Unusual presentation of adamantinoma with synchronous involvement of entire-lengths of the tibia and fibula in an elderly man: A case report.

INTRODUCTION AND IMPORTANCE

Adamantinoma is a rare primary low-grade malignant bone tumor with a median age of 20 to 30 years with a specific predilection to the lower 2/3rd shaft of the tibia. We present an unusual presentation of a giant adamantinoma with synchronous involvement of almost entire lengths of the tibia and fibula and extensive to the skin in a geriatric man.

CASE PRESENTATION

An elderly male patient in their late 50s presented to us with a grossly deformed left leg with a fungating mass over the left leg for 5 years. X-rays showed a lytic sclerotic lesion with a honeycomb appearance involving the entire length of the tibia and fibula. Magnetic Resonance Imaging showed a heterogeneous altered signal intensity (T1 isointense and T2 heterogeneous hyper-intense lesion) large lobulated lesion involving the entire length of the leg with lytic destruction of the entire tibia and fibula and associated remodeling. The histopathological examination revealed an Invasive tumor composed of both epithelial and mesenchymal elements. On immunohistochemistry, tumor cells were positive for D240 and negative for CD31. After confirming the diagnosis of adamantinoma of tibia and fibula radical resection of the tumor was planned and performed in the form of above-knee amputation. The patient was disease-free at 18 months of the latest follow-up and walking with the above knee prosthesis comfortably without any assistance.

CLINICAL DISCUSSION

Two morphological patterns of adamantinoma on MRI have been described, a solitary lobulated focus and a pattern of multiple small nodules in one or more foci. Our case has demonstrated the second type of morphology. Histologically, this case presented with "classical basaloid type epithelial cells embedded in osteofibrous dysplasia-like stroma."

CONCLUSION

The diagnosis of adamantinoma was based on the clinical-radiological findings and histo-morphology, and should be confirmed by immunohistochemistry for demonstrating epithelial cells. Ultra-structural analysis and Cytogenetic studies may be required in the cases of unusual presentation of these tumors. Wide local resection is the preferred treatment.