CASE HISTORY
Imaging studies
Imaging studies
This 16-year-old girl from Ecuador presented with pain on her right shoulder. Imaging studies revealed a large lytic (destructive) lesion of her right distal clavicle.
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Imaging studies
Histopathology
An initial biopsy was performed, followed by an excision, which showed a destructive, extensively hemorrhagic bone lesion with substantial new bone formation at the periphery. In view of its destructive nature and extensive new bone formation, after thorough review, the lesion was diagnosed as an osteosarcoma, a malignant primary tumor of bone, and chemotherapy was scheduled. The patient's mother, through a friend, sought a second opinion, and the case was sent to Dr. Zambrano for second review, courtesy of Dr. Luis Eduardo Fayad (Hemato-oncologist at MD Anderson Cancer Center).
Histopathology
Imaging studies
Histopathology
On low power view, we see areas of hemorrhage (in red), fibrosis (pink) and increased cellularity (purple), with extensive new bone formation (trabeculae on top).
Histopathology
Histopathology
Histopathology
On intermediate power view, we see areas of hemorrhage (in red) and increased cellularity (purple), with extensive new bone formation (trabeculae on right lower corner). These areas of bone formation were initially interpreted as being malignant.
Histopathology
Histopathology
Histopathology
On high power view, we see areas of hemorrhage (in red) and marked cellularity, including abundant multinucleated osteoclast-type giant cells.
Histopathology
Fluorescent in-situ hybridization (FISH)
In view of its histomorphologic appearance, a diagnosis of aneurysmal bone cyst was strongly favored, and confirmatory molecular studies by Fluorescent in-situ hybridization (FISH) were performed.
Fluorescent in-situ hybridization (FISH)
Fluorescent in-situ hybridization (FISH)
Fluorescent in-situ hybridization (FISH)
FISH showed a translocation involving the USP6 gene region in 17p13.2, commonly seen in aneurysmal bone cyst, among other benign soft tissue lesions.
Fluorescent in-situ hybridization (FISH)
Based on these histopathological and molecular results, the lesion was reclassified as an aneurysmal bone cyst, a benign tumor of bone, which in spite of its locally destructive nature, it does not have metastatic potential and does not require chemotherapy, sparing this young girl of its potentially toxic side effects, while providing her and her family with the peace of mind of a benign diagnosis.