PMC5541758_01
Abdominal computed tomography showing peritoneal carcinomatosis, including omental caking (arrows), scattered peritoneal nodularity, and ascites.
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F1
Abdominal computed tomography (CT) imaging suggested peritoneal carcinomatosis (given the omental caking and peritoneal nodularity) and showed ascites and nodularity of the liver suggestive of cirrhosis (Figure 1).
Erdheim-Chester disease histology. (A) Hematoxylin and eosin (H&E) stain of the liver biopsy showing hepatic parenchyma infiltrated by pale histiocytes (100x). (B) High magnification of H&E stain showing foamy histiocytes (arrow) (400x). (C) Trichrome stain showing cirrhosis characterized by extensive bridging fibrosis and nodular formation (100x). (D) H&E section of peritoneal biopsy showing similar foamy histiocytes (black arrow) and a Touton giant cell (blue arrow) (400x).
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F2
Liver biopsy revealed extensive bridging fibrosis and early nodule formation (stage 4/4), attributed to nonalcoholic steatohepatitis, along with prominent bile ductular proliferation and histiocytic infiltration of the sinusoids (Figure 2).
Immunohistochemical stains on liver biopsy. (A) CD163 showing numerous positive histiocytes filling the liver sinusoids (100x). (B) CD68 showing positivity in the histiocytes (100x). (C) Factor XIIIa showing weak to strong positivity in the histiocytes (100x). (D) CD1a is negative in the histiocytes (100x).
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F3
Immunohistochemistry revealed histiocytes positive for CD163 and CD68, while factor XIIIa and S-100 were weakly positive, confirming ECD (Figure 3).