A 57-year-old male was admitted to hospital with "lower abdominal pain for 10 days", and a strip-shaped hard mass was palpable on the right side of the lower abdomen. Abdominal enhanced CT (Figure 1): Subcutaneous soft tissue space-occupying lesions in the anterior abdominal wall of the lower abdomen, considering the possible origin of anterior abdominal wall muscles. Abdominal wall tumor resection was performed. Postoperative pathology (Figure 2): malignant spindle cell tumor, consistent with malignant peripheral schwannoma, focal with rhabdomyoblast differentiation and ossification, immunohistochemistry: Vim (+), CD99 (+), Desmin (focal +), CD34 (-), SMA (-), STAT-6 (-), CK (-), S-100 (-), SOX-10 (-), H3K27me3 (deletion), β-catenin (-), MyoD1 (-), Myogenin (-), Ki67 (+,>40%). Two months after discharge, the tumor recurred and enlarged tumor resection, radiotherapy was given after operation, and it recurred again three months later. PET-CT considered multiple metastases, and performed "laparoscopic abdominal exploration + partial small intestine resection + abdominal wall tumor resection". Postoperative pathology: malignant tumor was found on the intestinal serosa surface, tending to malignant schwannoma, invading the whole thickness of intestinal wall; Malignant schwannoma of the abdominal wall was seen subcutaneously. Two months after surgery, the patient was readmitted to the hospital due to "abdominal pain and abdominal distension for 1 d". CT of the lower abdominal wall (Figure 3) showed multiple soft tissue shadows in the right lower abdomen, which were significantly larger than before. Tumor recurrence/metastasis and intestinal obstruction were considered. Symptomatic treatment was given for relief. One month later, "exploratory laparotomy + abdominal tumor resection + partial small intestine resection + partial ascending colon resection" was performed. The postoperative pathology still considered malignant schwannoma, and the chemotherapy with eribulin mesylate was given, but the effect was poor. One month later, the patient was readmitted to the hospital due to "abdominal pain and abdominal distension", and the diagnosis was: digestive tract perforation, massive abdominal and pelvic fluid effusion and peritonitis possible; Tumor recurrence/metastasis of right lower abdominal cavity and abdominal wall, intestinal obstruction. He died after 2 days of symptomatic conservative treatment.
