FINDING THE CULPRIT: A RARE CASE OF METASTATIC ADRENOCORTICAL CARCINOMA TO THE LUNG WITH CONCURRENT PRIMARY NEUROENDOCRINE TUMOR OF THE LUNG

Abstract

TOPIC: Lung Cancer TYPE: Medical Student/Resident Case Reports INTRODUCTION: Adrenocortical carcinoma (ACC) is a rare malignancy with an incidence of 1 - 2 million cases per year. Most ACCs are sporadic and nonfunctioning which leads to incidental discovery. However, they are frequently aggressive tumors that are systemically advanced at the time of diagnosis. CASE PRESENTATION: A 66-year-old male smoker with coronary artery disease, hypertension, and mitral regurgitation was admitted for one month of progressively worsening dyspnea and bilateral lower extremity edema. Initial labs revealed BNP of 1,136 pg/ml with normal EKG. However, chest x-ray showed countless nodules throughout the bilateral lungs. CT revealed a 15 cm adrenal mass and innumerable pulmonary nodules suggesting metastatic disease. After 24-hour urine metanephrine resulted in normal range, a core biopsy of the adrenal gland showed focal areas of clear cells with abnormal mitoses and necrosis while staining positive for Melan A, inhibin, and calretinin. These findings were consistent with ACC. After outside records were obtained, patient was noted to have recent lung biopsy that was morphologically and immunohistochemically unique, instead showing uniform cells with synaptophysin and chromogranin positivity. A 68-Gallium Dotatate PET/CT then confirmed an intensely tracer-avid 2.5 cm right middle lobe tumor most consistent with a primary neuroendocrine tumor (NET) of the lung. On the other hand, the remaining lung nodules and adrenal mass demonstrated low-level uptake and consequently were determined to be from primary ACC. The patient was started on etoposide, doxorubicin, and cisplatin with mitotane (EDP-M) for metastatic ACC treatment. DISCUSSION: This case demonstrates a unique case of two primary cancers with extensive pulmonary metastases secondary to ACC. NETs produce increased neurosecretory granules reflected in expression of markers such as chromogranin A and synaptophysin, while ACC expresses Melan A, inhibin, and calretinin. Malignant ACC can further be classified using the Weiss criteria: >6 mitoses per 50 high-power fields, <25% clear tumor cells, abnormal mitoses, necrosis, and capsular invasion. In addition, 68-Gallium Dotatate PET/CT can detect the somatostatin receptors found in NETs. The standard of care is recommended based on the FIRM-ACT trial that showed superiority of the 4-drug regimen EDP-M. CONCLUSIONS: In this unusual case of primary NET of the lung and primary ACC, the 68-Gallidium Dotatate PET/CT can determine the type of tumor that metastasized to the lung. Metastatic ACC is very challenging to treat and currently, EDP-M offers the best chance of extending survival. REFERENCE #1: Fassnacht, M. et al. European Society of Endocrinology Clinical Practice Guidelines on the management of adrenocortical carcinoma in adults, in collaboration with the European Network for the Study of Adrenal Tumors. Eur J Endocrinol 179, G1–G46 (2018). REFERENCE #2: Else, T. et al. Adrenocortical carcinoma. Endocr Rev 35, 282–326 (2014). REFERENCE #3: Kerkhofs, T. M. A. et al. Adrenocortical carcinoma: a population-based study on incidence and survival in the Netherlands since 1993. Eur J Cancer 49, 2579–2586 (2013). DISCLOSURES: No relevant relationships by Minira Aslanova, source=Web Response No relevant relationships by Karishma Rupani, source=Web Response No relevant relationships by Sawan Rupani, source=Web Response No relevant relationships by Lesley Wu, source=Web Response