This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pulmonary Tuberculosis and Lung Abscess, Subject name: Pathology
A young lady presented with bilateral nodular lesions on shins. She was also found to have bi-lateral hilar lymphadenopathy on chest X-ray. Mantoux test reveals indurations of 5 mms. Skin biopsy would reveal: 
Select and explain. 
A. Non caseating granuloma, B. Vasculitis, C. Caseating granuloma, D. Malignant cells
A: Non caseating granuloma
Answer: A: Non caseating granuloma 
Explanation: The presence of bilateral nodules on the shin (ERYTHEMA NODOSUM); bilateral hilar lymphadenopathy and negative Mantoux test in a female patient point to a probable diagnosis of Sarcoidosis. The skin lesions characteristically show the presence of non - caseating granulomasQ in sarcoidosis.