Unusual case of skull base adenoid cystic carcinoma presenting as skull base osteomyelitis: case report

Abstract

Abstract Background Adenoid cystic carcinoma is a rare malignancy. Tumours of palatal region with minor salivary gland origin do not generally present at an early stage as the tumour is submucosal with symptoms prevalent only when there is evidence of perineural spread of the tumour. We report a case of adenoid cystic carcinoma of the palate with rare presentation of left ear discharge and diplopia on left lateral gaze. We discuss the case with emphasis on imaging evaluation mimicking a case of infective etiology with adjacent skull base osteomyelitis on initial presentation. However, on follow-up and further evaluation the patient was diagnosed as adenoid cystic carcinoma of hard palate on left side. Case presentation A 25-year-old male patient has presented to Jagadguru Sri Shivarathreeswara Hospital in August 2019 with complaints of left ear discharge and diplopia on left lateral gaze since 1 week. The clinical and imaging findings was suggestive of infective etiology and the patient was treated for the same with IV antibiotics. Repeat magnetic resonance imaging was then done which revealed definitive reduction in the severity of inflammation suggestive of response to therapy. Patient was then discharged and was followed up. Three months later, the patient came with complaints of mass in left nasal cavity. Patient was then referred for contrast enhanced computed tomography neck strongly suggestive of neoplastic etiology. The patient was then operated and histopathological examination of the biopsy revealed adenoid cystic carcinoma. Conclusions Tumours of palatal region with minor salivary gland origin do not generally present at an early stage as the tumour is submucosal with symptoms prevalent only when there is evidence of perineural spread of the tumour. In our case patient presented with lateral rectus palsy, involvement of meckel’s cave, trigeminal nerve involvement and cavernous sinus involvement which are strong indicators of the perineural and locoregional spread of the tumour. Hence, it is important for the radiologist and clinician to strongly suspect and evaluate for a primary lesion of the head and neck when such a radiological presentation has been demonstrated.

Keywords

• Carcinoma
• Adenoid cystic
• Cylindroma
• Skull base
• Osteomyelitis
• Neoplasm invasiveness