A Rare Variety of Adenoid Cystic Carcinoma involving Submandibular Salivary Gland

Abstract

Introduction
Adenoid cystic carcinoma, an uncommon malignant salivary gland neoplasm, is known for its long clinical course, indolent growth, neural invasion, local recurrence and late distant metastasis. Three distinct histological patterns have been identified, amongst which, solid pattern is the rarest one having the worst prognosis.

Materials And Methods
A case of sixty year old male patient presented with a swelling in the left side of the neck, below the jaw gradually enlarging during the last three years. FNAC from the neck swelling was suggestive of benign adenoma of the salivary gland, possibly basal cell adenoma or pleomorphic adenoma. Submandibular gland was excised. Histopathological examination confirmed the solid pattern of adenoid cystic carcinoma, which is the rarest among the three distinct histological subtypes of the malignancy.

Discussion
Adenoid cystic carcinoma is well known for its perineural spread. In cases of submandibular gland adenoid cystic carcinoma, surgical wide excision is very much possible and in T1 or T2 cases post-operative radiotherapy may not be needed. In our case, post operative radiotherapy was given for best local control, as the tumour showed histopathlogical solid variety, grade III pattern, which is known to have the worst prognosis.