This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plastic & Reconstructive Surgery, Subject name: Surgery
What is Cock's Peculiar tumour - 
Select and explain. 
A. Ulceration of sebaceous cyst on the scalp, B. Calcifying epithelioma, C. Mesothelioma of pleura, D. Osteomylitis of skull
A: Ulceration of sebaceous cyst on the scalp
Answer: A: Ulceration of sebaceous cyst on the scalp 
Explanation: 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 cock's peculiar tumour.Also know these terms -o Cylindroma -# A malignant epithelial tumour also k/a Turban tumor# Known as cylindroma because of histological appearanceo Pilomatrixoma (Calcifying epithelioma of Malherbe)# It is a benign hair follicle derived tumouro Pott's puffy tumour# It is osteomyelitis of the skull associated with subperiosteal swelling and edema.