Clinical and Histomorphological Features of Cutaneous Adnexal Neoplasms: A Series of Eighteen Cases

Abstract

Cutaneous Adnexal Neoplasms (CAN) are rare skin tumours with varied morphology that are often misdiagnosed clinically. The definitive diagnosis of these tumours can only be made by Histopathology (HP) based on their appendage differentiation. Though rare in occurrence, diagnosing these tumours is of prime importance, as they can mimic primary cutaneous carcinomas, cutaneous metastasis of a primary tumour, or can serve as markers of internal malignancy. Excision is mostly curative in benign tumours, and wide local excision needs to be performed to prevent recurrences. The aim of the present case series study was to investigate the histopathological spectrum of different CANs based on their appendage differentiation in a hospital-based study. A retrospective analysis was conducted over a period of 4.5 years, and all CAN cases diagnosed on HP were classified according to their appendage differentiation. The concordance between histopathological diagnosis and clinical diagnosis was calculated. Additionally, the frequency distribution of CAN in relation to demographic data was analysed. In the present case series, 18 cutaneous adnexal tumours were reported, showing a female predominance. The majority of the tumours 12 (66.67%) cases were observed in the head and neck region and exhibited a predominance of sweat gland differentiation 12 (66.67%) cases. The most common CANs were eccrine spiradenoma and pilomatrixoma, with 3 (16.67%) cases each. Sebaceous carcinoma and a rare case of Malignant Proliferating Trichilemmal Tumour (MPTT) accounted for 2 (11.11%) cases, being the only malignant tumours reported. The present study demonstrated only concordance of 4 (22.22%) cases between clinical and HP diagnosis. Therefore, the present series emphasises the importance of appendage differentiation in HP, which plays a crucial role in the definitive diagnosis, treatment planning and prognosis in CAN.

Keywords

• appendage
• hair follicle
• malignant proliferating trichilemmal tumour
• sebaceous carcinoma