Endocrine Abstracts

Introduction: Thymic hyperplasia has been described after hypercortisolism resolution. The natural history remains poorly defined: emergence ≧1 month after hypercortisolism resolution, variable duration, usually spontaneous resolution/benign course.

Case Report: ♂, 24, referred in 2000 for secondary hypothyroidism: TSH: 0.25 μUI/ml (0.25–5); FT4: 5.55 pmol/l (9–20). Clinical evaluation: insomnia, nocturnal sweating, facial erythema, myalgias, asthenia; acne, abdominal purple striae; BMI: 24.1 kg/m². Total testosterone-1.8 ng/ml (2.7–11), ACTH-104 pg/ml (9–52), UFC-495 μg/24 h (10–80); Cortisol-17 μg/dl (5–25).

CRH test: ACTH-51, 48, 52 pg/ml (baseline, 15, 30 min respectively); cortisol-110, 188, 211, 176 μg/dl (baseline, 15, 30, 45 min respectively).

Pituitary MRI (07/2000): ‘dimensions slightly greater than expected, stalk without deviation; no hypothalamic alterations’. He starts ketoconazole 400 mg/day; dose adjustments (UFC/clinical). Cervico-thoraco-abdominal CT (08/2000):normal. Octreotide scintigraphy (10/2000): ‘Focus uptake in the right hemithorax.’ Bronchoscopy (01/2001): Normal. In Jan/2001 worsening of hypertension and hypokalemia: KCl+spironolactone were started; at that time UFC 60 μg/24 h, ACTH 159 pg/ml, cortisol 13 μg/dl. Lung surgery (04/2001): ‘2 lymph nodes without neoplastic aspects removed.’ Inferior petrosal sinuses catheterization (05/2001): no gradient. Octreotide scintigraphy (07/2001): ‘more evident fixation’. Thoraco-abdominal CT(07/2001): ‘Nodular image in the area corresponding to scintigraphy.’ Lung surgery(octreotide-labeled probe; 08/2001):‘Bronchial carcinoid.’ Steroid substitution was done during 9 months, with progressive hypercortisolism stigmata regression. Chest CT (2002): ‘anterior mediastinum retrosternal triangular formation; thymus? conglomerate adenopathy?’. Chest CT (2003; 2006): ‘mass probably related to thymus…31×16 mm’. Chest CT (2011): ‘normal appearing mediastinum, centered, no adenopathy’. The patient maintains follow-up.

Conclusions: This case illustrates the frequent difficulty in localizing the source of ACTH production, and the possible association of a thymic hyperplasia occurring after the hypercortisolism resolution. A self-limiting evolution is to consider.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.