Omental malignant fibrous histiocytoma with a unique rough endoplasmic reticulum inclusion.
The laminated inclusions in the rough endoplasmic reticulum (RER) are peculiar structures seen only in some cases of chondrocytes of pseudoachondroplasia. These ultrastructurally unique organelles have not yet been reported in inflammatory malignant fibrous histiocytoma (MFH). We describe an omental mass showing unique laminated inclusions in the RER in a young man with intra-abdominal inflammatory MFH. The most striking ultrastructural feature was a dilated RER containing a fine granular substance and a more electron-dense material exhibiting an onion skin-like lamellated or maze-like pattern, mimicking that of so-called laminated inclusions. These lamellated inclusions occupied most of the cytoplasm of the tumor cells. We speculate that the ultrastructural finding of the laminated RER inclusion is not specific for cartilage cells, but may represent abnormal accumulation of some kind of glycoprotein material or matrix protein. This granular material may undergo organization to form a peculiar laminated structure, probably due to a metabolic or fixation process. Further study is needed to elucidate the nature of this material.
Park
Moon Hyang
MH
Department of Pathology, Hanyang University, College of Medicine, Seoul, Korea. parkmh@hanyang.ac.kr
Jeon
Seok Hoon
SH
Kim
Nam Hoon
NH
Kang
Moon Ja
MJ
D000328:Adult; D014408:Biomarkers, Tumor / Q000032:analysis; D003131:Combined Modality Therapy; D018870:Endoplasmic Reticulum, Rough / Q000648:ultrastructure*; D017809:Fatal Outcome; D018219:Histiocytoma, Benign Fibrous / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D009852:Omentum / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology*; D010534:Peritoneal Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000628:therapy; D014057:Tomography, X-Ray Computed
D014408:Biomarkers, Tumor