Multiple endocrine neoplasia and primary hyperparathyroidism – practical approach

The main issue Neuroendocrine tumours can be associated with genetic syndromes [1] and this fact should influence the medical procedures. In my work as a physician I met several patients with cancer in familiar history (e.g. colon cancer in the mother and grandmother) and despite the recommendations they avoid screening for the disease. In this year I was dealing with an adult male patient suffering because of a neuroendocrine tumour affecting duodenum with metastases to the liver. In 2013 due to the diagnosis of low-energy fractures, the hyperparathyroidism had been diagnosed in this man. The patient on account of the well-being neglected treatment and doctor visits. Since the origin of 2015 year he began to feel worse. He felt weakness and complained a loss of body weight despite the steady food supply. Above introduction concerning the patient from my practice prompted me to reflect on the relationship of individual components of familial syndromes associated with neuroendocrine tumours. Although the primary hyper-parathyroidism usually originates from benign adenoma without any relationship to syndromes associated with endocrine tumours, in some cases it can develop from the existing multiple endocrine neoplasia type 1 and 2a (MEN 1 and MEN 2a respectively) as well as be the result of hereditary hyperparathyroidism jaw tumour syndrome [1, 2]. There are also authors (e.g. Thakker, 2014) using names MEN2 for MEN2A, MEN3 for MEN2B and distinguish the type MEN4 for some form classified until recently to MEN1, but with a different genetic mutation. Abnormalities of CD-KN1B gene which in man is located on chromosome 12p13 are considered to be the cause of MEN4. Parathyroid ad-enoma, pituitary adenoma, reproduction organ tumours (e.g. testicular cancer, neuroendocrine cervical carcinoma), adrenal and renal tumours are classified as components of MEN4 syndrome [3]. There are no reports of any others familiar syndromes associated with neuroendocrine tumours and primary hyperparathyroidism. From written previously syndromes causing primary hyperparathyroid-ism MEN1 is the most frequent and the best known. Primary hyperparathyroidism is usually the first in medical history and the most common endocrynopathies in MEN1 [2]. Although incidence of MEN1 in patients diagnosed with primary hyperparathyroidism is estimated in range of 2–4%, the hyperparathyroidism reaches nearly 100% penetrance by the age of 50 years in MEN1 patients [2]. The others syndromes associated with neuroendocrine tumours carry even lower probability of primary hyper-parathyroidism e.g. in MEN2/MEN2a it is rarer. It occurs in 20–30% of patients, is also later …