P-42 A delayed diagnosis of MEN1 syndrome
Authors: Karslı Seda , Mert Meral , Çiftçi Sema , Pişkinpaşa Hamide , Bozkır Evin , Sipahi Murat , Çakır Ilkay 
Published: January 2024

Abstract

Introduction
Multiple endocrine neoplasia 1 (MEN 1) is a rare autosomal dominantly inherited syndrome that results from mutations in the MEN1 gene. It is characterized by multiple tumors of endocrine glands and some other tissues. Early diagnosis is crucial for optimal management. Here we present a patient with delayed diagnosis and preventable metastatic disease.

Clinical Case
A 46-year-old male patient who was referred from gastroenterology clinic to our outpatient clinic following distal pancreatectomy. The postoperative pathology was reported as a well-differentiated neuroendocrine tumor (NET) with 3 focuses (60 mm, 9 mm and 2.5 mm in size). Six months ago, he underwent to Magnetic Resonance Imagination (MRI) of the abdomen because of abdominal pain and 17 kg weight loss in a year, that revealed a 69×67 mm cystic lesion in the tail of the pancreas (Figure 1A). Laboratory and physical examinations were in accordance with a nonfunctioning lesion (Table 1).
The findings of the Gallium-68 DOTATATE PET/CT suggested residual and metastatic disease during follow-up (At the level of the pancreatic corpus, increased uptake was detected in two lesion sites adjacent to liver segment 3 and in various nodular lesion areas, the largest of which was approximately 20 mm in diameter, adjacent to the duodenum and pancreas (Figure 1B and 1D). No increased uptake was observed in the pancreas and these lesions in preoperative FDG/PET (Figure is not shown). The patient was consultated by oncology clinic and 177-Lutetium-DOTATATE and octreotide treatments were started.
Parathyroidectomy and total thyroidectomy 7 years ago was noted in the patient's medical history. Persisting hypercalcemia and elevated PTH were also remarkable in laboratory testing (Table 2). The patient didn't apply to endocrinology clinic after parathyroidectomy and hypercalcemia had been overlooked for 7 years. Further investigation revealed a nonfunctioning 4 mm diameter pituitary lesion (Figure 1C). So the diagnosis of multiple endocrine neoplasia type 1 was suspected. Genetic test detected a c.784-2A&gt;G spice site variant in MEN1 gene in heterozygous form.
The patient denied a family history for MEN 1 but he reported that his father died at the age of 40 and his uncle at the age of 39 due to an illness of unknown origin, and two sons of the same uncle were followed up for parathyroid disease. Family screening and genetic counseling were recommended. Surgery of the remaining parathyroid glands and implantation in the forearm and thymectomy were planned.

Conclusion
MEN syndromes are rare and hypercalcemia is generally the initial presentation. Persistence of hypercalcemia following parathyroidectomy should be warning, and the possibility of MEN -1 syndrome should also be kept in mind even in the lack of family history. As in the presented case, diagnosis may be delayed due to late appearance of symptoms of other components, especially nonfunctional pancreaticoduodenal tumors.Figure 1.MRI and Ga-68 PET/CT images of the patientA: A 69×67 mm cystic lesion in the tail of the pancreas B: Increased Gallium-68 DOTATATE uptake at the level of the pancreatic corpus adjacent to liver segment 3 (SUVmax: 67.90) C: A nonfunctioning 4 mm diameter lesion in the right half of the pituitary D: Increased uptake of Gallium-68 DOTATATE in nodular lesions adjacent to the duodenum and pancreas (SUVmax: 31.09) Table 1.Laboratory results of the patientACTH: Adrenocorticotropic hormone, FSH: follicle stimulating hormone, LH: luteinizing hormone, IGF-1: Insülin-like growth factor, TSH: Thyroid stimulating hormone, 1 mg DST: dexamethasone suppression test Table 2.Calcium and PTH levels of the patient before parathyroidectomy and following parathyroidectomy*Before parathyroidectomy ** Following parathyroidectomy PTH: Parathyroid hormone