Intrathyroidal parathyroid adenoma: Diagnostic pitfalls on fine‐needle aspiration: Two case reports and literature review

Parathyroid adenomas may occur within the thyroid, clinically simulating thyroid nodules. Fine‐needle aspiration (FNA) of these presumably “thyroid nodules” can lead to misinterpretation of cytomorphological findings because of similarities in cytological features of parathyroid and thyroid lesions. Here, we reported two cases of intrathyroidal parathyroid adenomas. One of them was misinterpreted as thyroid lesions. The other was composed exclusively of oncocytic cells and had a correct cytological diagnosis. In this study, both cases showed a new cytological feature which has not been reported in the literature: many capillaries protruding outside the three‐dimensional fragments without epithelial cells around. Diagn. Cytopathol. 2016;44:921–925. © 2016 Wiley Periodicals, 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.     

Parathyromatosis—A rare occurrence along the endoscopic tract detected on fine needle aspiration cytology

Parathyromatosis is a rare cause of recurrent or persistent hyperparathyroidism after parathyroidectomy. The knowledge of such an entity is essential for clinical suspicion as well as cytological diagnosis and can be confirmed by ancillary techniques. We report a case, previously operated endoscopically for parathyroid adenoma, who presented with recurrent hyperparathyroidism and was found to have multiple tiny subcutaneous chest wall nodules along the endoscopic tract. Fine needle aspiration cytology coupled with immunocytochemistry confirmed parathyroid tissue. Clinical awareness of this entity can help in early detection of the cause of persistent hyperparathyroidism in these patients. Diagn. Cytopathol. 2016;44:1125–1127. © 2016 Wiley Periodicals, Inc.     

EUS‐guided 22‐gauge fine‐needle aspiration versus core biopsy needle in the evaluation of solid pancreatic neoplasms

Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) is widely used for diagnosis of pancreatic lesions. The Echotip Procore Needle (Wilson‐Cook Medical) is a new 22G fine biopsy needle (FNB) for obtaining core biopsy material at time of EUS. This study aimed to compare the technical and diagnostic performance of conventional FNA and FNB. Thirty‐two patients met the design criteria for this prospective paired cohort study. All lesions sampled were solid (non‐cystic) pancreatic masses by EUS appearance. Patients were randomized to receive FNA or FNB by first attempt. A cytopathologist performed on‐site evaluations. Samples were assessed for accuracy of diagnosis, cellularity, contamination, and sufficiency for ancillary studies. Technical and diagnostic performances were compared. Compared to FNA, there was a statistically significant decreased ability of FNB to achieve a diagnosis (FNA 93.8%, FNB 28.1%, P < 0.001). FNB was diagnostically superior to FNA in 1 of 32 cases. Technical failures were observed in five cases due to resistance to advancement of the FNB needle. Regarding operator perceived ease‐of‐use, FNA outperformed FNB (P < 0.001). Eight cases had insufficient FNB material to survive tissue processing. There was no significant difference in mean specimen cellularity between devices. FNA samples showed an increased amount of contaminant (P = 0.036) but were more sufficient for ancillary studies (P = 0.502). Although deemed comparable to FNA when providing material for cytology, the pledged advantage of FNB acting like a core biopsy needle was not apparent in our series. Additional studies are needed before routine adoption of 22G FNB can be recommended. Diagn. Cytopathol. 2014;42:751–758. © 2014 Wiley Periodicals, Inc.     

Cytomorphologic features of fine‐needle aspiration of liposarcoma

The cytomorphologic features of fine‐needle aspirates (FNA) of liposarcomas have not been fully characterized. In the current study, we attempted to identify cytological attributes of liposarcoma in FNA. Twelve FNAs of histologically proven liposarcomas were used for this study. They included 10 myxoid and two well‐differentiated liposarcomas. Four cytological criteria were chosen for evaluation. These included a complex capillary network, increased cellularity, the presence of a metachromatic stroma for myxoid liposarcoma, and finally the identification of lipoblasts. Eighteen FNAs of lipomas and 17 FNAs of nonlipomatous soft‐tissue sarcomas were used as controls for evaluation of the same features. The diagnosis of liposarcoma had been rendered on FNA in 7 cases (58%). The diagnosis was suggested in 3 cases (25%), and a suggestion of sarcoma was rendered in 2 cases. Complex capillary networks were identified in 9 of 12 cases (75%); this was seen in 8 of the 10 myxoid liposarcomas and 1 of the 2 well‐differentiated neoplasms. Increased cellularity was seen in 7 of 12 cases (58%), metachromatic stroma was seen in 3 of 12 cases (25%), and lipoblasts were identified in 4 of 12 cases (33%). None of the lipomas or sarcomas exhibited a complex capillary network. When capillaries were identified in lipomas, they were straight, with minimal branching. The lipomas did not show evidence of increased cellularity in any cases. Metachromatic stroma was more frequently seen in the nonlipomatous sarcomas than in the liposarcomas. No lipoblasts were identified in any of the control FNAs. Diagn. Cytopathol. 1999;20:67–69. © 1999 Wiley‐Liss, Inc.     

Metastatic small cell osteosarcoma to the liver: A diagnostic pitfall for fine‐needle aspiration cytology

We report the fine‐needle aspiration cytology of a case of metastatic small cell osteosarcoma to the liver with rosette formation, originating from distal femur, in a 36‐year‐old female. The aspirate of the liver metastases revealed a relatively monomorphic population of mitotically active small blue round cells arranged in clusters with prominent rosette formation simulating a neuroendocrine carcinoma or other rosette‐forming small round cell tumors such as Ewing sarcoma. No extracellular mineralized matrix material was present. Comparison of the liver aspirate with the biopsy from the distal femoral lesion was crucial in reaching the correct diagnosis of metastatic small cell osteosarcoma with rosette formation. This is a potential diagnostic pitfall, particularly if interpreted without the knowledge of a suspected primary bone tumor. Diagn. Cytopathol. 2014;42:161–164. © 2012 Wiley Periodicals, Inc.     

Hodgkin's lymphoma: Diagnostic difficulties in fine‐needle aspiration cytology

It is commonly believed that cytodiagnosis of Hodgkin's lymphoma (HL) is much easier than that of non‐Hodgkin lymphoma (NHL). However, recognition of certain NHL subtypes with Reed‐Sternberg (R‐S)‐like cells and results of immunohistochemical studies point to the contrary. To study the limitations of cytology in diagnosis of HL, fine‐needle aspiration (FNA) smears of 130 lymphoma or suspected lymphoma cases were reviewed. Initial and reviewed cytodiagnoses were compared with histopathology in 89 cases. Immunocytochemical and immunohistochemical studies were performed in 56 and 59 cases, respectively. Among histologically diagnosed HL cases, definitive cytodiagnosis of HL (initial as well as reviewed) was significantly less frequent than cytodiagnosis of NHL among histologically diagnosed NHL cases (P = 0.0328 and = 0.0001, respectively). On the other hand, cytologically diagnosed HL/NHL cases were significantly more frequent in the former group (P = 0.0001 and = 0.0018, respectively). ALCL and TCRBCL were the two NHL subtypes which created confusion with HL in FNA smears. Twenty‐one cytohistological concordant HL cases and equal number of discordant cases were compared. When compared with discordant group, the patients in concordant group were significantly younger (P = 0.045). Hodgkin/Hodgkin‐like cells and typical R‐S cells were significantly more frequent in FNA smears of the concordant group (P = 0.0478 and = 0.0431, respectively). Immunocytochemical and immunohistochemical studies showed good correlation with histological diagnosis of HL. It is suggested that proper interpretation of cytologic features, together with use of immunocytochemical parameters can help in reducing the margin of error in cytodiagnois of HL. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.