Granular cell tumor in the ascending colon

Area of Science:

• Gastroenterology
• Surgical Pathology
• Oncology

Background:

• Granular cell tumors (GCTs) are rare neoplasms typically arising in the tongue but can occur in various locations.
• Colonic GCTs are exceptionally rare, and multiple synchronous GCTs are even rarer.

Observation:

• A 62-year-old male presented with multiple polypoid lesions in the colon.
• Barium enema identified eight lesions; five were subsequently examined histologically.
• A submucosal nodule in the ascending colon exhibited characteristic GCT morphology.

Findings:

• Histological examination revealed nested growth of large cells with granular cytoplasm and round nuclei, consistent with GCT.
• Immunohistochemical analysis showed tumor cell positivity for S-100, neuron-specific enolase, and vimentin.
• Tumor cells were negative for smooth muscle markers (alpha-smooth muscle actin and desmin), supporting a neural crest origin.

Implications:

• This case expands the understanding of GCT presentation in the colon, highlighting the possibility of multiple lesions.
• Accurate diagnosis through histology and immunohistochemistry is crucial for appropriate management of colonic GCTs.
• Further research into the etiology and behavior of multifocal GCTs in the gastrointestinal tract is warranted.