Familial multiple endocrine neoplasia type 1 with intrathoracic low-grade fibromyxoid sarcoma.

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN1) is a hereditary tumor syndrome characterized by endocrine tumors with mainly a parathyroid, pancreatic, or anterior pituitary origin. Low-grade fibromyxoid sarcoma (LGFMS) is a rare low-grade soft tissue tumor. There is one known report of a patient with MEN1 complicated by LGFMS, which is very rare. Our report represents the second documented case, providing valuable insights.

CASE PRESENTATION: A 31-year-old man with the chief complaint of a cough underwent chest contrast-enhanced computed tomography, which revealed a giant hypoabsorptive tumor with a maximum diameter of 23 cm in the left thoracic cavity. The patient was diagnosed with MEN1, as he also possessed a pancreatic neuroendocrine tumor and parathyroid tumor, and because his father had been found to have MEN1. To control hypercalcemia, surgery for the parathyroid tumor was initially performed, followed by surgical resection of the giant thoracic tumor for diagnosis and treatment. Histopathological examination findings of the tumor resulted in a diagnosis of LGFMS.

CONCLUSION: We experienced a very rare MEN1 with LGFMS. Although endocrine tumors generally occur more frequently in MEN1, non-endocrine tumors such as the present case should also be noted, reinforcing the importance of systemic imaging scrutiny in addition to early diagnosis and long-term follow-up of MEN1 patients.