T-lymphoblastic lymphoma of mediastinal lymph nodes with secondary thyroid involvement in an adolescent
Authors: Pasternak I. A. , Kazachkov E. L. , Pasternak A. E. 
Published: May 2023

Introduction Among tumors of lymphatic tissue, T-lymphoblastic lymphoma is a rare disease, with children and adolescents being affected more often. The thymus, lymph nodes and various extranodal localizations are involved in the tumor process, but no descriptions of secondary thyroid involvement in the tumor process in children with primary lymphoma of other localizations were found in the available literature.

The aim of the study was to describe a rare observation of secondary thyroid involvement in mediastinal lymphoma with deciphering of tumor immunophenotype in an adolescent immunomorphological analysis of surgical material.

Materials and methods. We analyzed the archived medical records, data of clinical, laboratory, instrumental and morphological studies of non-Hodgkin’s lymphoma of mediastinal lymph nodes with thyroid involvement. Histological examination of the material stained with hematoxylin and eosin followed by immunohistochemical examination with a set of 16 mono- and polyclonal antibodies was carried out 22 years later on the archive paraffin blocks.

Results Morphological examination of the thyroid biopsy specimen and resectate of its isthmus made pathological and anatomical conclusion: non-Hodgkin’s lymphoma of the thyroid gland, prolymphocytic variant. Thanks to an adequately planned program of polychemotherapy, it was possible to achieve long-term remission with a 22-year recurrence-free survival rate. The retrospective data of clinical, instrumental, laboratory investigations and the results of immunohistochemical analysis of the archived tissue material with the help of a panel of 16 mono- and polyclonal antibodies were compared and the following conclusion was made: C83.5 (ICD-O code 9837/3) upper mediastinal lymphocytic T-lymphoma with secondary damage of the thyroid gland. Complete remission after polychemotherapy with a 22-year recurrence-free survival.

Discussion It was shown that correctly planned treatment on the basis of competent identification of the histo- and cytogenesis of the tumor in the course of well-coordinated teamwork of specialists of different profile (hematologists, pathologists, chemotherapists, etc.) resulted in a favorable outcome. We managed to achieve a long-term remission with no recurrence of the disease for 22 years. By means of immunomorphological analysis, based on the recommendations of new classification of the haemopoietic and lymphoid tissue tumors, at the present stage of medical science development we managed to decode the tumor immunophenotype, which made more concrete, but not refuted the pathological anatomists’ conclusion, made 22 years ago.

Conclusion Analysis of the presented case showed that the tumor immunophenotype corresponded to T-lymphoblastic lymphoma with secondary thyroid involvement. In spite of the fact that in this tumor any extranodal localization is possible, in the available literature we could not find any information about secondary involvement of thyroid in tumor process.