Differential Diagnosis
- Single most likely diagnosis
- Femoral head chondroblastoma: This is a rare, benign tumor that typically occurs in the epiphyses of long bones, including the femoral head. The complex lesion with moderate internal heterogeneity on T2-weighted images and the absence of perilesional edema are consistent with this diagnosis. Chondroblastoma can cause pain due to the tumor's expansion and potential irritation of surrounding tissues.
- Other Likely diagnoses
- Femoral head osteonecrosis: Although the report mentions no evidence of avascular necrosis, osteonecrosis can sometimes present with atypical imaging features. The lesion's location and appearance could be consistent with an early or atypical form of osteonecrosis, which can cause pain due to the death of bone tissue and subsequent collapse.
- Intraosseous ganglion cyst: This is a benign lesion that can occur within the bone and cause pain due to the cyst's expansion and potential irritation of surrounding tissues. The complex lesion with moderate internal heterogeneity on T2-weighted images could be consistent with an intraosseous ganglion cyst.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Malignant bone tumor (e.g., osteosarcoma, chondrosarcoma): Although the imaging features are not typical for a malignant tumor, it is essential to consider this possibility due to the potential severity of the diagnosis. Malignant bone tumors can cause pain due to the tumor's rapid growth and invasion of surrounding tissues.
- Infection (e.g., osteomyelitis, septic arthritis): Infection can present with atypical imaging features, and it is crucial to consider this possibility due to the potential severity of the diagnosis. Infection can cause pain due to the inflammatory response and tissue damage.
- Rare diagnoses
- Femoral head fibrous dysplasia: This is a rare, benign condition that can cause pain due to the replacement of normal bone tissue with fibrous tissue. The complex lesion with moderate internal heterogeneity on T2-weighted images could be consistent with fibrous dysplasia.
- Femoral head aneurysmal bone cyst: This is a rare, benign lesion that can occur within the bone and cause pain due to the cyst's expansion and potential irritation of surrounding tissues. The complex lesion with moderate internal heterogeneity on T2-weighted images could be consistent with an aneurysmal bone cyst.