Abstract
There is scarcely any organ or tissue which has not been reported to have been involved in sarcoidosis, with the exception of the adrenals. Although the thymus is closely related to the lymphoid tissue, which is most liable to sarcoidosis lesions, there has been no report on its involvement to date. As sarcoidosis is usually found among adults or older children and rare among younger ones, there is the possibility that involvement of the remaining thymus tissue might have been overlooked. We have observed two sarcoidosis cases, aged 15 and 13, with mediastinal shadows indicating an enlarged thymus on chest radiographs with pneumomediastinum.
Case 1. A boy, aged 15, developed uveitis with granuloma in the iris of the left eye. He had generalized enlargement of lymph-nodes, affecting the occipital, retroauricular, cervical, axillary, cubital, inguinal, femoral and popliteal nodes. Biopsy of a femoral lymph-node showed epithelioid cell tubercles with scanty necrosis (Fig. 4). The tuberculin reaction, positive before 6 months, was negative to 5 TU. A chest radiograph showed bilateral hilar lymph-node enlargement (BHL), with faint mottling in both lungs. The mediastinal shadow was markedly enlarged with bilateral straight borders (Fig. 1). On tomographs this shadow was bestdefined just behind the sternum (Fig. 3, 5). A lateral radiograph showed a tumorous mass in the upper portion of the anteior mediastinum, suggestive of an enlarged thymus (Fig. 2). Prednisolone, to a total dose of 850mg, was administered for 52 days. The broad mediastinal shadow and BHL regressed rapidly and subsided almost completely after 1 month (Fig. 6), and no relapse was observed after corticosteroids were discontinued. The enlarged superficial lymph-nodes were reduced in size during the corticosteroid treatment, but enlarged again after the withdrawal. The uveitis deteriorated in spite of the repeated administration of corticosteroid, and the left eye lost its vision due to cataract formation after 11/2 years.
Case 2. A girl, aged 13, was found to have BHL on a routine chest radiograph. The right inguinal lymphnodes were enlarged. Biopsy of one of them showed noncaseating epithelioid cell tubercles with giant cells (Fig. 9). A tuberculin reaction, previously positive for 7 years, was negative to 5 TU. Chest radiographs showed enlargement of the mediastinal shadow with BHL (Fig. 7), and a tumorous mass in the upper portion of the anterior mediastinum in lateral view (Fig. 8). Tomographs with pneumomediastinum demonstrated this mass more clearly, suggesting enlargement of the thymus (Fig. 10, 11). Prednisolone, to a total dose of 1, 225mg, was administered for 75 days. The tumorous mediastinal shadow and BHL regressed rapidly and subsided almost completely within 3 months. Inguinal lymph-nodes were also markedly reduced in size. Pneumomediastinum showed no tumorous mass in the anterior mediastinum 21/2 months after discontinuance of the corticosteroid (Fig. 13, 14). At that time the tuberculin reaction converted to positive. The Kveim reaction with the antigen prepared from patient's own inguinal lymph-node was negative after corticosteroid treatment.
Two cases of sarcoidosis with tumorous mediastinal shadows indicative of an enlarged thymus are presented. Both had enlarged superficial lymph-nodes besides BHL. These mediastinal shadows regressed rapidly on the administration of corticosteroid. Whether this means thymus sarcoidosis or not, remains to be proven by biopsy on other patients.
