A rare case of medullary carcinoma

Abstract

Medullary thyroid cancer (MTC) accounts for 5–10 % of all thyroid cancers. Most cases (75 %) are sporadic, but the proportion of patients with MTC and a familial predisposition syndrome is the highest among those with any hereditary cancer syndrome (about 25 %), and this possibility should be considered when examining a patient with MTC. Familial syndromes include multiple endocrine neoplasia (MEN) 2A, MEN 2B, and non-MEN familial MTC (familial MTC). Familial MTC syndromes occur in approximately one case per 30,000 of the population. Reduced penetrance and clinical variability are well-established features of many monogenic disorders, particularly phenotypes associated with the RET proto-oncogene. They require an individual assessment of the pathogenic effects and clinical significance of any identified new sequence of the RET va­riant as prerequisites for individual genetic counseling and planning of medical monitoring and treatment. Diagnostic criteria for the disease have been outlined, molecular and genetic aspects have been discussed, and the determination of treatment and further observation has been addressed. The article describes a clinical case of a rare variant of MTC. Treatment of this pathology with radical extrafascial thyroidectomy is under consideration. Given the ineffectiveness of radioiodine and chemotherapy, the main task in the treatment of MTC is early diagnosis, radical surgical intervention, and active monitoring aimed at early detection of disease recurrence. When planning prophylactic thyroidectomy, it is recommended to focus on the stratification of the level of RET gene mutations and the timing of prophylactic thyroidectomy proposed by the American Thyroid Association. The introduction of molecular genetic research into clinical practice for the purpose of diagnosing MTC allows for the objective assessment of the genetic lineage of the disease within a biological family. A timely diagnosis of MTC makes it possible to prescribe an adequate treatment at the stage of preclinical manifestations of the disease, which can significantly increase the quality and duration of life.