# ‘Malignant granular cell tumor of the Appendiceal orifice: a rare case and review of literature’

**Authors:** Omer Usman, Muhammad Waqas Khan, Maham Tariq, Muhammad Usman Shahbaz, Marwa Javed Warriach, Muhammad Abdul Basit, Hassan Shah Aryani

PMC · DOI: 10.1093/omcr/omaf190 · Oxford Medical Case Reports · 2025-10-22

## TL;DR

A rare case of malignant granular cell tumor at the appendiceal orifice is reported, highlighting the need for early detection and surgical intervention.

## Contribution

This paper presents a rare clinical case of malignant GCT in the colon and emphasizes its management.

## Key findings

- A 37-year-old woman was diagnosed with a malignant granular cell tumor at the appendiceal orifice.
- Surgical resection with clear margins was performed, and histopathology confirmed malignancy.
- The case underscores the importance of early detection to prevent severe outcomes in malignant GCTs.

## Abstract

Granular cell tumors (GCTs) are rare, mostly benign soft-tissue neoplasms, with only 8% occurring in the gastrointestinal tract, making the colon an uncommon location. We present the case of a 37-year-old Hispanic woman who underwent a screening colonoscopy due to a family history of colon cancer. A submucosal nodule at the appendiceal orifice was resected, and a biopsy revealed a malignant GCT, confirmed by S100-positive staining. The patient underwent a right hemicolectomy, with the resection showing a 2 mm focus of granular cell tumor with clear margins. Histopathology confirmed malignancy, with additional findings of reactive hyperplasia of mucosa-associated lymphoid tissue and focal ileitis. Although rare in the colon, malignant GCTs carry a high risk of mortality and recurrence. Small lesions (< 1 cm) can be monitored, but larger or malignant ones require surgical resection. Our case emphasizes the importance of early detection and intervention to prevent severe outcomes in malignant GCTs.

## Linked entities

- **Proteins:** S100A1 (S100 calcium binding protein A1)
- **Diseases:** colon cancer (MONDO:0002032)

## Full-text entities

- **Genes:** S100A1 (S100 calcium binding protein A1) [NCBI Gene 6271] {aka S100, S100-alpha, S100A}
- **Diseases:** ileitis (MESH:D007079), colon cancer (MESH:D015179), malignancy (MESH:D009369), hyperplasia (MESH:D006965), GCTs (MESH:D016586), GCT (MESH:C537296)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

10 references — full list in the complete paper: https://tomesphere.com/paper/PMC12542983/full.md

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Source: https://tomesphere.com/paper/PMC12542983