Histomorphological Spectrum of Adnexal Tumours of the Skin: A Descriptive Study from a Tertiary Care Centre in Karnataka, India

Abstract

Introduction: Skin Adnexal Tumours (SAT) are a category of rare and most uncommon tumours. They could display multiple lines of differentiation such as follicular, eccrine, apocrine, sebaceous, and sometimes mixed differentiation, generating a mistaken diagnosis that might lead to unwarranted and unnecessary interventions. Aim: To describe the types and microscopic features of adnexal tumours. Materials and Methods: The present study was a retrospective study on SAT received for histopathology at the Department of Pathology, Mandya Institute of Medical Sciences, Mandya, Karnataka, India, from January 2018 to June 2022 during the study period of September 2022 to March 2023. The records of patients including age, gender and site were retrieved from the registers maintained at the department and Haematoxylin and Eosin (H&E) stained slides were examined and the data was analysed by descriptive statistics. Results: A total of 62 cases were included in the study out of which, 59 (95.2%) cases were found to be benign and 3 (4.8%) cases were malignant. The mean age was found to be 43.87 years. A total of 28 (45.1%) cases were seen in the age group of 21 to 40 years. Females outnumbered the males with 32 cases (51.6%). A maximum number of cases belonged to the group of sweat gland tumours (29/62, 46.8%) followed by hair follicle tumours (21/62, 33.9%) and sebaceous gland tumours (12/62, 19.3%). Nodular hidradenoma was the commonest sweat gland tumour (12/29, 41.4%), pilomatricoma was the commonest hair follicle tumour (10/21, 47.6%) and sebaceous adenoma was the commonest sebaceous gland tumour (10/12, 83.3%). The most common malignancy was sebaceous carcinoma (2/3, 66.67%). The male-to-female ratio was found to be 1:1.06. Conclusion: The incidence of SAT was low with the majority being benign tumours. Malignant tumours are even rarer and are often mistaken for cutaneous epithelial malignancies. These lesions may prompt the clinician towards unwanted surgery or treatment for the patient. They exhibit a wide variety of morphological patterns which may be confused for primary from other sites. In such cases, histopathological examination becomes necessary. Hence, a combination of good clinical expertise and histopathological confirmation by the pathologist helps appropriately manage the patient.