An Overlooked Tumor of the Lung in Cushing's Syndrome: Adrenocorticotropic Hormone-Secreting Carcinoid Tumor

Introduction

Adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome may result from ectopic ACTH secretion in 15 - 20 % of patients [[1]]. Several diagnostic procedures including an endocrine workup and inferior petrosal sinus sampling to exclude a pituitary tumor are usually carried out to establish the origin of ectopic ACTH, however, the source of ectopic ACTH is not easily ascertained [[2]]. Moreover, many cases, ranging from 30 - 42 %, unnecessarily undergo either a hypophysectomy or an adrenalectomy [[3], [4], [5]].

We report here a case with Cushing's syndrome resulting from a pulmonary carcinoid tumor diagnosed 13 months following the onset of symptoms. Histological diagnosis revealed a typical carcinoid tumor with mediastinal lymph node involvement. We wish to emphasize this exceptional location of this carcinoid tumor, which may be overlooked unless suspected, and also the necessity of mediastinal lymph node dissection regardless of the nature of the tumor.

References

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