Nonepiphyseal Giant Cell Tumor of the Rib: A Case Report

Table 1

Differential diagnosis of a well-defined lytic lesion of the rib (based on [3, 9, 12, 13]).

Tumor name	Patient age	Rib location	Imaging pattern
Benign
Fibrous dysplasia (monostotic)	Most patients: 20–30 years old	Common	May cause cortical thickening and exhibit amorphous calcification or ground glass appearance.
Enchondroma	2nd–5th decade of life	Common	Expansile lytic lesion, which may have calcified cartilaginous matrix. Usually located at the costochondral or costovertebral junction.
Eosinophilic granuloma	Most cases seen before the age of 30	Common	Solitary lytic lesion. A sclerotic margin may be present in the healing phase.
Brown tumor	Depends on the age of development of hyperparathyroidism	Rare	May be identical to GCT on imaging and histology. Laboratory tests should confirm hyperparathyroidism.
Aneurysmal bone cyst	Most cases seen before the age of 30	Rare	Expansile lesion which may exhibit bone destruction and extension into adjacent soft tissue. Fluid-fluid levels commoner than in GCT.
Simple bone cyst	Most cases seen before 20 yrs	Rare	Ovoid lytic lesion, often with a fine sclerotic margin.
Chondromyxoid fibroma	Less than 30 yrs	Rare	Well-marginated masses with scalloped sclerotic borders. No internal calcification. Possible cortical expansion.
Malignant
Metastasis	Commoner after 50 yrs	Common	Well- or ill-defined osteolysis without sclerotic rim. Most common primaries: lung and breast.
Solitary myeloma	Mean age: 50 yrs	Common	Well-defined, “punched out” lytic lesion, which may cause expansion. No sclerotic margin.
Chondrosarcoma (low grade)	Most cases seen after 50 yrs	Common	Better differentiated tumors are well defined. Arc-like, stippled, or amorphous calcification is common.