CUTANEOUS TUMOUR IN MULTIPLE ENDOCRINE NEOPLASIA TYPE 1

Abstract

INTRODUCTION/BACKGROUND

Multiple Endocrine Neoplasia (MEN) 1 syndrome is a genetic disease characterized by pituitary adenoma, para- thyroid hyperplasia, and pancreatic tumors. Cutaneous manifestations of the syndrome are rare. We report a case of MEN 1 syndrome with collagenoma, initially misdiagnosed as neurofibromatosis.

CASE

A 48-year-old male with hypertension and gouty arthritis was diagnosed with Neurofibromatosis type 1 10 years ago based on neurofibromas on his neck and abdomen. He defaulted follow-up until admission in June 2024 for hypertensive emergency. During admission, incidental findings of asymptomatic moderate PTH-dependent hyper- calcemia (corrected calcium: 3.02 mmol/L, phosphate: 0.37 mmol/L, iPTH: 31.9 pmol/L [Normal range 1.58 - 6.03]) and a suspicious right hilar mass on chest X-ray, prompting further workup. Calcium-creatinine clearance ratio was

0.046. His tumor marker levels, including B-HCG, were normal. CT of the thorax, abdomen, and pelvis showed a solid anterior mediastinal mass with a superior mediastinal lesion and an enhancing pancreatic mass. A DOTATATE scan confirmed somatostatin receptor avid disease in the pancreas and anterior mediastinal mass with nodal, liver, and bone metastases. CT-guided biopsy of anterior mediastinal mass followed by anterior mediastinal mass resection and endoscopic guided biopsy of pancreatic mass confirmed neuroendocrine tumor. His clinical condition

was suggestive of MEN 1. It is exceptionally rare for two autosomal dominant syndromes to coexist. There was no other diagnostic manifestation for neurofibromatosis type 1 except for skin lesions. Skin biopsy was done and reported as collagenoma, supporting MEN 1. Genetic study is ideal but limited by financial constraints.

CONCLUSION

Without the luxury of genetic testing, tactful correlations of clinical manifestations are essential to diagnose rare inherit- able syndromes. Relevant investigations may help identify clinical signs and their association with the syndrome. In our patient, the initial diagnosis of neurofibromatosis was later revised to collagenoma with MEN 1 after HPE result from skin biopsy.