Invasive salivary duct carcinoma ex pleomorphic adenoma of the parotid gland: a teaching case giving rise to the genuine diagnostic difficulty on an inadequate cytology specimen

Abstract

A history of a recent rapid increase in long-standing swelling mass was presented in the right parotid gland of an 85-year-old male. The inadequate cytologic specimens contained few small clusters of three-dimensional malignant epithelial cells having hyperchromatic pleomorphic nuclei and prominent nucleoli, adjacent to a cluster of benign monomorphic myoepithelial cells. We first interpreted it merely as an adenocarcinoma, not otherwise specified. A radical parotidectomy was performed, and gross examination revealed an encapsulated and firm tumor lesion, looking grayish-blue to yellowish-white, focally associated with extracapsular invasion. On microscopic examination, the tumor was predominantly composed of a proliferation of highly atypical epithelial cells having abundant eosinophilic cytoplasm, often arranged in a Roman-bridge appearance with foci of comedo necrosis, alternating with extensive infiltration to adjacent stroma in a trabecular or alveolar fashion with severe vessel permeation. Within the background of pleomorphic adenoma, the carcinoma cells sometimes replaced ductal luminal cells while retaining an intact-like myoepithelial layer. Therefore, we finally made a diagnosis of invasive salivary duct carcinoma ex pleomorphic adenoma. We should be aware that owing to its characteristic features, cytopathologists might be able to determine correct diagnosis, based on multiple and adequate samplings.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2126158270695815

Salivary duct carcinoma: a case report with cytological and pathological features

“…Cancer cells in this case exhibited pathological and immunohistochemical findings similar to those reported previously [1,[6][7][8][9][10][11][12]. Although salivary duct carcinoma is one of the most aggressive salivary gland malignancies, the patient reported here is free of metastasis and recurrence 36 months after the surgery.…”

Pleomorphic carcinoma of the breast associated with cyst formation: a unique surgical case focusing on cytological and immunohistochemical findings. Cystic breast PC

“…Although there have been no large, detailed immunohistochemical studies of PC of the breast, to date, our data imply that those carcinoma cells might have potential squamous, myoepithelial, and/or basal-like phenotypes, and epithelial-mesenchymal transition (EMT), as well, supported by some published papers [14,16]. We might provide the possible evidence that PCs arise from ductal epithelial-myoepithelial cells, as a result of neoplastic transformation of outer supporting myoepithelial cells, as well as inner ductal epithelial cells [17,18]. However, since other myoepithelial markers examined, such as α-SMA, S-100 protein, p63, and calponin, were completely negative, this implication would be highly speculative and unlikely.…”

Basaloid carcinoma of the lung associated with central cavitation: a unique surgical case focusing on cytological and immunohistochemical findings

“…Although there have been no large, detailed immunohistochemical studies of BC of the lung until now, the results indicate that those tumor cells have potential myoepithelial phenotypes, as well. We could provide the possible evidence for the first time that BC of the lung might arise from a ductal epithelial-myoepithelial cell, as a result of neoplastic transformation of outer supporting myoepithelial cells, as well as inner ductal epithelial cells [13]. However, since other myoepithelial markers examined, such as α-SMA, calponin, and CD10, were negative (Table 2), this suggestion may be highly speculative and partly unsupported.…”