Primary Splenic Diffuse Large B-Cell Lymphoma: A Case Report

Abstract

Primary splenic lymphoma (PSL) is a rare disease and an improbable cause of splenomegaly or splenic nodules. On the contrary, splenic secondary involvement as part of an advanced lymphoproliferative disorder is more common. The authors present the case of a 49-year-old woman with a primary splenic diffuse large B-cell lymphoma (PS-DLBCL), in which the absence of other organs' involvement determined an ultrasound-guided biopsy of the spleen to achieve a definitive diagnosis. With this case the authors intend to emphasise the extensive differential diagnosis of splenomegaly, splenic nodules or infiltrates, the usefulness of splenic biopsy in establishing the diagnosis and recall a rare disease, with non-specific presenting symptoms, in which the diagnostic workup is challenging.

Learning points: The differential diagnosis of splenic nodules or infiltrates is vast and challenging, and it includes haematological diseases, systemic infectious diseases but also non-malignant infiltrative diseases.Although some lymphomas frequently present with splenomegaly, this is not the case of DLBCL, with the exception of PS-DLBCL.PS-DLBCL is a very rare pathology, accounting for 1% of all DLBCL and less than 1% of all NHL.

Keywords: Primary splenic lymphoma; diffuse large B-cell lymphoma; non-Hodgkin lymphoma; splenic nodules; splenomegaly.

Figure 1

Abdominal MRI showing a non-specific multinodular splenomegaly, with multiple heterogeneous and confluent nodules, with cystic/necrotic expression, the largest measuring 11×9 cm (B, arrow). A: T1 weighted MRI, B: T2 weighted MRI

Figure 2

Haematoxylin-eosin stained biopsy of the spleen showing areas of necrosis (*) and at higher magnification (x 400) revealing diffuse infiltration by neoplastic cells with large and hyperchromatic nuclei, with variably irregular nuclear contours and scant cytoplasm

Figure 3

Immunophenotype featuring a non-germinal centre subtype diffuse large B-cell lymphoma. (A) Tumour cells are diffusely positive with CD20 immunohistochemical (IHC) stain; (B) positive with BCL2; (C) negative with CD10 IHC marker; (D) most tumour cells show immunopositivity for BCL-6; (E) strong nuclear expression is noted with MUM1 IHC marker; (F) Ki67 IHC stain depicts a high proliferative index (>90%) in tumour cells (x400 each)