Myoepithelial carcinoma with predominance of plasmacytoid cells arising in a pleomorphic adenoma of the parotid gland

Plasmacytoid urothelial carcinoma of the bladder

“…The observed positivity for CD138, also an immunohistochemical marker for plasma cells, in 3 (27%) of our cases is in line with other recent reports [4,8,10] and highlights an important potential diagnostic pitfall because of the morphological resemblance of tumor cells to plasma cells, mainly in tumors with pure plasmacytoid morphology or in case of chronic cystitis with predominant plasma cell infiltrate. Several tumors have the potential to demonstrate plasmacytoid morphology (Table 3), although in general, this is a rare finding [4]; myoepithelial tumors and medullary carcinoma of the thyroid, melanoma, paraganglioma, neuroendocrine carcinoma, lymphoma, myeloma, and some sarcomas are in the spectrum [4,[17][18][19][20][21][22][23][24][25][26][27].…”

“…In the urinary bladder, the main differential diagnostic considerations of plasmacytoid urothelial carcinoma include benign conditions such as chronic cystitis with prominent plasma cell infiltrate, as well as other malignant tumors such as plasmacytoma, signet ring cell adenocarcinoma, and metastatic carcinoma from other primary sites, specifically breast and stomach [1][2][3][4][17][18][19][20][21][22][23][24][25][26][27]. Rarely, myofibroblastic proliferations enter the differential diagnosis because they may have a prominent plasma cell infiltrate.…”

“…At about the same period, Zuckerberg et al [14] reported their series of bladder tumors simulating malignant lymphoma, one of them showing malignant cells with eccentric nuclei resembling plasma cells. After these initial reports, several publications discussed the differential diagnosis of a hematolymphoid malignancy in this setting, particularly a plasmacytoma/ myeloma in the initial, frequently limited, biopsy sample [4,[17][18][19][20][21][22][23][24][25][26][27]. Primary plasmacytoma of the bladder is rare, but in patients with a prior history of multiple myeloma, where there is no identifiable surface urothelial component, it is necessary to maintain a level of suspicion to avoid misdiagnosis of a plasmacytoma as urothelial carcinoma with plasmacytoid features [4,[17][18][19][20][21][22][23][24][25][26][27].…”

Plasmacytoid cells in salivary-gland pleomorphic adenomas: evidence of luminal cell differentiation

“…In conclusion, we would like to propose that plasmacytoid cell tumors should not be considered a subtype of myoepithelioma but classified as plasmacytoid adenomas or adenocarcinomas [21]. In this context, it is noteworthy that malignant myoepitheliomas with predominant plasmacytoid cells exhibit more aggressive behavior than the other forms of these tumors [17,49]. After the analysis of a large series of myoepithelial carcinomas, Savera et al [41] concluded that the cell type and the prognosis did not show a statistically significant correlation.…”

Fine Needle Aspiration Biopsy of the Parotid Gland

“…The epithelioid subtype has been by far the most common, 16 whereas the plasmacytoid subtype has been found to be associated with a worse prognosis. 20,28 …”