PULMONARY NODULE IN A PATIENT WITH REMOTE HISTORY OF BREAST CANCER: AMBIGUOUS IMAGING AND HISTOLOGY CAN LEAD YOU ASTRAY

Abstract

SESSION TITLE: Lung Pathology 2 SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: When a pulmonary nodule is seen on surveillance imaging of a patient with a remote history of breast cancer, it can be tempting to assume that the lung nodule is pulmonary metastasis. We herein describe a case of right middle lobe (RML) typical carcinoid and simultaneous recurrence of breast cancer (ER positive, PR positive, HER2 negative) involving the right supraclavicular lymph node that was challenging to determine a treatment regimen due to ambiguous imaging and histology results. CASE PRESENTATION: We present a 63-year-old woman, who was diagnosed with Stage II-B (T2N1M0) breast carcinoma in 2003. She underwent right mastectomy, radiation to the right chest wall, and tamoxifen therapy. Annual surveillance in 2016 revealed an increase in tumor markers. Computed Tomography (CT) revealed a 1.5-cm RML nodule near the hilum, with a standardized uptake value of 2.8 on subsequent Positron Emission Tomography (PET) scan. The patient underwent navigation bronchoscopy with biopsy of the RML nodule. Pathology of the RML nodule revealed uniform tumor cells with minimal atypia expressing chromogranin, synaptophysin and TTF1-Napsin but not ER, mammaglobin or GATA3. Octreotide scan was performed, which oddly demonstrated increased activity in a small lymph node in the right supraclavicular fossa. After thoracic tumor board discussion, she underwent excisional biopsy of the 1.3-cm lymph node, which revealed metastatic breast cancer. DISCUSSION: Carcinoid tumors are expected to be positive on Octreotide scan and negative on PET, whereas breast cancer metastasis should be positive on PET and negative on Octreotide scan. However, it is important to note that these findings are not always guaranteed. In one large study, Octreotide scan localized only 86% of carcinoids (Krenning et al, 1993). Additionally, the specificity of PET scan for neuroendocrine tumors (NETs) is dependent on the level of malignancy of the tumor; with PET scans, high grade NETs are more likely to be localized, whereas low grade NETs (typical carcinoid), are more likely to be missed (Maxwell et al, 2015). Given that imaging findings differed from what was expected, the case was discussed with a multidisciplinary tumor board and investigated further with histopathology before determining a treatment course. During the tumor board meeting, neuroendocrine differentiation of breast cancer was discussed, however, it was determined that the pathology and immunohistochemistry of the RML nodule was suggestive of typical carcinoid despite the imaging findings. CONCLUSIONS: In the setting where tumor imaging findings are different from what is expected, it is important to discuss the case in a multidisciplinary tumor board and investigate further with histopathology before determining a treatment course. When imaging and histopathology results conflict with one another, treatment should be based on histopathology findings rather than imaging. Reference #1: Krenning EP, Kwekkeboom DJ, Bakker WH, et al. Somatostatin receptor scintigraphy with [111In-DTPA-D-Phe1]- and [123I-Tyr3]-octreotide: the Rotterdam experience with more than 1000 patients. Eur. J. Nucl. Med. 1993;20(8):716–731. Reference #2: Maxwell, Jessica E, and James R Howe. “Imaging in Neuroendocrine Tumors: an Update for the Clinician.” International Journal of Endocrine Oncology, vol. 2, no. 2, 2015, pp. 159–168., https://doi.org/10.2217/ije.14.40. DISCLOSURES: No relevant relationships by Matthew Gerling, source=Web Response No relevant relationships by Ali Saeed, source=Web Response No relevant relationships by Jessica Zimmerberg-Helms, source=Web Response