Journal of Medical Cases, ISSN 1923-4155 print, 1923-4163 online, Open Access
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Case Report

Volume 16, Number 2, February 2025, pages 48-54

An Unusual Case of Extracavitary/Solid Variant Primary Effusion Lymphoma With Associated Hemophagocytic Lymphohistiocytosis

Figures

↓  Figure 1. CT of the chest with contrast demonstrating an 8.7 × 7.1 × 4 soft tissue mass extending along the middle and posterior mediastinum into the left hilum (arrow). The lesion is exerting mass effect on the left atrium, encasing several pulmonary veins, and effacing the fat plane along the anterior esophagus with esophageal wall thickening. CT: computed tomography.
Figure 1.
↓  Figure 2. CT thorax with contrast demonstrating a large pleural effusion occupying the majority of the left hemithorax (arrows). CT: computed tomography.
Figure 2.
↓  Figure 3. Primary effusion lymphoma. (a) Sheets of large pleomorphic lymphoma cells with prominent nucleoli and abundant cytoplasm, morphologically consistent with EC-PEL (H&E stain, original magnification: × 400). (b) Cytospin smear of pleural fluid showing PEL (Wright-Giemsa stain, original magnification: × 600). (c) Strong positive immunostaining for CD138 in neoplastic cells (immunohistochemistry, original magnification: × 400). (d) Strong positive immunostaining for MUM-1 in neoplastic cells (immunohistochemistry, original magnification: × 400). (e) The lymphoma cells demonstrate strong positive immunostaining for HHV8 (immunohistochemistry, original magnification: × 400). (f) Weak positive immunostaining for CD45 in neoplastic cells (immunohistochemistry, original magnification: × 400). (g) A small subset of neoplastic cells showed positive immunostaining for CD3 (immunohistochemistry, original magnification: × 400). (h) In situ hybridization for EBER was positive in the lymphoma cells (original magnification: × 400). EBER: Epstein-Barr virus-encoded RNA; EC-PEL: extracavitary primary effusion lymphoma; H&E: hematoxylin and eosin stain; PEL: primary effusion lymphoma.
Figure 3.

Tables

↓  Table 1. Patient HScore
 
Criteria Present case Points
HIV: human immunodeficiency virus; AST: aspartate aminotransferase.
Known underlying immunosuppression Yes (HIV positive) 18
Temperature 38.9 °C 33
Organomegaly Hepatomegaly and splenomegaly 38
Number of cytopenias 3 lineages 34
Ferritin 14,134 ng/mL 50
Triglycerides 298 mg/dL 44
Fibrinogen 264 mg/dL 0
AST 165 19
HScore (total points) 236
Probability of hemophagocytic syndrome based on HScore 98-99%

 

↓  Table 2. HLH-2004 Criteria in Present Case
 
Criteria Present case
HLH: hemophagocytic lymphohistiocytosis; IL: interleukin.
Fever Yes (38.9 °C)
Splenomegaly Yes
Cytopenia (affecting ≥ 2 of 3 lineages in peripheral blood) Yes
Hypertriglyceridemia and/or hypofibrinogenemia (fasting triglycerides > 3.0 mmol/L (> 265 mg/dL) or fibrinogen ≤ 1.5 g/L) Triglycerides: 298 mg/dL
Hemophagocytosis in bone marrow, spleen, liver, lymph nodes, or other tissues Not identified in bone marrow aspirate
Low or absent natural killer (NK) cell activity Not measured
Serum ferritin concentration ≥ 500 µg/L 14,134 µg/L
Soluble CD25 (soluble IL-2 receptor) ≥ 2,400 U/mL 39,950 U/mL
Number of criteria fulfilled 6 out of 8 (at least 5 criteria needed to fulfill HLH diagnosis)