Sebaceous carcinoma - An overlooked tumour in Black Africans

Abstract

Background: Sebaceous carcinoma is an uncommon malignant adnexal tumour with female preponderance and peak age presentation in the seventh decade of life. It is overlooked in the plethora of cutaneous tumours in general because of its rarity and diagnosis is often missed or delayed, thus increasing disease morbidity. Materials and Method: Formalin fixed, paraffin processed tissue biopsies stained with haematoxylin & eosin, oil red O and immunohistochemical antibodies for EMA, S100, CD15 and Ki67 were studied over a 14year period in a Pathology laboratory. Results: Six males and one female were diagnosed during the period. They had mean age of 44.7years and a range of 25years to 65years. Patients’ symptoms included orbital mass and ulceration, conjunctiva mass, visual loss, ulcerated axillary mass and contact bleeding. Two patients gave history of recurrent conjunctiva growths. Clinical diagnoses included melanoma, lymphoma, basal and squamous cell carcinomas. Histology sections from all seven patients showed
varying sized irregular lobular formations of undifferentiated and distinct sebaceous cells exhibiting considerable nuclear and nucleolar pleomorphism with pagetoid spread of malignant cells in the eyelid and conjunctiva epithelium. Immunoreactivity for epithelial membrane antigen (EMA) was demonstrated in all the cases. Conclusion: Middle aged males were predominantly affected. The extraocular type involved the axilla mainly as fungating masses and over seventy percent of the cases were ocular with associated extensive destruction of ocular structures and visual loss. None of the clinical diagnosis considered sebaceous carcinoma.