A malignant proliferating trichilemmal cyst arising on the elbow of a man: A case report and review of the literature

This case report details a rare instance of a malignant proliferating trichilemmal cyst (MPTC) on the elbow of a 77-year-old man, a location uncommon for such tumors. MPTCs are aggressive skin cancers that originate from proliferating trichilemmal cysts (PTCs), which are themselves rare and typically benign. The patient underwent a wide excision and bursectomy, followed by fascia reconstruction due to deep tumor invasion. Post-surgery, a suspected recurrence was identified as bursitis, not cancer. After 1 year, the patient showed no signs of recurrence. This case highlights the importance of recognizing MPTC in atypical locations and the effectiveness of surgical intervention.