Xanthomatous Inflammatory Infiltrate Involving the Spleen: An Unusual Presentation of Erdheim-Chester Disease and Review of the Literature

Abstract

BACKGROUND Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis characterized by foamy histiocytes, Touton-like giant cells, and fibrosis, typically affecting the diaphyseal and metaphyseal region of the long bones but that can involve any organ or tissue. ECD is usually associated with the BRAF V600E mutation or with other molecular mutations inserted in the MAPK cascade. CASE REPORT We present the case of a 63-year-old man with a previous history of myocardial infarction who underwent an emergency splenectomy for splenic rupture after an accidental fall. Histological examination of the spleen showed a diffuse xanthogranulomatous proliferation (CD68+, CD163+, S100-, CD1a-) with rare Touton-like giant cells in the red pulp. Based on the histologic findings, a diagnosis of ECD was made. However, skeletal involvement and BRAF V600E mutation were not detected. CONCLUSIONS Cases of non-Langerhans cell histiocytosis that are histologically consistent with ECD in unusual sites have been increasingly described. There is also anecdotal evidence for cases being associated with mutations besides BRAF V600E or with no genetic alteration and no skeletal involvement. Likewise, the spectrum of clinical and molecular features of ECD can be broader than previously considered. Furthermore, there is evidence that various phases of the disease can show different clinical presentations with distinct prognostic impact, according to the mutational spectrum. Recognizing ECD at an early stage allows more effective patient management, and pathologists and clinicians should be aware of the unusual clinical presentations of this rare condition.

Figure 1.

Contrast-enhanced computed tomography scan: (A) The coronal reformatted image (lung window) showed nonspecific peri-bronchial thickening and focal areas of parenchymal consolidation involving the lower lobes. (B) On the coronal reformatted image, there is evidence of perisplenic hematomas seen as a diffuse fluid collection surrounding the spleen, with no mass effect to adjacent parenchyma. (C) An axial image shows an irregular hypodense area caused by splenic laceration (confirmed intraoperatively) and demonstrates a focal area of high attenuation in the splenic parenchyma due to active extravasation. (D) Antero-posterior radiographs of left femur and leg show normal appearance of bone marrow and regular thickness of the cortical bone with plate osteosynthesis at the proximal-third of the tibia from a previously healed fracture.

Figure 2.

Noncontrast brain computed tomography scan shows cortico-subcortical chronic infarction of the left frontal lobe.

Figure 3.

(A) Hematoxylin 7×. Splenic parenchyma with a preserved architecture and areas of hemorrhagic extravasation and an expanded red pulp. (B) Hematoxylin 60×. In the context of an expanded red pulp, a diffuse proliferation of histiocytes with a pale staining, foamy and finely granular cytoplasm and minimal nuclear pleomorphism was seen, which was occasionally associated with scattered, multinucleated cells, resembling Touton giant cells (black arrowhead). In the background, a mixed inflammatory infiltrate composed of plasma cells, small lymphocytes, and eosinophils was recognized.

Figure 4.

(A) CD68PG magnification 60×. (B) CD163 magnification 60×. (C) Protein S100 magnification 60×.