Riedel thyroiditis: Fine needle aspiration findings of a rare entity

Riedel thyroiditis is a rare fibrosing disorder characterized by extension of the fibroinflammatory process beyond the thyroid capsule. Due to the nature of this lesion, fine‐needle aspiration often yields scant material and may be interpreted as non‐diagnostic. In this report, we describe cytologic features that allow the cytopathologist to favor a diagnosis of Riedel thyroiditis, thereby guiding appropriate further work‐up and management. Diagn. Cytopathol. 2015;43:747–750. © 2015 Wiley Periodicals, Inc.     

Chondrosarcoma of the hyoid bone: A diagnostic pitfall in the submandibular region

Chondrosarcoma is a malignant chondroid matrix‐producing neoplasm which usually presents in the bones of the pelvis, followed by the proximal femur, proximal humerus, distal femur and ribs. The occurrence of this lesion in the hyoid bone is exceedingly rare, with only a few reported cases, and its diagnosis by fine‐needle aspiration cytology (FNAC) in this particular location, to our knowledge, has never been addressed. Furthermore, the sampling of chondroid matrix at this site can pose a diagnostic dilemma with other lesions of the submandibular region. This report describes the clinical, radiologic and cytologic features on FNAC of a chondrosarcoma of the hyoid bone, emphasizing the diagnostic pitfalls of this entity and expanding the cytologic differential diagnosis of tumors of the submandibular region. Diagn. Cytopathol. 2015;43:933–936. © 2015 Wiley Periodicals, Inc.     

Cytology of low‐grade cribriform cystadenocarcinoma in salivary glands: Cytological and immunohistochemical distinctions from other salivary gland neoplasms

Low‐grade cribriform cystadenocarcinoma of the parotid gland is rare malignancy that is classified as a variant of cystadenocarcinoma. In routine cytologic slides from fine‐needle aspiration of a parotid gland, we found several pseudopapillary clusters comprising mucus‐producing cells. They included a few tumor cells having three‐dimensional nuclear atypia and slight hyperchromatism, although most of the tumor cells showed bland nuclei. Our initial cytological diagnosis was: “Indeterminate. Uncertain whether cystadenocarcinoma or cystadenoma.” The subsequent histological diagnosis was low‐grade cribriform cystadenocarcinoma. Immunohistochemical staining showed diffuse and strong reactivity for S‐100; tumor nests that were rimmed by p63⁺ cells, which suggests intraductal proliferation. Here, we report cytomorphological findings of this case, and discuss cytological and immunohistochemical distinctions between low‐grade cribriform cystadenocarcinoma and other salivary gland tumors, including a review of the literature. Diagn. Cytopathol. 2016;44:241–245. © 2015 Wiley Periodicals, Inc.     

Aspiration cytology of primary thyroid paraganglioma

Thyroid paragangliomas are extremely rare tumors arising from the inferior laryngeal paraganglia. Most patients are female and present as asymptomatic thyroid nodule. Diagnosing thyroid paraganglioma can be difficult on fine‐needle aspiration (FNA) since it could be misdiagnosed as medullary thyroid carcinoma, calcitonin‐negative neuroendocrine tumor of the thyroid gland (CNNETT), metastatic neuroendocrine tumor, and intrathyroid parathyroid proliferation. We describe the cytologic features and immunohistochemical staining pattern of thyroid paraganglioma from a 60‐year‐old woman with a gradually enlarging neck mass for several months. An ultrasound guided fine‐needle aspiration was performed which revealed epithelioid, plasmacytoid to occasionally spindle‐shaped cells with ovoid to elongated nuclei, fine chromatin pattern and inconspicuous nucleoli. The cells were arranged singly, in sheets, and focally in acinar pattern. Occasional nuclear overlapping, crush artifact, and binucleated cells were identified. Neither colloid nor amyloid was seen. Immunohistochemical stains performed on the cell block showed the tumor cells were positive for neuroendocrine markers and negative for cytokeratin (AE1/AE3), calcitonin, CEA, thyroglobulin, and TTF‐1. There were rare S‐100 positive cells. Given the difference in management of paragangliomas compared to its cytology mimics and association with familial cancer syndromes in some cases, awareness of this rare tumor, and use of immunohistochemical stains are critical in arriving at the diagnosis. Diagn. Cytopathol. 2015;43:838–843. © 2015 Wiley Periodicals, Inc.     

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.     

Hyaline matrix in hyalinizing trabecular tumor

Hyalinizing trabecular tumor (HTT) is a rare neoplasm which usually follows an indolent clinical course. The cytologic diagnosis of HTT can be challenging as these neoplasms share cytomorphological features with other thyroid neoplasms and paraganglioma. In fine‐needle aspiration (FNA) smears a diagnosis of papillary thyroid carcinoma (PTC) or suspicion of PTC is often made. Herein we report cytologic findings in two patients with HTT examined by FNA. The key to a correct diagnosis is the recognition of a hyaline and colloid/amyloid‐like material in the background of the smears. Immunocytochemical examination showing aberrant membranous and peripheral cytoplasmic staining for MIB‐1 can help in rendering a correct diagnosis. Diagn. Cytopathol. 2015;43:710–713. © 2014 Wiley Periodicals, Inc.     

“Cannonballs” and psammoma bodies: Unusual cytologic features of metastatic pulmonary small‐cell carcinoma in a pleural effusion

Large three‐dimensional cell aggregates and psammoma bodies are usually encountered in benign serous effusions (mesothelial hyperplasia and endosalpingiosis), mesotheliomas, and metastatic papillary carcinomas. We report a case of pulmonary small‐cell carcinoma occurring in an 88‐year‐old woman that initially presented with a malignant pleural effusion characterized cytologically by a predominance of large three‐dimensional neoplastic cell aggregates (“cannonballs”), associated with rare psammoma bodies. Although the crowded three‐dimensional tumor‐cell aggregates did not allow detailed cytologic examination, the diagnosis of metastatic small‐cell carcinoma could be established noting the characteristic chromatin features of the occasional single neoplastic cells and the characteristic “cell‐in‐cell” and “stack‐of‐coins” arrangements of rare small clusters of neoplastic cells. Immunoperoxidase stains showing positivity of the tumor cells for CD56, synaptophysin, and TTF1 further supported this diagnosis. Endobronchial ultrasound‐guided fine‐needle aspiration of a mediastinal lymph node subsequently confirmed the diagnosis of pulmonary small‐cell carcinoma. Metastatic pulmonary small‐cell carcinoma should be considered in the differential diagnosis of serous effusions showing large three‐dimensional neoplastic cell aggregates and psammoma bodies to prevent a potential diagnostic pitfall. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.     

Fine‐needle aspiration of soft tissue myoepithelioma

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. We describe the cytologic features of a soft tissue myoepithelioma arising in the right lower chest wall in a 65‐year‐old woman. The fine‐needle aspiration (FNA) smears showed round to oval, spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm, and resembled lobular carcinoma of breast. Ultrasound guided core biopsy showed the tumor cells had bland cytologic features, arranged in small cords, nests, and dissociated single cells, with no glandular differentiation or breast tissue seen. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3) and glial fibrillary acidic protein, but were negative for estrogen receptor. Fluorescence in situ hybridization demonstrated the EWSR1 rearrangement, confirming the diagnosis of myoepithelioma. Diagn. Cytopathol. 2016;44:152–155. © 2015 Wiley Periodicals, Inc.     

Pulmonary crystal‐storing histiocytosis diagnosed by computed tomography‐guided fine‐needle aspiration

Crystal‐storing histiocytosis (CSH) is a rare process most often occurring in conjunction with an underlying hematopoietic neoplasm, usually multiple myeloma or low‐grade B‐cell lymphoma. We report the first case of pulmonary CSH diagnosed by fine‐needle aspiration biopsy. A patient with a history of urothelial carcinoma developed a lung nodule, which was evaluated by fine‐needle aspiration biopsy. Cytologic examination revealed macrophages with abundant cytoplasmic crystals diagnostic of CSH. Based on this cytologic interpretation, additional clinical laboratory evaluation was pursued and revealed a previously unknown monoclonal serum protein. CSH must be differentiated from other non‐neoplastic and neoplastic lesions and when diagnosed, should trigger a search for an underlying lymphoproliferative disorder. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.     

Parapharyngeal chordoma: A diagnostic challenge and potential mimic of pleomorphic adenoma on fine‐needle aspiration cytology

Chordomas are rare tumors that are usually located in the sacrococcygeal and sphenooccipital region. Their cytologic diagnosis is rather straightforward when sampled by fine‐needle aspiration (FNA) from these characteristic locations, especially when physalipherous cells are present. However, chordomas may pose difficult diagnostic challenges when encountered in unusual locations, such as the parapharyngeal region. We report the cytologic findings of a recurrent chordoma sampled through transoral FNA from the parapharyngeal space of a 66‐year‐old woman. As the prior history of chordoma was not available during the rapid onsite evaluation, the presence of bland epithelioid nonvacuolated cells and spindle cells intimately admixed with a fibrillary, intensely metachromatic material led to an initial diagnosis of pleomorphic adenoma. Review of the patient's prior pathology specimen and of the Papanicolaou‐stained smears and cellblock sections showing rare multivacuolated (physalipherous) cells led to the correct diagnosis, which was supported by immunoperoxidase stains (cytokeratin AE1/AE3+, S100+, GFAP?). A review of the literature found no previous instances in which chordomas mimicked pleomorphic adenoma on FNA. However, since the two tumors show significant cytomorphologic overlap, including the presence of abundant fibrillary matrix with embedded neoplastic cells and single bland spindle and epithelioid tumor cells with occasional intranuclear pseudoinclusions, we compared their cytologic features. A review of the FNA cytologic features of this case of chordoma and of 17 consecutive cases of pleomorphic adenoma found that the presence of a more abundant, focally vacuolated cytoplasm favors chordoma over pleomorphic adenoma. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.     

Endoscopic ultrasound-guided fine needle aspiration diagnosis of metastatic sex cord tumor with annular tubules: a case report

The cytologic findings of a paratracheal metastasis from a malignant sex cord tumor with annular tubules (SCTATs) diagnosed by endoscopic ultrasound guided fine needle aspiration are described. Cytologic features of SCTATs include the presence of highly cellular aspirates forming simple and complex rosette-like structures around central rounded hyaline material, small nucleoli, and prominent nuclear grooves. These cytologic findings are clearly distinct from the poorly formed rosette-like structures of granulosa-cell tumors and are reminiscent of the low-power appearance of the cribriform variant of adenoid cystic carcinoma. The fine needle aspiration cytologic features of only two other cases have been previously described and, to the best of our knowledge, this is the first case reporting the cytologic diagnosis of a distant metastasis of a SCTATs by endoscopic ultrasound-guided fine needle aspiration. In this case, the distinctive and characteristic cytologic features have allowed the proper diagnosis of a distant metastasis of SCTATs.     

Committee I: Indications for pulmonary cytology sampling methods

The Papanicolaou Society of Cytopathology has developed a set of guidelines for pulmonary cytology including indications for bronchial brushings, washings and endobronchial ultrasound‐guided fine needle aspiration, technical recommendations for cytologic sampling, recommended terminology and classification scheme, recommendations for ancillary testing and recommendations for postcytologic diagnosis management and follow‐up. All recommendation documents are based on the expertise of the authors, extensive literature review and feedback from presentations at national and international conferences. This document selectively presents the results of these discussions. The present document summarizes the recommendations for clinical and imaging evaluation of pulmonary lesions along with the indications for cytologic studies regarding these abnormalities. Preprocedural requirements regarding brushing, washing and needle aspiration procedures are discussed also. Diagn. Cytopathol. 2016;44:1010–1023. © 2016 Wiley Periodicals, Inc.     

Cytologic findings of NUT midline carcinoma in the hilum of the lung

Nuclear protein in testis (NUT) midline carcinoma (NMC) is a clinically lethal malignancy affecting all age group often located in the midline structures such as mediastinum, larynx and nasopharynx. It is characterized by chromosomal translocation between chromosomes 15 and 19 with the formation of chimeric gene BRD‐NUT. We present the cytologic findings of NMC including the immunohistochemical stains performed. The patient is a 34‐year‐old man who presented with 1 month history of dyspnea and interscapular pain followed by nonproductive cough a week before consultation. He was initially diagnosed with pneumonia. Due to progression of symptoms, a chest CT scan was performed revealing a large hilar mass and mediastinal adenopathy. A core biopsy with touch preparations of the hilar mass was performed which revealed cohesive malignant cells with ovoid to elongated nuclei, fine to coarse chromatin pattern, irregular nuclear contour, prominent nucleoli, and scant ill‐defined cytoplasm arranged in sheets and focally pseudoglandular pattern. Although focal nuclear overlapping and crush artifact were identified, karyorrhectic debris and mitotic figures were rare. Squamous differentiation was absent. The core biopsy showed discohesive malignant cells with tumor necrosis. No nuclear molding, glandular or squamous differentiation was identified. The tumor was immunoreactive for p63 and NUT with high Ki‐67 (>80%). The tumor was negative for keratin, lymphoid, myeloid, neuroendocrine markers and S‐100. This case emphasizes that cytologic features of NMC can mimic poorly differentiated, undifferentiated and neuroendocrine carcinomas and the importance of immunohistochemical stains especially NUT monoclonal antibody in arriving at the diagnosis. Diagn. Cytopathol. 2015;43:739–742. © 2015 Wiley Periodicals, Inc.     

Enteropathy‐associated intestinal T‐cell lymphoma in cavitating mesenteric lymph node syndrome: Fine‐needle aspiration contributes to the diagnosis

Cavitating mesenteric lymph node syndrome (CMLNS) is an infrequently reported manifestation of unrecognized/longstanding celiac disease and may be associated with enteropathy‐associated intestinal T‐cell lymphoma and hyposplenism. Unrecognized malignancy and life‐threatening infections can pose a significant risk to patients in cases of delayed diagnosis. Fine‐needle aspiration of the mesenteric lesions may contribute significantly to the correct diagnosis and can expedite patient management. We report on the cytologic characteristics of enteropathy‐associated intestinal T‐cell lymphoma first detected in a cyst fluid specimen obtained from a patient with cavitating mesenteric lesions. Image‐guided fine‐needle aspiration resulted in chylous fluid that contained a lymphoid cell population with neoplastic morphology and abnormal immunophenotype. Further work‐up led to the diagnosis of enteropathy‐associated intestinal T‐cell lymphoma with bone marrow involvement. Cytologic assessment of the cyst fluid is an important part of the diagnostic cascade in patients with CMLNS to exclude clinically occult lymphoma. Diagn. Cytopathol. 2015;43:125–130. © 2014 Wiley Periodicals, Inc.     

Pulmonary non‐Hodgkin's lymphoma (NHL) of diffuse large B‐cell type with simultaneous humeral involvement in a young lady: An uncommon presentation with cytologic implications

A bronchogenic carcinoma, almost invariably, presents as a lung mass. Primary pulmonary lymphomas are rare. We report an unusual case of a pulmonary non‐Hodgkin's lymphoma (NHL) with simultaneous involvement of the right humerus in a 37 year old lady. Bronchial lavage smears showed atypical cells with irregular nuclear membranes raising a suspicion of a hematolymphoid tumor, over a small cell carcinoma that was the closest differential diagnosis. Biopsy from the lung mass and from the lesion in the humerus showed an identical malignant round cell tumor with prominent apoptosis. On immunohistochemistry (IHC), tumor cells were diffusely positive for leukocyte common antigen (LCA), CD20 and MIB1 (70%), while negative for cytokeratin (CK), epithelial membrane antigen (EMA) synaptophysin, chromogranin, neuron specific enolase (NSE), CD3, and CD10. Diagnosis of a pulmonary NHL of diffuse large B‐cell type with involvement of the humerus was formed. The case is presented to create an index of suspicion for the possibility of a NHL on respiratory samples, while dealing with small round cells with irregular nuclear membranes. IHC is necessary to confirm he diagnosis. A simultaneous association in the humerus in our case makes it unusual. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.     

Fine‐needle aspiration cytology of type A thymoma with adenoid cystic pattern: A case report with emphasis on peculiar hyaline globules in cytologic smear

Here we report a case of type A thymoma with adenoid cystic pattern, which extended to the lower anterior neck and clinically mimicked a nontoxic thyroid goiter. The cytologic smears of fine‐needle aspiration showed cohesive fragments of short spindle cells with finely granular chromatin and inconspicuous nucleoli. Scant interspersed lymphocytes were present. On air‐dried Liu stained preparation, there were many magenta‐colored hyaline globules wrapped by spindle tumor cells. The cytomorphologic findings correlated with the adenoid cystic pattern in histology. The cytologic differential diagnosis and the prognostic aspects of type A thymoma were briefly discussed. Diagn. Cytopathol. 2015;43:247–250. © 2014 Wiley Periodicals, Inc.     

Cytopathologic differential diagnosis of low‐grade urothelial carcinoma and reactive urothelial proliferation in bladder washings: a logistic regression analysis

Conventional cytomorphologic assessment is the first step to establish an accurate diagnosis in urinary cytology. In cytologic preparations, the separation of low‐grade urothelial carcinoma (LGUC) from reactive urothelial proliferation (RUP) can be exceedingly difficult. The bladder washing cytologies of 32 LGUC and 29 RUP were reviewed. The cytologic slides were examined for the presence or absence of the 28 cytologic features. The cytologic criteria showing statistical significance in LGUC were increased numbers of monotonous single (non‐umbrella) cells, three‐dimensional cellular papillary clusters without fibrovascular cores, irregular bordered clusters, atypical single cells, irregular nuclear overlap, cytoplasmic homogeneity, increased N/C ratio, pleomorphism, nuclear border irregularity, nuclear eccentricity, elongated nuclei, and hyperchromasia (p ? 0.05), and the cytologic criteria showing statistical significance in RUP were inflammatory background, mixture of small and large urothelial cells, loose monolayer aggregates, and vacuolated cytoplasm (p ? 0.05). When these variables were subjected to a stepwise logistic regression analysis, four features were selected to distinguish LGUC from RUP: increased numbers of monotonous single (non‐umbrella) cells, increased nuclear cytoplasmic ratio, hyperchromasia, and presence of small and large urothelial cells (p = 0.0001). By this logistic model of the 32 cases with proven LGUC, the stepwise logistic regression analysis correctly predicted 31 (96.9%) patients with this diagnosis, and of the 29 patients with RUP, the logistic model correctly predicted 26 (89.7%) patients as having this disease. There are several cytologic features to separate LGUC from RUP. Stepwise logistic regression analysis is a valuable tool for determining the most useful cytologic criteria to distinguish these entities.     

Fine‐needle‐aspiration cytology of a proximal type epithelioid sarcoma: A case report

Epithelioid sarcoma is a rare mesenchymal neoplasm, with an as yet unidentified cell of origin. Two subtypes of epithelioid sarcoma, distal/classic and proximal/large cell type, are recognized in the literature; with the proximal‐type having a lower incidence amongst the two. Here, we present a case of proximal‐type epithelioid sarcoma in a previously healthy young man. Fine‐needle‐aspiration of a large axillary mass was performed for diagnosis. The cytologic findings included a dispersed population of large epithelioid to polyhedral cells with abundant cytoplasm. Immunohistochemical staining showed coexpression of keratin and vimentin, as well as loss of INI1 staining, consistent with an epithelioid sarcoma, proximal subtype. Diagn. Cytopathol. 2015;43:859–862. © 2015 Wiley Periodicals, Inc.     

Cytohistology of papillary carcinoid and emerging concept of pulmonary neuroendocrine neoplasms

This timely review starts by reporting the clinical, cytologic and histologic features of a morphologic variant of pulmonary carcinoid tumor forming exclusively of papillae. This growth pattern is so rare that it was not included in 2014 WHO classification of pulmonary neuroendocrine neoplasms. The current concept is reviewed, and example of spindle cell carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma are illustrated with fine needle aspiration cytology, surgical and clinical follow‐up. Finally, the new findings in cell biology and molecular biology that led to the emerging concept that carcinoids and high‐grade neuroendocrine lung carcinomas are separate biological entities are reviewed and summarized in a tumorigenic module. Diagn. Cytopathol. 2016;44:52–60. © 2015 Wiley Periodicals, Inc.