Surgical Pathology Criteria

Gastric Plexiform Fibromyxoma

Differential Diagnosis

GIST (spindled, bland) Gastric Plexiform Fibromyxoma
Usually solitary nodule Multinodular, plexiform
Myxoid pattern rare Myxoid pattern predominates
KIT and/or DOG1 74-95% KIT and DOG1 negative
CD34 frequently positive CD34 negative

Inflammatory Fibroid Polyp Gastric Plexiform Fibromyxoma
Usually solitary nodule Multinodular, plexiform
Usually a pedunculated polyp Intramural
Centered on submucosa Centered on muscularis propria
Frequent inflammatory infiltrate No intrinsic inflammatory infiltrate
May have concentric perivascular pattern of spindle cells Lacks concentric pattern
CD34 frequently positive CD34 negative

Plexiform Neurofibroma Gastric Plexiform Fibromyxoma
S100 positive S100 negative

GI Leiomyoma, Myxoid Gastric Plexiform Fibromyxoma
Usually contains at least focal collections or fascicles of cells with distinct eosinophilic cytoplasm Indistinct or clear cytoplasm, no fascicles
Myxoid pattern rare Myxoid pattern predominates
Desmin usually positive Desmin negative

Fibromatosis, Mesenteric or Retroperitoneal and Pelvic Gastric Plexiform Fibromyxoma
Long fascicles of cells No fascicles
Myxoid pattern rare Myxoid pattern predominates
Areas of dense collagen frequent Lacks dense collagen
Usually extrinisc mass invading bowel wall Intrinsic to bowel wall
CD117 frequently negative, variable reports of focal/weak staining CD117 74-95% positive
DOG1 negative DOG1 87-94%

Stanford Medicine Resources:

Footer Links: