Metatypical Basal Cell (Basosquamous) Carcinoma of the Temporal Bone Presenting as a Post-aural Ulcer, with Paresis of the Vagus and Spinal Accessory Nerves: A Case Report
摘要
Basal cell carcinoma (BCC; “rodent ulcer”) is the commonest amelanotic cutaneous malignancy that is prevalent in the tropical regions like India and is encountered in the sun-exposed areas of the body. It is notorious for being locally erosive rather than for distant or locoregional metastasis. However, one of its rare variants, the metatypical BCC (MTBCC), that shares histologic and behavioral properties with squamous cell carcinoma, is characterized by its aggressive nature and tendency for recurrence. This clinical record describes a 61-year-old farmer, who was operated for BCC of the scalp 4 years ago, presenting with an ulcerative BCC of metatypical variety in his left post-auricular region, along with another nodular lesion in the ipsilateral cervical region. The post-auricular MTBCC was aggressive enough to erode through the mastoid, and involve the skull-base with paresis of the ipsilateral Xth and XIth cranial nerves, but not involving the jugular foramen. The neck mass was inconclusive on fine needle aspiration cytology which reported it to be malignant epithelial neoplasm. With the extensive local infiltration of the lesion into the skull-base with cranial nerve pareses, and suspected locoregional spread (metastatic cervical lymphadenopathy, and perineural invasion), the patient was offered concurrent chemoradiation. This present clinical illustration describes a rare histologic variant of BCC and documents the severity of its local aggressiveness as represented by recurrence, multiple cranial nerve pareses, and suspected locoregional spread.