Trichilemmal carcinoma of the axilla with regional lymph nodes metastasis: A case report

INTRODUCTION AND IMPORTANCE: Trichilemmal carcinoma is a rare malignant cutaneous adnexal neoplasm of hair follicles originating from the external root sheath epithelium. The diagnosis is rarely made clinically and is still challenging for an experienced pathologist. AIM: To report a rare case of trichilemmal carcinoma presenting as a right axillary mass with regional lymph nodes metastasis and was treated with wide local excision in the General Surgery Department Jordanian Royal Medical Services (JRMS), Jordan. CASE PRESENTATION: A 45-year-old presented with a right axillary mass of six-month duration. Physical examination revealed a hyperemic, thickened skin of both armpits with a palpable 5-cm mass in the right axilla. He underwent an excisional biopsy of the right mass. Histopathologic examination revealed a malignant adnexal skin tumour with foci of trichilemmal-type keratinisation. It was excised with adequate margins. CLINICAL DISCUSSION: Trichilemmal carcinoma usually occurs on the forehead, scalp, neck, back of hands and trunk. These neoplasms are rare lesions presenting as locally aggressive, low-grade carcinomas and have the potential for nodal involvement and distant metastasis. Therefore, the establishment of a correct diagnosis is vital to guide the treatment plan. Wide excision with adequate tumour-free margins is considered a curative treatment and offers a successful outcome. CONCLUSION: Malignant cutaneous adnexal tumours are one of the most challenging subjects of dermatopathology. Surgical excision is always required to establish a definitive diagnosis and differentiation subtypes. Trichilemmal carcinoma is a relatively rare tumour, mainly when located in the axilla.