PRIMARY MALIGNANT LYMPHOMA OF THE STERNUM

Clinical History

Anterior chest wall mass

Imaging Findings

The patient was referred to our hospital because of two-month history of anterior chest wall mass, without pain and no fever. Physical examination revealed a anterior chest mass. Enhanced CT scan showed a homogeneous soft-tissue-density mass, 2 x 3 x 4,5 cm in size, arising from the sternum (fig 1). The mass destroyed the sternum without extension into the subcutaneous tissues, or mediastinal space (fig 2). There were no pulmonary lesions or mediastinal nodes. Sternocostal joints were intact. A bone tumour or infection were suspected. No further lesions were detected by bone scintigraphy. The patient underwent an open surgical biopsy. Histology revealed a malignant non-Hodgkin lymphoma classified as diffuse large B-cell lymphoma. Therapy consisted of 6 CHOP cycles, followed by radiotherapy. After therapy there was a complete regression of the disease. The most interesting aspect of this case is involvement of the sternum as the solitary manifestation of the primary malignant lymphoma.

Discussion

Primary non-Hodgkin bone lymphoma (NHL) is a rare condition which represents a low percentage of both the malignant primary bone tumours and non-Hodgkin extranodal lymphoma. Patients with primary NHL of bone commonly present with local bone pain, soft tissue swelling, and a mass or a pathological fracture. There is a slight male preponderance, and most patients are over 45 - 50 years of age (1). Primary NHL of bone can arise in any part of the skeleton, but long bones are the most common sites of presentation. To our knowledge, this is the first case of solitary primary malignant non-Hodgkinien lymphoma of sternum in the English literature. Plain radiographs often revealed osteolysis or osteosclerosis lesion (2). Computed tomography studies are more sensitive than plain radiographs, lesions appear radiolucent, permeative or destructive, with or without sclerosis, and demonstrate a soft-tissue mass. Magnetic resonance imaging of the primary lesion demonstrates low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, and is more sensitive than computed tomography for detecting a soft-tissue mass (2). Primary bone lymphoma is highly curable with a combination of chemotherapy and radiotherapy (3).

Differential Diagnosis List

Final Diagnosis

Sternal primary malignant lymphoma

URL:	https://www.eurorad.org/case/4949
DOI:	10.1594/EURORAD/CASE.4949
ISSN:	1563-4086