Exploring the Histomorphology of Cutaneous Adnexal Tumors: Insights into Predominant Line of Differentiation and Malignant Tumor Trends

Abstract

Introduction: Cutaneous adnexal tumors represent a diverse group of neoplasms that differentiate into one or more adnexal structures typically found in normal skin. While the overall incidence of these tumors is low, their diagnosis can be challenging.

Objectives: Our study aims to analyze the histomorphological features of various CATs, focusing on factors such as age, sex, predominant line of differentiation, the frequency of malignant tumors in each variant, and comparison of our findings with those of previous studies.

Methods: This study was conducted from January 2022 to December 2024, involved specimens of wide local excision and edge biopsies received in 10% neutral formalin at the Department of Pathology, MMCRI, Mysore. Specimens were fixed for 24 hours, processed, sectioned, and the slides were subjected to automated haematoxylin and eosin staining. These slides were examined.

Results: 52 cases were diagnosed as CATs, representing 36.5 % of tumors with eccrine gland differentiation, which is the predominant line of differentiation, followed by those showing hair follicle differentiation (32.6%), sebaceous differentiation (21.1%), and apocrine gland differentiation (7.6%). The age range of patients was from 08 to 85 years, with a male-to-female ratio of 1.2:1. Benign tumors (78.8%) were predominant, while 21.1% were malignant. Malignant tumors were frequent in sebaceous differentiation.

Conclusions: Skin adnexal tumors are relatively rare neoplasms. Histopathology is quite essential from a diagnostic point of view. Malignant cases are less common than benign ones. Eccrine tumors are the predominant line of differentiation. Malignant tumors are frequent with Sebaceous differentiation.