Fatal abdominal hemorrhage following surgery to remove a retroperitoneal MPNST associated with NF1: A case report.

Individuals diagnosed with neurofibromatosis type I (NF1) commonly present with neurofibromas, and a subset may progress to develop malignant peripheral nerve sheath tumors (MPNST) during their lifetime. Diagnosing and treating MPNST, typically linked to NF1, poses challenges for clinicians due to its histopathological complexity. A 25-year-old male presented with postprandial discomfort and vomiting, subsequently developing left mid-abdominal pain. The patient was admitted to the hospital, where a low-density retroperitoneal mass was detected via computed tomography (CT). Histopathological examination revealed spindle-shaped tumor cells characterized by abundant cytoplasm and highly pigmented nuclei, demonstrating pathological nuclear division. The tumor cells exhibited partial cytoplasmic positive for S-100 and focal cytoplasmic positive for cytokeratin (CK) and desmin, as determined by immunohistochemical staining. Genetic analysis of blood and extracted tissues identified an NF1 missense mutation. Prior research corroborated the pathological diagnosis of MPNST exhibiting both epithelial and myogenic differentiation. A retroperitoneal mass excision was conducted, revealing a mass located in the retroperitoneal omental sac. Approximately 5 hours after surgery, the patient's blood pressure exhibited a gradual decline. An emergency laparotomy was conducted. Approximately 3000 mL of blood was identified in the upper abdominal cavity. The patient's blood pressure consistently declined and ultimately resulted in death after 2 days. It is crucial to assess the potential for heterogeneous differentiation in MPNST during pathological diagnosis. In the treatment of MPNST with heterogeneous differentiation, particularly in cases with significant tumor bulk, surgeons must anticipate potential hemorrhagic complications and adopt a cautious approach to surgical intervention.