Presentation
Non-specific abdominopelvic pain. History of recent cholecystectomy.
Patient Data
A 30 mm soft tissue density exophytic mass is noted in the ascending colon. Its attenuation values are 24 HU on pre-contrast images and increased to 67 HU on PVP images. No surrounding fat stranding or regional lymphadenopathy is noted.
The gallbladder is not seen due to prior resection.
A 28 mm thin-walled non-enhanced cyst is seen beneath the anterior abdominal wall in the right upper quadrant.
A fat-containing paraumbilical hernia is evident.
A 70 mm thick-walled cyst with a few internal septations and without enhancing solid components is noted in the right adnexa.
The patient underwent proximal colon segmental resection and histopathology, and IHC evaluation confirmed schwannoma.
In addition, right adnexal cystic lesion resection was performed for the patient and histopathology evaluation reported ovarian mucinous cystadenoma.
Case Discussion
This case demonstrates a pathology-proven ascending colon schwannoma.
Gastrointestinal schwannomas are extremely rare mesenchymal neoplasms, typically present at about the 3rd to 5th decades of life. Patients are often asymptomatic but may occasionally present with abdominal discomfort or rarely GI bleeding. The stomach is the most common location in 60-70% of cases, and the colon is the next most common location. S100 protein is strongly positive in IHC evaluation.
Gastrointestinal stromal tumor (GIST), gastrointestinal leiomyoma, and gastrointestinal tract neurofibroma are in the differential list.