Transverse colon foreign body-associated reactive mass mimicking gastrointestinal stromal tumors: A case report

Table 1 Timeline of clinical events

Time point	Event	Details
20 years prior	Open appendectomy	Performed for perforated appendicitis with peritonitis; no subsequent symptoms for two decades
Screening period	Screening chest CT	Incidentally detected a 9-10 cm intra-abdominal mass; patient asymptomatic
Diagnostic evaluation	Contrast-enhanced abdominal CT	Well-circumscribed mass with central low attenuation and peripheral enhancement, strongly suggestive of a GIST
Day of surgery	Exploratory laparotomy	Dense adhesions present; mass originated from the transverse colon rather than the small bowel
Same operation	Segmental transverse colectomy	Mass and involved colon resected; stapled functional end-to-end anastomosis performed
Postoperative day 7	Initial discharge	Early recovery uneventful
Postoperative day 8	Readmission	Nausea and vomiting; imaging suggested postoperative ileus; managed conservatively
Postoperative day 13	Final discharge	Symptoms resolved; no further complications
Postoperative pathology	Final diagnosis	Well-circumscribed 9.7 cm × 8.0 cm × 7.5 cm subserosal mass arising from the transverse colon; unilocular cystic lesion with a thick fibrous capsule, containing necrotic debris and old hemorrhage. No epithelial lining or neoplastic cells identified. Histology demonstrated cholesterol crystals and chronic foreign body-type inflammatory reaction, with PAS-positive irregular foreign materials detected microscopically, despite no grossly identifiable foreign material

CT: Computed tomography; GIST: Gastrointestinal stromal tumor.

Table 2 Reported cases of foreign body-associated reactive masses mimicking tumors

Ref.	Age (year)/sex	Symptoms	Preoperative imaging	Initial suspected diagnosis	Surgical method	Prior surgery and interval
Papaoikonomou et al[1]	42/female	Incidental finding	CT	GIST	Mass resection	Cesarean section, approximately 20 years
Han et al[2]	33/female	Vomiting	CT	Jejunal tumor (GIST)	Laparoscopy-assisted resection	Cesarean section, 7 years
Gaylard et al[7]	Adult	Asymptomatic PET-positive lesion	PET-CT	Lymphoma recurrence	Excisional resection	Appendectomy, 56 years
Itoh et al[6]	74/male	Incidental nodules	CT, PET-CT	Peritoneal metastasis	Liver + peritoneal nodule resection	Low anterior resection, 1.5 years
Celik et al[3]	Adult	Abdominal/pelvic mass	CT	Soft-tissue tumor	Laparotomy + mass excision	Abdominal surgery (unknown interval)
Hajri et al[8]	65/female	Nausea, vomiting	CT	GIST	Segmental hepatectomy	Cholecystectomy, 29 years
Zhang et al[4]	Female	Adnexal mass symptoms	CT	Ovarian teratoma	Mass excision + bowel resection	Abdominal surgery (unknown interval)
Oran et al[10]	28/female	Epigastric mass	CT	Serous cystadenocarcinoma	Laparotomy + mass removal	Cholecystectomy, 3 years
Oran et al[10]	36/female	Abdominal mass	CT	Ovarian/adnexal tumor	Laparotomy + mass removal	Cesarean section, (unknown interval)
Eken et al[9]	62/female	Abdominal discomfort	CT, MRI	Mesenchymal tumor	Mass resection	Prior abdominal surgery (unknown interval)
Fumimoto et al[11]	77/male	Asymptomatic	CT	Lymphoma vs sarcoma	Image-guided biopsy → conservative	NBCA embolization, 12 months

CT: Computed tomography; GIST: Gastrointestinal stromal tumor; PET-CT: Positron emission tomography-computed tomography; MRI: Magnetic resonance imaging; NBCA: N-butyl-2-cyanoacrylate (embolization material).