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.
Singh
Meeta
M
Department of Pathology, Maulana Azad Medical College and Lok Nayak Hospital, Bahadur Shah Zafar Marg, New Delhi, India. meetamamc@gmail.com
Khurana
Nita
N
Wadhwa
Rachna
R
Gulati
Achal
A
D000328:Adult; D001707:Biopsy, Needle; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology* / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D010307:Parotid Neoplasms / Q000473:pathology* / Q000601:surgery*; D035583:Rare Diseases; D018570:Risk Assessment; D016896:Treatment Outcome