Giant Proliferating Trichilemmal Tumour: A Case Report

A Trichilemmal Cyst (TC), which can also be referred to as a trichodermal cyst or trichodermal isthmus-degenerative cyst, is a noncancerous growth on the skin that arises from the outer sheath of hair follicles and is characterised by its rare occurrence and limited documentation. Herein, we report a 54-year-old female who presented with a swelling over her scalp for 15 years, which gradually progressed to a size of 8×5 cm. Computed Tomography (CT) scan revealed an extra-cranial well-defined lobulated heterogeneously enhancing isointense lesion with specks of calcification above the occipital bone in the midline with no intracranial or bony extension, likely benign in aetiology. She underwent surgical excision of the entire swelling, and histopathological analysis confirmed the diagnosis of Proliferating Trichilemmal Tumour (PTT) with squamous differentiation. The wound healed well without any recurrence after a follow-up of one year. Inspite of their enhanced propagation, TCs are usually benign and non-invasive. But in a few cases, these can transform to trichilemmal carcinoma, these carcinomas may cause local invasion, resulting in significant morbidity and mortality