Mast cell tumors originate from which cell type?

• A. Lymphocytes
• B. Mast cells
• C. Neurons
• D. Erythrocytes

Answer: (B)

Mast cell tumors arise from mast cells, which are tissue-resident immune cells derived from bone marrow precursors and located in connective tissue. These cells store granules with mediators like histamine and heparin, and when they undergo malignant transformation, they form mast cell tumors. Lymphocytes, neurons, and erythrocytes are not the origin of this tumor type—lymphocytes are adaptive immune cells, neurons are nerve cells, and erythrocytes are red blood cells.