Primary Parotid Tuberculosis Presenting as a Malignancy: An Exceptional Occurrence

Abstract

Tuberculosis is a well-known endemic disease in India; however extra-pulmonary tuberculosis in the form of single parotid gland involvement is exceptionally unusual. Nevertheless, in instances involving slow-growing, prominent parotid gland enlargement, where malignancy is our major speculation, it should never be eliminated as a differential. There have been very few previously reported cases of tuberculosis involving salivary glands, and at times imaging has proven it difficult to diagnose such a condition and differentiate it from a benign mass or a malignancy. With that in mind, the authors present a case of tuberculosis involving just a single parotid gland in a 49-year-old woman who had been experiencing unilateral infra-auricular swelling and pain for a month. Apart from evening rise in temperature and generalised weakness, the patient had no additional symptoms suggestive of tuberculosis infection. Ultrasound represents the initial imaging modality of choice for assessment of the parotid gland. A sonographic examination of the authors’ patient revealed a diffusely enlarged left parotid gland with peripherally vascular hypo-echoic areas within. On contrast-enhanced CT the left parotid gland was seen to be replaced by a heterogeneously enhancing lesion, with an abscess-like appearance. The tubercular aetiology was established after a USG-guided tru-cut biopsy from the infra-auricular region revealed numerous loose granulomas with few langhans-type multinucleate giant cells amidst foci of necrosis and a salivary duct. Anti-TB medication was initiated for the patient subsequent to the presence of acid-fast bacilli on Ziehl-Neelsen staining. The patient has now received 3 months of AKT and there has been complete resolution of the symptoms.