Histomorphological and Immunohistochemical Reappraisal of Cutaneous Adnexal Tumours: A Hospital Based Study

Abstract

Background. Diagnosing adnexal tumours of the skin is a challenge due to their wide variety, infrequent occurrence in practice, and confusing morphological picture. Aims and Objectives. The present study aims to observe the spectrum of adnexal tumours at our institute and to evaluate them based on histomorphological, histochemical, and immunohistochemical methods either alone or in combination for proper identification and classification. Materials and Methods. A partly retrospective and partly prospective study was conducted on adnexal skin tumours over a period of 6 years. Relevant clinical profile was recorded. Histopathological examination was carried out and special stains were applied as and when required. Immunohistochemistry was performed where diagnosis with routine stains was not possible. Results. A total of 150 skin tumour biopsies were received. There were 87 keratotic tumours, 39 adnexal tumours, and 24 melanocytic tumours. Amongst the adnexal tumours, 51.3% eccrine, 30.8% follicular, and 17.9% sebaceous tumours were seen. In five cases, histological diagnosis was troublesome where immunohistochemistry helped in making final diagnosis. Limitations. The sample size is small. Conclusion. Histomorphology is confirmatory in majority of the adnexal tumours but few rare lesions that mimic internal malignancy require a panel of immunomarkers to rule out other possible differentials.

Clinicopathological Study of Skin Adnexal Tumors with Special Emphasis on the Line of Differentiation

“…[7] In our study, the incidence of benign lesions (94.3%) is more compared to malignant counterpart (5.7%). It was tandem with other studies conducted by Vani et al, [12] Shukla P et al, [5] Samaila et al, [9] and Vaibhavi Bani et al [1] These tumors basically originate from undifferentiated pluripotent stem cells, determining its preponderance to behave in a benign fashion. These tumors are influenced by genetics, local vascularity, and microenvironment of epidermis & dermis in its malignant transformation.…”

“…[4] This signifies that though most of the adnexal neoplasms are benign in nature, they are genetically predetermined which in course of time become pre-malignant and aggressive in nature. [5] Clinically adnexal neoplasm presents as asymptomatic papules or nodules, having non-specific morphological appearance and therefore histopathology is the gold standard for their confirmatory diagnosis. [6] The added advantage of histopathological examination is that it will also yield the prevalence of pre malignancies, which would otherwise be missed in the routine clinical workup and even with usage of sophisticated technologies such as computerized tomography.…”

Differences in the diagnosis of sweat gland tumors with other histopathologically similar skin tumors

“…2 Verrucous hyperplasia and lobular formation with clear cells are diagnostic features of trichilemmoma. 14 Peripheral palisade and absence of ducts distinguish trichilemmoma from hidradenoma. 7 Immunohistochemical examination of trichilemmomas using CD34, CD10, and CK5/6, tumor cells showed negative CD34, but stromal cells showed positive diffuse CD34.…”