Korean J Gastroenterol.  2011 May;57(5):323-326. 10.4166/kjg.2011.57.5.323.

A Case of a Retroperitoneal Schwannoma Presenting as Hypermetabolic Mass in PET-CT

• Goh PG
• Ko KH
• Kim ES
• Kim YJ
• Lee SY
• Moon HS
• Jeong HY

• KMID: 1792791
• DOI: http://doi.org/10.4166/kjg.2011.57.5.323

Abstract

Schwannoma is a benign neoplasm of the Schwann cells of the neural sheath. Most schwannomas occur in the head and neck, and extremities and rarely in the retroperitoneal space. The differentiation of a schwannoma from other malignant tumor or benign tumor is very difficult on a preoperative examination with ultrasonography, computed tomography or magnetic resonance imaging. Furthermore, the lesion with increased fluorodeoxyglucose uptake in PET-CT cannot exclude malignant tumor. Therefore, this lesion needs surgical excision and a histological examination with immunohistochemical staining. We report a case of schwannoma occuring in the retroperitoneal space that incidentally discovered by PET-CT for health-check up. Pathologic confirmation by laparoscopic excision was done.

Keyword

Schwannoma; PET-CT

MeSH Terms

Aged
Diagnosis, Differential
Fluorodeoxyglucose F18/diagnostic use
Humans
Male
Neurilemmoma/*diagnosis/pathology/surgery
Positron-Emission Tomography
Retroperitoneal Neoplasms/*diagnosis/pathology/surgery
Tomography, X-Ray Computed

Figure

• 

  Fig. 1. PET-CT finding. On left pelvic area, hypermetabolic mass (max SUV 3.7) (arrow) with increased FDG uptake was seen.

• 

  Fig. 2. Abdominal CT finding (enhanced image). Focal target-like mass (about 3×2 cm) (arrow) in adjacent to left pelvic bone was seen.

• 

  Fig. 3. Microscopic finding. It showed bundles of compact spindle cells which were surrounded by loose myxoid areas (H&E stain, ×100).

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  Fig. 4. Immunohistochemical staining.(A) It showed tumor cell negative for c-kit (c-kit stain, ×200). (B) Immunohistochemical stain for S-100 protein showed that tumor cells were positively statined (brown color) (S-100 protein stain, ×200).

Reference

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