Giant costal osteochondroma in a man with multiple exostoses

Area of Science:

• Orthopedics
• Oncology
• Genetics

Background:

• Multiple familial osteochondromatosis (MFOC) is a rare genetic disorder characterized by multiple benign bone tumors.
• Malignant transformation of osteochondromas, though uncommon, is a known complication, often presenting as chondrosarcoma.

Observation:

• A 42-year-old male with MFOC presented with a massive, symptomatic left fourth rib osteochondroma (56x47x33 cm) causing kyphosis.
• The patient also had multiple osteochondromas on his legs and a family history suggestive of hereditary transmission.

Findings:

• The large costal osteochondroma showed signs of malignant transformation.
• Histopathological examination confirmed chondrosarcoma arising from the osteochondroma.
• Surgical resection of the tumor led to symptom relief and no recurrence at 16 months.

Implications:

• This case underscores the potential for malignant transformation in large osteochondromas, even in the context of familial disease.
• Early detection and complete surgical excision are crucial for managing symptomatic and potentially malignant osteochondromas.
• Genetic counseling and long-term surveillance are important for patients with multiple familial osteochondromatosis.