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AAOS Now

Published 1/1/2011

What’s your Diagnosis?

In November, Valerae O. Lewis, MD, of the MD Anderson Cancer Center in Houston, Texas, provided the following information and images:

“The patient is a 14-year-old male who was seen for pain and swelling in the left knee. Plain film radiograph (A) revealed eccentric radiolucency with an osteolytic lesion of the distal lateral femur. A bone scan did not reveal any indication of femoral lesion. An MRI of the left femur showed a focal mass in the lateral aspect of the femoral epiphysis, with surrounding edema (B). A biopsy (C) was taken.”

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A, Plain radiograph showing osteolytic lesion of the distal lateral femur; B, MRI of the left femur—a focal mass can be seen in the lateral aspect of the femoral epiphysis, with surrounding edema; C, Hematoxylin-eosin staining of the biopsy specimen (×100).

Did you get it right?
According to Dr. Lewis, the first biopsy revealed low grade malignancy consistent with chondroblastoma. She was unable to confirm the diagnosis, however, with a frozen section. Even though the lesion was thoroughly curetted back to the rim of the reactive bone and bone grafting performed, the tumor recurred. An open biopsy after tumor recurrence indicated high grade malignant adenocarcinoma with a suggestive gastrointestinal primary carcinoma. The patient received a full work-up, but the primary tumor was not found. Two years later, afer receiving radiation to the femur and systemic chemotherapy, the patient is doing well.

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