Postpartum Pheochromocytoma and Ectopic ACTH Secretion: The First Report of a Case in Which Both Mother and Child Survived

Presentation Number: SUN-0791
Date of Presentation: June 22nd, 2014

Christian Perez*1, Mark Ott2 and Joel R L Ehrenkranz2
1University of Utah School of Medicine, Salt Lake City, UT, 2Intermountain Healthcare, Murray, UT

Abstract

Background: There are 25 reported cases of ectopic ACTH secretion associated with pheochromocytoma. Two of these cases occurred in the postpartum period and resulted in either fetal or maternal death (1,2).

Clinical Case:  A 27 year-old woman had a four-year history of paroxysmal hypertension.  Workup of her postpartum labile hypertension showed elevated plasma normetanepherine (19.3 nmol/L; nl <.89 ) and 24 hr urinary metanepherines and normetanepherines (2911 µ/dl and 40826 µgm/dl respectively; nl <350 and <650).  MRI showed a large adrenal mass.  Over an eight week period following delivery, the patient developed hypokalemia, edema, altered mental status, hyperglycemia, and right upper lobe pneumonia due to Moraxella Catarrhalis.  120 mEq KCl supplementation per day was needed to maintain her serum K >3.2 mmol/L.  24 hour urinary cortisol was 275 µgm/dl (nl <45).  ACTH rose from 316 pg/ml to 605 pg/ml (nl <58 pg/ml) over a 3-day period.  Imaging of the pituitary, chest, and pelvis was normal.  CT of the abdomen showed a hypodense intrahepatic lesion interpreted as metastatic pheochromocytoma.

The patient’s pneumonia responded to ceftriaxone; blood pressure was controlled with alpha and beta blockade; hypercortisolism was treated with mifepristrone and spironolactone.  The patient underwent a right adrenalectomy and liver biopsy of the lesion identified on CT.  Intraoperative pathology of the adrenal tumor was consistent with a pheochromocytoma; biopsy of the liver CT lesion showed no malignant cells.  There was no evidence of retroperitoneal or abdominal metastases.  Examination of stained tissue confirmed the intraoperative diagnoses.  Immunohistochemical staining for ACTH identified ~10% ACTH stain positive cells distributed throughout the adrenal tumor.  Genetic markers of RET mutations were not present.

The patient’s hypertension, hypokalemia, and altered mental status remitted in the immediate postoperative period.  8 am ACTH and cortisol levels on postoperative day 1, while the patient was receiving dexamethasone 2 mg iv q6h, were <5 pg/ml (nl>6) and 2.8 µgm/dl (nl> 6) respectively.  The patient was discharged home on the second postoperative day feeling “the best I’ve felt in four years”.  

Conclusion:   This is the first case report of a pheochromocytoma present prior to and throughout pregnancy with the new onset of Cushing's syndrome following delivery in which both the fetus and mother survived.   Although the patient had symptoms consistent with a pheochromocytoma for four years, hypercortisolism appeared following delivery and had a very aggressive course resulting in opportunistic infection, encephalopathy, and life-threatening hypokalemia.  Immunohistochemistry suggested a non-clonal original of ACTH secreting cells in the adrenal tumor.  The basis for the new onset of ectopic ACTH secretion from a pheochromocytoma in the postpartum period remains to be determined.

 

Nothing to Disclose: CP, MO, JRLE