Question

an 11-year-old male presents with painful mass on his left arm. it has enlarged over the past several months. what is the most likely diagnosis?
a) chondrosarcoma
b) osteosarcoma
c) metastasis
d) osteoblastoma
e) lymphoma
f) ewing sarcoma

Explanation:

Osteosarcoma is the most common primary bone malignancy in children and adolescents, typically presenting as a painful, enlarging mass in long bones (like the arm). Chondrosarcoma affects older adults; metastasis requires a primary tumor (unmentioned here); osteoblastoma is rare and less likely to present this way in this age group; lymphoma usually presents with systemic signs or lymph node involvement; Ewing sarcoma is less common than osteosarcoma in this context and often has more systemic symptoms.

Answer:

B) osteosarcoma