<prompt> What is Cocks Peculiar tumour -Ulceration of sebaceous cyst on the scalpCalcifying epitheliomaMesothelioma of pleuraOsteomylitis of skull  <response>: Ans. is a i.e., Ulceration of sebaceous cyst on the scalp o Cocks peculiar tumour 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 tumour.Also know these terms -o Cylindroma - A malignant epithelial tumour also ka Turban tumor Known as cylindroma because of histological appearanceo Pilomatrixoma Calcifying epithelioma of Malherbe It is a benign hair follicle derived tumouro Potts puffy tumour It is osteomyelitis of the skull associated with subperiosteal swelling and edema. 