ATYPICAL TERRITORY FOR LUNG ADENOCARCINOMA

Abstract

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Metastasis is a complex aspect of malignancy that is constantly being studied and monitored in advanced cases. In most cases, different types of cancers can be predictable in how they metastasize, and this can affect management and treatment. CASE PRESENTATION: In this case, a 67-year-old male with a past medical history of hypertension, lung mass, and hypothyroidism, presented to the hospital with a chief complaint of constant, excruciating right gluteal pain. A CT scan of the abdomen and pelvis showed a heterogeneous mass within the right gluteus medius muscle along with nodular masses in the abdomen and pelvic regions. In conjunction to these findings, the MRI of pelvis showed that the right gluteal mass was invading into the right piriformis muscle and extending into the pelvic bowel, which is suggestive of a sarcomatous process. A CT guided biopsy of the gluteal mass was performed which revealed poorly differentiated sheets of polygonal cells with vacuolated eosinophilic cytoplasm, pleomorphic nuclei, prominent nucleoli, inflammation and necrosis. These findings along with positive stains for CK7, vimentin, EMA, pankeratin support a diagnosis of pulmonary adenocarcinoma with rhabdoid features. As the patient’s hospital course progressed, collateral notes were obtained from his outpatient office revealing that prior to hospital admission he received an outpatient CT-guided lung biopsy and PET scan. The lung biopsy revealed poorly differentiated adenocarcinoma with rhabdoid morphology and the PET showed metabolic activity in the right gluteal region and adjacent nodes. The patient was scheduled for his first oncology consult one week after his hospital admission, and he was unaware of pertinent details related to his condition. DISCUSSION: In general, skeletal muscle metastasis is a rare occurrence in a non-small cell lung cancer (1). Lung cancer is the leading cause of cancer death and second most common cancer in both genders in the United States. More specifically, adenocarcinoma of the lung is the most prevalent type of lung cancer, accounting for approximately 40% of all cases of lung cancer. Lung cancer is highly malignant with the capability of widespread metastasis. The most common sites of metastasis for lung cancer include: the contralateral lung, adrenal glands, bones, brain and liver. The clinical picture presented was suggestive of sarcoma. The case was reviewed by multiple healthcare professionals who all suspected sarcoma with metastasis to lung, which is common finding in medical practice. It wasn’t until the biopsy was performed that a rare scenario unfolded. CONCLUSIONS: The case reminds us as physicians to be cognizant of the unpredictable nature of lung malignancies and to avoid making premature assumptions. This article supports that biopsy is an imperative diagnostic modality and can help guide treatment. Reference #1: Sridhar KS, Rao RK, Kunhardt B. Skeletal muscle metastases from lung cancer. Cancer. 1987;59:1530–4. DISCLOSURES: No relevant relationships by christian ALMANZAR ZORRILLA, source=Web Response No relevant relationships by Paul Jones, source=Web Response No relevant relationships by Kishankumar Patel, source=Web Response No relevant relationships by Jan Sambataro, source=Web Response No relevant relationships by Vishal Singh, source=Web Response No relevant relationships by Riddhi Upadhyay, source=Web Response