Anterior mediastinal mass in children following chemotherapy for malignant disease: thymic hyperplasia vs recurrence

[Thymic hyperplasia: A study of 46 cases]

BACKGROUND

Thymic hyperplasia presents as an anterior mediastinal mass and poses important diagnostic and therapeutic challenge. Two types of thymic hyperplasia are described: true hyperplasia and follicular hyperplasie. Literature data are peculiar concerning both entities. We aimed to describe the clinical and microscopic characteristics of thymic hyperplasia through a single institution experience during an 11-year-period.

METHODS

Thymic hyperplasia diagnosed during the period between 2009 and 2020 were included.

RESULTS

In all, 46 thymic hyperplasias were diagnosed. The 46 patients consisted in 33 women and 13 men with a mean age of 30 years. Microscopic diagnosis concluded to a follicular hyperplasia in 12 cases and a true thymic hyperplasia in 34 cases. The diagnosis of true thymic hyperplasia posed a diagnostic challenge with an involuted thymus in 1 case and a thymolipoma in 1 case. The confrontation with the clinical data allowed retaining the diagnosis.

CONCLUSION

The diagnosis of thymic hyperplasia is based on microscopic features. The confrontation with clinical data and the measurements of the thymus according to the age allow to retain the diagnosis in most challenging cases.

A Developing Anterior Mediastinal Mass In A Breast Cancer Patient : Thymic Hyperplasia

INTRODUCTION

True thymic hyperplasia following chemotherapy have been described mostly in children.There are a few cases of thymus hyperplasia have been reported in breast cancer patients . Diagnosis of this unusual entity is very crucial to pretend unnecessary surgery or interventional diagnostic procedures.

CASE PRESENTATION

We report a case of thymus hyperplasia in a patient who was operated and treated with adjuvant chemotherapy for stage 2 breast cancer two years ago. In the follow-up CT scans an anterior mediastinal mass was noted. Radiologic evaluation and follow up revealed thymus enlargement.

DISCUSSION

Thymic hyperplasia following chemotherapy have been described in both children and adults, but occurs mostly in children and adolescents treated for lymphoma and several other types of tumors. Few cases are reported in literature describing thymus hyperplasia following chemotherapy in a breast cancer patient.

CONCLUSION

Radiologists must be aware of this unusual finding in breast cancer patients treated with chemotherapy to guide the clinicians appropriately in order to avoid unnecessary surgical intervention, additional invasive diagnostic procedures, or chemotherapy.