Amputation neuroma mimicking lymph node metastasis of remnant gastric cancer: a case report

Abstract

Background: Amputation neuromas (ANs) are reactive hyperplasia of nerve tissues that occur after a trauma or surgery involving the peripheral nerves. Only two previous reports of ANs occurring around the stomach and post gastrectomy have been reported. We report the case of a patient with AN near the remnant stomach who underwent distal gastrectomy for gastric cancer.

Case presentation: A 76-year-old man underwent distal gastrectomy, D1+ lymphadenectomy, and Billroth-I reconstruction for early gastric cancer in another hospital at 63 years of age. A regular gastrointestinal endoscopic follow-up examination after gastrectomy revealed an ulcerative lesion on the lesser curvature of the remnant stomach, which was diagnosed as remnant gastric cancer based on the histopathological examination. Then, he was transferred to our hospital. An upper gastrointestinal series and endoscopy revealed an 18-mm Type 0-IIc lesion on the lesser curvature of the remnant stomach with an estimated depth within the mucosa (T1a). An abdominal contrast-enhanced computed tomography (CT) failed to detect the primary lesion; however, a slightly enhanced 13 × 10-mm nodule was detected near the lesser curvature of the remnant stomach. An endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) of the nodule showed no cancer cell; thus, endoscopic submucosal dissection (ESD) for the remnant gastric cancer was performed. Histopathological examination revealed noncurative resection due to T1b2 and UL (+). We planned an additional surgical resection. Before the resection, CT was performed, which had a 3-month interval with a previous CT, showing an enlargement of the nodule to 16 × 12 mm. We diagnosed the nodule as a lymph node metastasis and performed resection of the remnant stomach, D2 lymphadenectomy, splenectomy, and Roux-en-Y reconstruction. The nodule was later diagnosed as AN based on the histopathological examination. There was no residual cancer in the resected specimen.

Conclusions: We report AN mimicking lymph node metastasis near the remnant stomach of a patient with remnant gastric cancer. When nodules appear in the previous operative field, the possibility of ANs should be considered, although the incidence may be quite low.

Keywords: Amputation neuroma; Gastrectomy; Gastric cancer; Lymph node metastasis; Remnant stomach; Traumatic neuroma.

Fig. 1

An abdominal contrast-enhanced computed tomography a before endoscopic submucosal dissection (ESD) and b 1.5 months after ESD. a Abdominal contrast-enhanced computed tomography shows a nodule lesion with slight contrast near the remnant stomach (arrow). b The nodule lesion increased in size over 3 months (arrow head)

Fig. 2

Endoscopic ultrasonography image of the nodule. An endoscopic ultrasonography shows a hypoechoic lesion without vascular flow. The margin of the lesion was slightly indistinct (arrows)

Fig. 3

Macroscopic findings of the resected specimen. Macroscopically, the nodule suspected as lymph node metastasis was relatively well defined but did not have a clear capsule

Fig. 4

Histopathological findings. Thick nerve fibers without atypia proliferated with a bundle-like or spiral pattern. Hematoxylin–eosin staining. a × 20 and b × 100