C0708 - A Rare Case of Primary Lung Adenocarcinoma With Biopsy-Proven Gastric Metastases

Javaria Tehzeeb, MBBS¹, Fatima Mahmood, MBBS¹, Syed Mehdi, MBBS², Hafiza Hareem Waqar, MBBS^1
1Albany Medical Center, Albany, NY; ²Albany Stratton VA Medical Center, Albany, NY

Introduction: Gastrointestinal (GI) metastases from lung cancer are extremely rare. Lung adenocarcinomas are associated with the least likelihood of spreading to the GI tract, and the gastric cavity is a rare site to be involved. Hence, we find it of interest to present a rare case of primary lung adenocarcinoma with biopsy-proven gastric metastases.

Case Description/Methods: A 67-year-old male with 120 pack-year smoking history presented with back and abdominal pain, and productive cough for several months. CT abdomen and pelvis showed numerous lytic lesions in the pelvis and thoracic spine, and an L1 vertebral mass. Further scans revealed ground-glass opacity in the right lung and extensive brain and meningeal enhancement. Biopsies of random gastric mucosa and L1 mass were consistent with metastatic adenocarcinoma with immunohistochemical testing staining positive for Napsin A, TTF1, CK7, and CK19. Peripheral blood was sent for Foundation one testing and no actionable mutations were found. He was diagnosed with Stage IVb lung adenocarcinoma and received 4 cycles of carboplatin, pemetrexed and pembrolizumab and radiation therapy to whole brain, followed by maintenance chemotherapy with pemetrexed and pembrolizumab. Unfortunately, surveillance PET scans revealed worsening tumor burden and currently he is undergoing palliative chemotherapy and radiation

Discussion: As novel treatments are discovered, and survival rates increase, the spectrum of pathology of lung cancer has also evolved. Lung cancer commonly metastasize to the bones and brain; however, the GI tract is increasingly being noted as a potential metastatic site. Small cell lung cancer is the most common subtype of lung cancer associated with GI metastases, predominantly involving small intestine. Very few cases of lung adenocarcinoma with stomach metastases have been reported. Diagnosis of the primary lesion can be tricky in cases where initial presentation includes GI complaints. Further, while metastases to other GI sites might present early as obstruction or perforation, gastric metastases can remain clinically silent for long durations due to the anatomy of the gastric wall and size of the gastric cavity, and hemorrhage in this location can be occult and more extensive. The metastatic involvement of rare sites is mostly seen in aggressive and advanced malignancy. Reporting these rare cases remains essential to substantiate the index of suspicion, which is paramount to early diagnosis and better clinical outcomes.



Disclosures:


Javaria Tehzeeb, MBBS¹, Fatima Mahmood, MBBS¹, Syed Mehdi, MBBS², Hafiza Hareem Waqar, MBBS¹. C0708 - A Rare Case of Primary Lung Adenocarcinoma With Biopsy-Proven Gastric Metastases, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.