Signet ring carcinoma parotid gland: A case report

Background Signet ring adenocarcinoma is a recently characterized entity occurring in the minor salivary glands. All reported cases have occurred in minor salivary gland. Pure signet ring adenocarcinoma of a major salivary gland has not been reported in the literature. Methods A 38‐year‐old woman presented with a mass in the parotid region. Microscopy showed signet ring cells positive for mucicarmine. Immunohistochemistry showed cytokeratin and focal smooth muscle actin (SMA) positivity; an exhaustive search for primary elsewhere did not reveal any suspicious focus. Results A diagnosis of low‐grade signet ring adenocarcinoma of the parotid gland was made. On 6‐month follow‐up the patient was alive and well. Conclusions The present case highlights a rare occurrence of this tumor in the parotid gland, which until now was labeled as a tumor exclusive to minor salivary glands. Thus this entity should be kept as a differential while investigating mucinous tumors of parotid. © 2010 Wiley Periodicals, Inc. Head Neck, 2011