Endocrine Abstracts

Introduction: Multiple endocrine neoplasia type 1 is a rare inherited tumor syndrome defined most frequently by the association of primary hyperparathyroidism, gastro-entero-pancreatic tract endocrine neoplasia and anterior pituitary gland adenoma and less commonly by neuroendocrine tumor of the adrenal cortex, thymus and bronchis. Association to non-endocrine tumors affecting the skin, glial cell, smooth muscle or breast cancer has been described. As far as we know, only one case of liposarcoma associated with MEN1 has been reported. Herein, we report data from the French MEN-1 Register showing 3 cases of liposarcoma.

Case 1: Male patient born in 1973.

-Personal medical history:Removal of a cervical lipoma.

-2001:Surgery for a well differentiated liposarcoma of the left hip that was growing gradually for years.

-2007:Genetic diagnosis of MEN1 (Father with MEN1).

-2015:Subtotal parathyroidectomy after a primary hyperparathyroidism known since 2007.

The histological analysis found an aspect of hyperplasia with predominance of clear cells and presence of oncocytic foci, no suggestive sign of malignancy.

-2014:Ulcerative duodenitis due to Zollinger-Ellison Syndrom.

-2016:Right middle lobectomy for a very well-differentiated neuroendocrine carcinoma. Immunohistochmistry testing:Synaptophysin+, Chromogramine A+, TTF1-, Ki67<3%.

-No new tumor(pancreatic, pituitary, etc) at the last follow-up.

Case 2: Male patient born in 1937.

-Family history of MEN1.

-2005: Primary hyperparathyroidism treated by Subtotal parathyroidectomy(hyperplasia), removal of the fat tissue surrounding the left thymic horn and right thyroid lobectomy. Confirmation of MEN1 germline mutation.

-No MRI was performed because of claustrophobia. Normal pituitary gland function.

-August 2011:Weight loss and asthenia revealing a 16cm well differentiated retroperitoneal liposarcoma after a distal pancreatectomy, a splenectomy and a splenic flexure colectomy was performed. Discovery at the same time of a pancreatic well-differentiate endocrine tumor and a stomach stromal tumor.

-July2012:Local and regional recurrence(lung, pleura, liver).

Case 3: Female patient born in 1944 carrying a MEN1 mutation.

-1990: Primary hyperparathyroidism initially treated by a resection of the two lower parathyroid in 1990 then by a complete parathyroidectomy(Hyperplasia)followed by a parathyroid gland reimplantation on the left arm in 1994.

-2004:Distal spleno-pancreatectomy(Well-differentiated pancreatic neuroendocrine tumor) and left adrenalectomy(Hyperplasia).

-2010:Discovery of lower-grade astrocytoma. Unremarkable pituitary MRI.

-2012:Quick appearance in 3 weeks of a tumor on the rooth of the left thigh.

The biopsy showed an undifferentiated pleomorphic liposarcoma stage II.

Conclusion: These 3 cases from the French MEN-1 Register(1570 cases) show that liposarcoma is not rare within MEN1 population compared to the general population (1/100000 person/year). Thus the association of the two entities may not be fortuitous. Further research is warranted and more cases are needed to establish that liposarcoma might be a new tumor type in patients with MEN1.