Tuberculosis of the thymus in a 6-month-old infant with literature review

Thymoma and Tuberculoma: Unexpected Coexistence

Mediastinal tumours can be incidental findings on chest x-ray or present with systemic symptoms and/or direct effect of the mediastinal mass. We report the case of a woman with symptomatic thymoma B1 and simultaneous thymus tuberculosis.

LEARNING POINTS

The association of tuberculosis (TB) of the thymus and thymoma is extremely rare.The differential diagnosis of a mediastinal mass should include TB, particularly in endemic regions.Mediastinal mass resection or biopsy can be of great value in diagnostic work-up.

Tuberculosis, the Disrupted Immune-Endocrine Response and the Potential Thymic Repercussion As a Contributing Factor to Disease Physiopathology

Upon the pathogen encounter, the host seeks to ensure an adequate inflammatory reaction to combat infection but at the same time tries to prevent collateral damage, through several regulatory mechanisms, like an endocrine response involving the production of adrenal steroid hormones. Our studies show that active tuberculosis (TB) patients present an immune-endocrine imbalance characterized by an impaired cellular immunity together with increased plasma levels of cortisol, pro-inflammatory cytokines, and decreased amounts of dehydroepiandrosterone. Studies in patients undergoing specific treatment revealed that cortisol levels remained increased even after several months of initiating therapy. In addition to the well-known metabolic and immunological effects, glucocorticoids are involved in thymic cortical depletion with immature thymocytes being quite sensitive to such an effect. The thymus is a central lymphoid organ supporting thymocyte T-cell development, i.e., lineage commitment, selection events and thymic emigration. While thymic TB is an infrequent manifestation of the disease, several pieces of experimental and clinical evidence point out that the thymus can be infected by mycobacteria. Beyond this, the thymic microenvironment during TB may be also altered because of the immune-hormonal alterations. The thymus may be then an additional target of organ involvement further contributing to a deficient control of infection and disease immunopathology.

Clinicopathological Characteristics of Thymic Tuberculosis- A Rare Entity

Tuberculosis is a severely debilitating disease and it rarely presents with involvement of the thymus. Only fifteen cases have been reported worldwide. We report a case of thymic tuberculosis in a 12-year-old female presenting with cervical lymphadenopathy. Computed tomographic imaging revealed a mediastinal mass which was then excised via thoracotomy. The gross appearance of the cut surface of both lobes was variegated with white, granular caseating material. Microscopy revealed multiple, caseating, epithelioid granulomas with dispersed Langhans giant cells surrounded by thymic parenchyma with Hassals corpuscles. The patient was treated with anti-tubercular drugs and her condition improved. On follow up, the patient is healthy and has gained weight.