Es Cushing Localize Resect Ectopic Acth Tumors

Localizing and Resecting Ectopic ACTH-Secreting Tumors with Node Dissection

STEP 1 — Gather Information

Confirm biochemical hypercortisolism (elevated UFC or late-night salivary cortisol) and elevated ACTH; obtain pituitary MRI to exclude adenoma; perform inferior petrosal sinus sampling (IPSS) to assess central vs peripheral ACTH source; if peripheral, pursue anatomic imaging (contrast-enhanced CT chest/abdomen/pelvis, somatostatin receptor PET/CT, or Ga-68 DOTATATE) to localize tumor; document size, location, and presence of metastatic nodes.

STEP 2 — Rule In / Rule Out

Is ectopic ACTH secretion confirmed by peripheral IPSS gradient and/or identification of a tumor on imaging? If yes, proceed to localization and resection planning; if no, reconsider Cushing’s disease or adrenal etiology and repeat biochemical testing or pursue alternative diagnostic pathways.

STEP 3 — Classify or Stratify

Classify the ectopic ACTH source as occult (no lesion on conventional CT/MRI but positive functional imaging) versus metastatic (radiographically evident lymph node or distant metastases); this determines extent of surgical dissection needed.

STEP 4 — Decide

For localized occult or resectable metastatic ectopic ACTH tumors, recommend en bloc surgical resection with systematic mediastinal or abdominal lymph node dissection; for unresectable widespread metastasis, consider medical therapy (ketoconazole/metyrapone) or bilateral adrenalectomy as a life-preserving measure while awaiting systemic treatment.

Clinical Guardrails / Mimics / Pitfalls

Do not rely solely on pituitary MRI; false-negative IPSS can misdirect to pituitary surgery; avoid resection without histologic confirmation when possible; neglecting node dissection increases recurrence risk; proceed to surgery only after multidisciplinary review (endocrinology, thoracic surgery, nuclear medicine); avoid empiric medical therapy without localization in operable disease.

Concrete Clinical Example

A 48‑year‑old with refractory hypertension, hyperglycemia, and hypokalemia had UFC 3× ULN and ACTH 120 pg/mL; pituitary MRI was negative; IPSS showed peripheral gradient; CT chest revealed a 1.5 cm bronchial carcinoid; video‑assisted thoracoscopic resection with mediastinal lymph node dissection yielded normal postoperative UFC and ACTH; patient remained eucortisolemic at 6‑month follow‑up.

Source: Treatment of Cushing’s Syndrome: An Endocrine Society Clinical Practice Guideline, Nieman et al., 2015, DOI:10.1210/jc.2015-1818