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

Volume 16, Number 11, November 2025, pages 427-433

Histoplasmosis-Associated Hemophagocytic Lymphohistiocytosis in the Setting of Granulomatosis With Polyangiitis

Figures

↓  Figure 1. Bone marrow core biopsy histopathology. (a) H&E staining at × 20 magnification showing hypercellular marrow (60% cellularity). (b) CD68 staining diffusely positive showing histiocytosis (right upper). (c) Wright-Giemsa staining at × 100 magnification showing erythrophagocytic forms and hemophagocytic forms with ingested leukocytes (lower left). (d) GMS staining showing narrow-based budding yeasts consistent with histoplasma capsulatum (right lower). GMS: Grocott-Gomori methenamine silver; H&E: hematoxylin and eosin.
Figure 1.
↓  Figure 2. Wright-Giemsa stain at × 200 (left) and × 1,000 (right) magnification showing a single histiocyte performing hemophagocytosis with ingestion of mature RBCs. RBCs: red blood cells.
Figure 2.
↓  Figure 3. GMS staining at × 40 (upper left, lower left) and × 100 (upper right, lower right) showing numerous extracellular small narrow-based yeast cells consistent with disseminated histoplasmosis. GMS: Grocott-Gomori methenamine silver.
Figure 3.

Tables

↓  Table 1. HLH-2004 Diagnostic Criteria and Patient Findings
 
Criteria Patient finding Criteria met?
HLH: hemophagocytic lymphohistiocytosis; NK: natural killer; sIL2R: soluble interleukin-2 receptor; WBC: white blood cell count.
Fever Persistent fever up to 39.7 °C Yes
Splenomegaly Marked splenomegaly on imaging Yes
Cytopenias in 2+ lineages WBC 2.1 × 109, Hgb 9.6 g/dL, platelets 71 × 109 Yes
Hypertriglyceridemia (> 3 mmol/L) and/or hypofibrinogenemia (< 1.5 g/L) Triglycerides 2.73 mmol/L, hypofibrinogenemia < 5 g/L Yes (hypofibrinogenemia)
Hemophagocytosis in bone marrow, spleen, or lymph nodes Bone marrow biopsy with hemophagocytic forms Yes
Low or absent NK-cell activity Not performed No
Hyperferritinemia (> 500 µg/L) Ferritin 12,700 µg/L Yes
Elevated soluble CD25 (sIL2R) (> 2,400 U/mL) sIL2R 10,324 U/mL Yes

 

↓  Table 2. Key Laboratory Findings Over Hospital Course
 
Test Result Reference range Hospital day
ALT: alanine transaminase; AST: aspartate aminotransferase; sIL2R: soluble interleukin-2 receptor; WBC: white blood cell count.
WBC 2.1 × 109/L 4.0 - 11.00 × 109/L 0
Hemoglobin 9.6 g/dL 12.0 - 16.0 g/dL 0
Platelets 71 × 109/L 150 - 450 × 109/L 0
AST 53 U/L 10 - 40 U/L 0
ALT 37 U/L 7 - 56 U/L 0
Ferritin 12,700 µg/L 13 - 150 µg/L 14
Triglycerides 2.73 mmol/L < 1.7 mmol/L 14
Fibrinogen < 5 g/L 200 - 400 mg/dL 14
sIL2R 10,324 U/mL < 1,033 U/mL 14