Hereditary multiple exostoses

Case contributed by Dr Domenico Nicoletti


Right shoulder mass for several years without any pain.

Patient Data

Age: 12 years
Gender: Female

On plain film, there are multiple well-defined broad-based exostoses at metadiaphyseal region of the proximal humerus, continuous with the parent cortex and trabeculae. The lesions are directed away from the shoulder joint.


On MRI, the lesion arises from the lateral, medial and posterior aspect of the proximal humerus and shows cortical and medullary continuity with parent bone. A thin layer (6 mm thick) of hyaline cartilage cap of T1 low signal and T2 high signal is seen.

Case Discussion

MRI is the best imaging modality to demonstrate cortical and medullary continuity between the osteochondromas and parent bone. On MRI, thin hyaline cartilage cap of low to intermediate signal on T1 sequence and high signal on T2 sequence reflects its high water content. When there are multiple osteochondromas, the condition is termed hereditary multiple exostoses or diaphyseal aclasis.

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Case information

rID: 71376
Published: 2nd Oct 2019
Last edited: 4th Oct 2019
Inclusion in quiz mode: Included

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