An invasive adenocarcinoma of the accessory parotid gland: a rare example developing from a low-grade cribriform cystadenocarcinoma?

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1226764594634693 webcite.Delgado et al originally described low-grade cribriform cystadenocarcinoma (LGCCA) as a rare low-grade variant of salivary duct carcinoma (SDC) in 1996 [1]. This tumor predominantly consists of intraductal components of the tumor and frequently exhibits papillary-cystic or cribriform proliferation similar to a low-grade ductal carcinoma in situ or atypical ductal hyperplasia of the breast in its histology and biologically indolent features [1-9]. This low-grade variant of SDC makes a contrast with conventional SDC, which is a clinically aggressive tumor that exhibits high-grade histology similar to an invasive ductal carcinoma of the breast [10,11]. Evidence for distinct relationships between these 2 entities has not been demonstrated; therefore, this low-grade variant of SDC is categorized as a variant of cystadenocarcinoma, termed LGCCA, in the World Health Organization classification (2005) due to its cystic morphology [2]. Past literatures have described rare cases with LGCCA that subsequently exhibited overt invasive growth in their clinical courses [6]. Herein, we present a case of invasive adenocarcinoma of the accessory parotid gland in a young male that had left vestiges of LGCCA in its histology. The invasive component of the tumor was histologically defined as adenocarcinoma, not otherwise specified (ANOS). This is an interesting case suggests that ANOS could secondarily arise from LGCCA of the salivary gland.A 27-year-old man with more than 1-year history of a subcutaneous tumor in his left cheek consulted the Department of Plastic Reconstructive Surgery at our hospital. His past medical history and family history were unremarkable. Physical examination revealed an elastic hard tumor in the subcutis of his left cheek. The tumor did not adhere to the skin. There was no remarkable abnormality in his oral and nasal cavities. No lym