Acinic Cell Carcinoma with Extensive Neuroendocrine Differentiation: A Diagnostic Challenge

Abstract

Primary salivary gland carcinoma with neuroendocrine differentiation is of rare occurrence, especially so in the parotid gland. Amongst the various reported primary tumors with neuroendocrine differentiation, acinic cell carcinoma (ACC) one such tumor. A 48 year old lady presented with a gradually increasing right infra-auricular swelling for a period of 1 year which enlarged suddenly in a short period. Contrast Enhanced Computed Tomography (CECT) suggested diagnosis of Pleomorphic Adenoma. Fine Needle Aspiration Cytology (FANC) yielded a cystic fluid suggesting a possibility of Warthin’s tumor or Oncocytic lesion. Intraoperative findings were suggestive of a Warthin’s tumor. Initial histopathological examination of the tumor was suggestive of neuroendocrine carcinoma. However, extensive sectioning revealed peripheral islands of ACC. Immunoexpression of S-100, Neuron specific Enolase (NSE), Chromogranin A and Synaptophysin confirmed the diagnosis. The possibility of neuroendocrine differentiation in a primary salivary gland tumor should be kept in mind whenever a salivary gland tumor shows only neuroendocrine histology.

Squamoglandular Variant of Acinic Cell Carcinoma: A Case Report of a Novel Variant

“…While acinic cell carcinomas with neuroendocrine elements have been described, the neuroendocrine component is typically minor in such cases. [24] NUT carcinomas are often phenotypically squamous and have somewhat of a basaloid appearance. However, while some NUT carcinomas may be somewhat monomorphic, they still tend to have more mitotic activity and are generally more infiltrative than our case.…”

Acinic Cell Carcinoma

“…Calcifi cations are particularly common in this variant of ACC. On rare occasions, ACC may show extensive neuroendocrine differentiation [ 69 ]. The many faces of ACC are becoming increasingly apparent after recognition of mammary analogue secretory carcinoma (MASC, see Chap.…”