Cardiac plasmacytoma with extensive infiltration: multimodal diagnosis and therapeutic challenges. A case report

Figures

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  Figure 1. Positron emission tomography–computed tomography reveals a hypermetabolic cardiac mass (arrow) extending from the posterobasal wall of the left atrium to the ostium of the right pulmonary veins.

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  Figure 2. Transthoracic echocardiography shows a hypoechogenic mass (asterisk) occupying the posteroinferior wall of the left atrium, without pedunculation or mobile components. (A) Parasternal long-axis view. (B) Apical two-chamber view. (C) Apical four-chamber view.

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  Figure 3. Cardiac magnetic resonance depicts a large cardiac mass measuring 11 × 6.3 cm, with irregular borders and extensive infiltration of both atria and adjacent structures (arrows in B and C). Invasion of the right pulmonary vein ostium is noted, with associated narrowing of the right inferior pulmonary vein (arrow in A). On tissue characterization, the mass exhibits features suggestive of malignancy: (A) T1-weighted imaging: the mass is isointense and shows no signal suppression on fat-saturated sequences. (B) T2-weighted imaging: the mass is hyperintense, consistent with increased water content and oedema. (C) Late gadolinium-enhanced imaging: heterogeneous contrast uptake is observed, with extensive infiltration of the left atrium (asterisk).

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  Figure 4. Histopathology. (A) Dense neoplastic proliferation of atypical plasma cells. (B) Strong and diffuse immunohistochemical staining for CD138, confirming plasma cell lineage. (C) High proliferative index, with Ki-67 expression in ∼80% of tumour cells.

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  Figure 5. Comparison before and after treatment. Multimodal imaging demonstrates a marked reduction in cardiac mass size following systemic therapy. (A–C) Transthoracic echocardiography and cardiac magnetic resonance obtained before treatment show extensive infiltration of both atria and involvement of the right pulmonary vein. Positron emission tomography–computed tomography demonstrates intense fluorine-18 fluorodeoxyglucose (FDG) uptake within the cardiac mass (SUV_max 8), consistent with metabolically active tumour. (D–F) Follow-up imaging reveals significant tumour regression. Cardiac magnetic resonance shows residual thickening in the lateral wall of the right atrium (9 mm) and the inferior wall of the left atrium (6 mm). FDG uptake in the cardiac mass (posterobasal aspect of the left atrium) has decreased in both intensity and extent; however, residual metabolic activity persists (SUV_max 6).