Synchronous multiple primary cancer. Bone non-Hodgkin lymphoma and breast invasive ductal carcinoma

Clinical History

Patient presented with a 2-month history of painful left leg swelling. Past medical history was unremarkable. Physical examination showed a painful soft-tissue mass in the left leg. There were neither any other systemic symptoms nor lymphadenopathy. Laboratory tests were normal.

Imaging Findings

Anteroposterior radiograph showed an osteolytic lesion with a moth-eaten appearance involving medullary cavity and cortex in proximal metadiaphysis of left tibia (Fig. 1). MR imaging demonstrated bone marrow replacement in proximal metadiaphysis of left tibia with adjacent soft-tissue mass and permeated cortical bone (Fig. 2). Thoracic, abdominal and pelvic CT showed a soft-tissue right breast mass (Fig. 3). There was neither abnormal lymphadenopathy nor visceral involvement on CT. Mediolateral oblique mammogram showed a mass with spiculated margins at 6 o’clock in the right breast at the anterior depth (Fig. 3).
Ultrasound-guided needle core biopsy of the left leg soft-tissue mass demonstrated a high-grade, diffuse, large B-cell lymphoma with CD79a+ and CD 20+ phenotypes (Fig. 4). Bone marrow examination was normal. Ultrasound-guided needle core biopsy of the right breast lesion demonstrated an invasive ductal carcinoma, not otherwise specified (NOS) with E-cadherin positive immunoreactivity (Fig. 5). Axillary surgical assessment was negative.

Discussion

Multiple primary cancer (MPC) is a specific malignant tumour type, manifesting as more than one primary tumour diagnosed in the same patient, either simultaneously or sequentially [1]. Synchronous multiple primary cancer (SMPC) is defined as two or more tumours occurring within an interval of six months [1, 2]. The reported incidence of SMPC is rare (0, 8%), and it is even less common to observe synchronous solid tumours with a haematological malignancy [2]. Factors that have been suggested as contributing to the development of synchronous malignancies include advanced age of the patient, primary or cancer-related immunological impairment and genetic predisposition to cancer [1-3]. Although it is both impractical and unnecessary to obtain biopsies for every lesion that may appear in a case of MPC [4], awareness of the different biological behaviours between solid tumours and haematologic malignancies should be considered. The treatment choice depends on the tumour location and may involve curative surgical resection of each cancer, radiotherapy, and chemotherapy [2, 3].
Primary bone lymphoma (PBL) is a rare tumour, accounting for less than 1% of all non-Hodgkin lymphomas [5, 6]. Almost all tumours are localised in long bones, and patients present with pain and/or a palpable mass. Patterns of radiographic findings of PBL have varied from near-normal to be predominantly lytic, sclerotic, or mixed lytic-sclerotic. On MR imaging, osseous destruction is variable. It was stated that a tumour with relative preservation of the cortex in the presence of a large extraosseous tumour is likely to be lymphoma. MR imaging may show small linear foci of intermediate or high signal intensity on T2-weighted sequences, penetrating the cortical bone [6].
The patient in our case was found to have an invasive ductal carcinoma-NOS at staging CT.
When one or more suspicious skeletal lesions are discovered in a patient with a known primary malignancy, the lesions are often assumed to represent skeletal involvement by the patient's known malignancy. However, solitary bone metastatic disease at the time of diagnosis of primary breast cancer is distinctly unusual. Bone breast metastases are often osteoblastic, usually involve multiple sites and extension into the adjacent soft tissues is rare. These features are considered useful to distinguish between primary and metastatic malignant lesions [7]. The possibility, although rare, of primary bone disorders like lymphoma should be kept in mind particularly when the marrow bone tumour is surrounded by soft-tissue masses but without extensive cortical destruction.

Differential Diagnosis List

Final Diagnosis

Synchronous primary bone non-Hodgkin lymphoma and breast invasive ductal carcinoma

URL:	https://www.eurorad.org/case/11153
DOI:	10.1594/EURORAD/CASE.11153
ISSN:	1563-4086