Presentation
Two-month history of dry cough and orthopnea.
Patient Data
Both lungs show diffuse smooth interlobular septal thickening , peribronchovascular interstitial thickening with centrilobular & branching nodular opacity. There are coalescing subpleural areas of consolidation associated with mild traction bronchiectasis.
Small pericardial effusion.
Both kidneys shows diffuse enhancing perinephric soft tissue thickening extending to the renal pelves and encasing the renal vessels and pelvicalyceal systems. Both adrenal glands are encased by soft-tissue.
Bone windows shows symmetrical sclerosis in the pelvis and both femora.
Diffuse thickening of myocardium of right atrium, right ventricle and right AV groove showing late gadolinium enhancement.
Small pericardial effusion.
HISTOLOGY:
MICROSCOPIC EXAMINATION:
Biopsy comprises cores of tumor tissue composed of foamy histiocytes admixed with mononuclear plump spindled histiocytes dispersed in a fibrocollagenous stroma. Interspersed neutrophils & multinucleate giant cells (including touton giant cells) are noted. These cells have small conspicuous nucleoli. No definite nuclear grooving identified. Thin walled vasculature is seen throughout the tumor. Mitosis is scarce.
ON IMMUNOHISTOCHEMISTRY :Tumor cells express LCA, CD68, CD163, CD14 while negative for CK, S100, ALK & CD1a. MIB 1 labeling index is low (2-3%). Immunostain for BRAFV600E is positive in neoplastic cells.
Case Discussion
Erdheim-Chester disease (ECD) is a rare form of non-Langerhans cell histiocytosis with multiorgan involvement which is characterized by xanthogranulomatous infiltration of foamy histiocytes in a fibrocollagenous stroma.
This case shows perirenal, periadrenal, pericardial and pulmonary involvement, as well as axial skeletal involvement and pulmonary manifestations of Erdheim-Chester disease (ECD).
The differential diagnosis of this pattern of involvement includes lymphoma.