Abstract PO5-20-11: Synchronous Breast Cancer and Pheochromocytoma: A Case Series
Authors: Dahake Nikita , Tushir Abhimanyu , Padmanabhan Aruna 
Published: May 2024

Abstract
Background:
Pheochromocytomas are rare, although literature suggests a rising incidence due to the widespread use of sensitive imaging modalities. Synchronous presentation of breast cancer with a pheochromocytoma is exceedingly rare with only one case documented in the literature. We present two cases of malignancy in the breast in which pheochromocytomas were incidentally detected during workup and management with vastly different presentations.
Case Presentation:
Two patients presented with breast cancer and were secondarily diagnosed with pheochromocytoma.
Patient 1 is a 48-year-old postmenopausal female with a history of intraductal papilloma four years prior, who presented with right breast nipple discharge. Diagnostic mammogram showed a right breast mass and biopsy confirmed an intraductal papilloma with intermediate-grade DCIS, ER+/PR-. She had no family history of cancer or PGL/PPC. During a scheduled lumpectomy, she developed hypoxia, hypotension, and flash pulmonary edema requiring intubation and ECMO with prolonged ICU stay and long recovery with tracheostomy for four months. Contrast-enhanced CT of her abdomen showed a 9 cm right adrenal mass. Serum and urine metanephrines were markedly elevated, and it was determined that she had an adrenal crisis secondary to undiagnosed pheochromocytoma. She completed treatment for DCIS with lumpectomy and radiation and is currently on adjuvant anastrozole. She additionally had an adrenalectomy for pheochromocytoma, which was found to be stage PASS 2. Subsequent genetic testing confirmed the absence of germline mutations associated with hereditary PGL/PPC or breast cancer.
Patient 2 is a 57-year-old female presenting with a history of left breast mass she first noted a year ago, with newly found nipple retraction and skin changes. Biopsy showed invasive ductal carcinoma of the breast, G3, Stage IIIA, pT3N2aM0, ER 95%/PR-/Her2- (IHC 0). Staging PET scan showed a 3.4 cm hypermetabolic left adrenal mass in addition to the breast mass and left axillary adenopathy. Serum and urine metanephrines were elevated, and pheochromocytoma was diagnosed. Family history was positive only for pancreatic cancer in a maternal aunt. Comprehensive genotype testing was negative for hereditary breast cancer and PGL/PCC syndromes. She was concomitantly treated with a radical mastectomy for breast cancer and a left adrenalectomy and tolerated the procedure well as she received perioperative alpha-adrenergic blockade with doxazosin. She has received chemotherapy and radiation for breast cancer treatment and is currently on adjuvant anastrozole. The adrenal mass was confirmed to be a pheochromocytoma PASS 2-3.
Discussion:
We present two unique cases of breast cancer and pheochromocytomas discovered in tandem with variable clinical manifestations. It is extremely uncommon to have a presentation of primary breast malignancy concomitantly with pheochromocytoma, and we demonstrate two cases that occurred within months of one another at our facility.
During the first case, metastatic workup was not indicated for DCIS. However, during the seemingly benign lumpectomy procedure, the patient experienced significant complications, leading to intense ICU management, intubation, and tracheostomy. In the second case, a metastatic workup was completed due to locally advanced breast cancer where the adrenal mass was detected and a pheochromocytoma was diagnosed prior to surgery. This allowed both cancers to be resected simultaneously and safely. This series demonstrates the importance of keeping pheochromocytomas in the differential during the workup of adrenal masses prior to surgical interventions. Additionally, they demonstrate how the usual workup and management of breast cancer does not take into account these rare but significant diagnoses, and that can result in fatal consequences.
Citation Format: Nikita Dahake, Abhimanyu Tushir, Aruna Padmanabhan. Synchronous Breast Cancer and Pheochromocytoma: A Case Series [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-20-11.