Neuroendocrine Tumors: Clinical, Histological and Immunohistochemical Perspectives and Case Report-Mature Teratoma in a 16-Year-Old Girl.

A mature teratoma is a germinal neoplasm that differentiates from embryonic multipotent cells into three germ layers. There may also be glandular tissue. The literature describes a total of 658 cases of ovarian neuroendocrine neoplasms, mainly in women over 40 years of age. The authors, together with a systemic review, present a case of a 16-year-old girl diagnosed with and treated for a neuroendocrine tumor. Case description: A 16-year-old girl visited the Paediatric Gynaecology Outpatient Clinic because of abdominal pains that intensified during menstruation. Standard painkillers and diastolic drugs were ineffective. An ultrasound examination revealed a large tumor with a heterogeneous structure in her right ovary. A sparing operation was carried out. During laparotomy, the lesion was enucleated, leaving healthy tissue. Histopathological examination revealed the typical features of teratoma, as well as the coexistence of a G1 neuroendocrine tumor. Immunohistochemical examination (IHC) showed the presence of markers characteristic for this type of tumor. The patient requires constant monitoring in the Endocrinology and Oncological Gynaecology Clinic. Conclusion: Tissue of neuroendocrine neoplasm within a teratoma is rare in this age group of patients; thus, there are currently no standards for long-term follow-up. This case adds to the body of evidence and demonstrates a possible good prognosis with non-aggressive behavior in G1 neuroendocrine tumors and teratomas in young patients.