<prompt> Cocks peculiar tumor isBasal cell CASquamous cell CAUlcerated sebaceous cystCylindroma  <response>: Ans is c i.e. Ulcerated sebaceous cyst Repeat from May 04Cocks peculiar tumor is actually a complication of sebaceous cyst.- When the sebaceous cyst of the scalp ulcerates excessive granulation tissue forms resembling fungating epithelioma. This is called cocks peculiar tumor.Also know these termsCylindroma-A malignant epithelial tumour also ka Turban tumorKnown as cylindroma because of histological appearancePilomatrixoma Calcifying epithelioma of Malherbe -It is a benign hair follicle derived tumour.Potts puffy tumour -It is osteomyelitis of the skull associated with subperiosteal swelling and edema. 