Rare case of granular cell tumor of perianal region: a case report and literature review

Abstract

Granular cell tumors (GCTs) are rare submucosal neoplasms, with tumors in the oral mucosa accounting for about a third of all cases. In contrast, GCT is a rare anal neoplasm, with fewer than 30 cases of perianal GCT reported in the literature. We report the case of a 36-year-old woman with a perianal lump with no obvious local lesion as the main clinical complaint. The tumor was completely resected and histologically confirmed as a GCT. The patient remained under continuous follow-up. GCT is difficult for surgeons and pathologists to diagnose, and biopsy and immunohistochemical analysis are prerequisites for an accurate diagnosis. An integrated understanding of GCT in terms of its differential diagnosis will contribute to better identification and more appropriate treatment of this disease.

Keywords: Granular cell tumor; anal neoplasm; biopsy; differential diagnosis; immunohistochemistry; perianal region.

Figure 1.

Perianal mass with pressing pain at 7 o’clock direction.

Figure 2.

Results of perianal ultrasound showing a hypoechoic mass with clear edges (red arrow) approximately 3.07 cm × 2.24 cm in size.

Figure 3.

Gross appearance of tumor after complete resection.

Figure 4.

Histological staining and immunostaining of the tumor after complete resection. (a) Hematoxylin and eosin-staining. Immunostaining for (b) S-100, (c) neuron-specific enolase, (d) vimentin, (e) Ki-67 (darker portion indicates positive expression), and (f) AE1/AE3. (All × 2). Scale bars = 20 μm.