagnoses of fibrolamellar hepatocellular carcinoma metastatic to the mediastinum: case report

We report a case of fibrolamellar hepatocellular carcinoma (FL-HCC) that metastasized to the posterior mediastinum. The diagnosis was made on fine-needle aspiration biopsy (FNAB). The cytologic features were characterized by the presence of large, dishesive, polygonal cells with granular cytoplasm and well-defined cell outlines resembling oncocytes. Groups of neoplastic hepatocytes containing bile pigment were also noted. The diagnosis of FL-HCC in a metastatic site can pose diagnostic challenges on FNAB. The cytologic features overlap with a variety of tumors that have oncocytic features and also with melanoma and paraganglioma. Recognition of specific cytologic features of FL-HCC can facilitate accurate diagnosis in a metastatic site. The cytologic findings and differential diagnoses of FL-HCC that metastasized to the posterior mediastinum are discussed.     

Cytologic features of insular carcinoma of the thyroid: a case report

Fine-needle aspiration of the thyroid has been accepted as one of the initial diagnostic tools in the evaluation of thyroid nodules. As its use becomes more widespread, the demand for more precise diagnosis has increased. The histopathology of insular carcinoma of the thyroid is now well recognized. However, the cytologic diagnostic criteria are not well established. The reported series have been small (4-6 cases), which is not surprising because of the rarity of this tumor. They consist of retrospective reviews of the aspirates (after the histologic diagnosis had been made from the thyroidectomy specimens). Also, the case reports do not provide uniform cytologic criteria; this could be due to limited sampling of these tumors (which are usually large). A cytologic diagnosis of insular carcinoma can be suggested if multiple samples of a thyroidal mass are markedly cellular, with a cytologic pattern reminiscent of a follicular variant of papillary carcinoma. However, the follicular cells are arranged predominantly in rosettes, their nuclei appear more monotonous, some "intranuclear cytoplasmic pseudoinclusions" are seen, and there is an occasional large cell with a pleomorphic nucleus.     

Small cell mesothelioma: A rare entity and diagnostic pitfall mimicking small cell lung carcinoma on fine‐needle aspiration

Small cell mesothelioma (SCM) is an extremely rare variant of epithelioid mesothelioma that can be mistaken for other forms of small round blue cell tumors, particularly small cell lung carcinoma (SCLC). Here, we describe a fine‐needle aspiration (FNA) from a pleural lesion in a 75‐year‐old man with a history of known asbestos exposure. The FNA revealed cohesive clusters of uniform small round blue cells with high nuclear‐to‐cytoplasmic ratio, finely powdery chromatin, small inconspicuous nucleoli, and scant amount of cytoplasm. Mitoses were infrequent and nuclear molding was absent. Immunochemical profile supported a mesothelial origin, which was later confirmed by pleurectomy with a diagnosis of SCM. This report demonstrates the difficulties in cytologic evaluation of lung FNAs in differentiating SCM from SCLC or other small round blue cell tumors. As therapy differs for SCM, early recognition of the cytologic features is essential in making the correct diagnosis needed for appropriate clinical management. Diagn. Cytopathol. 2016;44:526–529. © 2016 Wiley Periodicals, Inc.     

Exfoliative cytology of primary poorly differentiated (small-cell) neuroendocrine carcinoma of the uterine cervix in ThinPrep material: a case report

Poorly differentiated neuroendocrine (small-cell) carcinoma of cervical origin is a rare neoplasm that frequently metastasizes. Although the cytologic features have been described for conventional cervical smears, we know of no reports of its appearance in ThinPrep (TP) material. Therefore, we present a TP case of primary, small-cell carcinoma arising in a 46-yr-old female, confirmed by histologic and immunohistochemical analysis. Similar to conventional smears, the neoplastic cells occurred either individually or in small clusters. The cells were relatively monomorphic, with stippled chromatin and minimal amounts of cytoplasm. Unlike conventional smears, nuclear molding was not prominent (although overlap was observed), and nuclear smearing was not identified. The features are compared to TP cases of squamous-cell carcinoma, small-cell type, and endometrioid adenocarcinoma, which are close mimics of small-cell carcinoma. We conclude that correct diagnosis of small-cell carcinoma in TP is difficult, requiring a high degree of suspicion and immunohistochemical confirmation.     

Cytomorphology of small-cell (neuroendocrine) carcinoma on ThinPrep cytology as compared to conventional smears

Small-cell (neuroendocrine) carcinoma of the female genital tract is an uncommon, aggressive neoplasm that occurs most commonly in the cervix and rarely in the vagina. Although the cytologic findings have been reported on conventional smears, the cytologic diagnosis of primary vaginal small-cell carcinoma on ThinPrep material has not been previously reported. We present a case of a 46-yr-old woman who underwent cervical/vaginal biopsies as a result of abnormal cells seen on the ThinPrep Pap Test. Small to medium-sized cells with scant cytoplasm were present singly and in loose, cohesive clusters. Nuclear molding was noted in a few cellular groups. The differential diagnosis included a high-grade squamous intraepithelial lesion, small-cell (neuroendocrine) carcinoma, endometrial adenocarcinoma, and lymphoma. Subsequent tissue biopsies with immunohistochemical staining confirmed a diagnosis of small-cell carcinoma of the vagina. The cytologic features of small-cell (neuroendocrine) carcinoma on slides prepared by the ThinPrep Pap Test are discussed and compared to those on conventional cervicovaginal smears.     

Aspiration cytology of papillary cystic neoplasm of the pancreas

The authors present a case of papillary and cystic neoplasm of the pancreas (PCN) in which fine-needle aspiration was performed intraoperatively. Only a few reports of fine-needle aspiration of this rare tumor have been published. The features most helpful in reaching a diagnosis of PCN were a monotonous population of tumor cells, round to oval bland-appearing nuclei, scanty to moderate ill-defined cytoplasm, and the presence of numerous capillaries. Despite the lack of branching papillary clusters described in previous reports, it was possible to suggest the correct diagnosis by identifying these other characteristic features. In addition, estrogen and progesterone receptor levels were measured and found to be negligible. A review of the literature with emphasis on cytologic features also is presented.     

Multiple loss of heterozygosity without K-ras mutation identified by molecular analysis on fine-needle aspiration cytology specimen of acinar cell carcinoma of pancreas

Fine-needle aspiration diagnosis of pancreatic acinar cell carcinoma (PAC) is challenging. Typically, the cytologic findings in PAC are described as a cellular population of loosely cohesive clusters and single neoplastic cells. The individual cells have granular cytoplasm, uniform nuclei, a fine chromatin pattern, and occasional prominent nucleoli. These features are suggestive of PAC but not diagnostic. We illustrate a case in which the combination of cytopathologic findings, clinical information, and molecular analysis enabled us to arrive at the diagnosis of PAC. Although the cytomorphologic features alone were not specific, the presence of a markedly elevated serum lipase level, cutaneous lesions of fat necrosis, and loss of heterozygosity at 1p, 5q25 at the APC locus, 9p21 at the p16 locus, and 17p13 at the p53 locus were essential in excluding the main differential diagnostic entities including pancreatic ductal carcinoma, pancreatic endocrine tumor, and pancreatoblastoma.