What Lies Beneath: Submucosal Cancer Causing Dysphagia

Abstract

Purpose: A 48-year-old man with a 40 pack-per-year smoking history presented with 1 month of worsening epigastric pain, dysphagia, and weight loss. On admission, computed tomography (CT) scan showed circumferential thickening of the distal esophagus with infiltration into surrounding tissues and diffuse mediastinal and abdominal lymphadenopathy. Bilateral pleural effusions and left-sided pleural nodularity suggestive of metastases were noted in the lung; however, no focal mass was seen. Notably, esophagogastroduodenoscopy (EGD) revealed external compression of the distal esophagus but normal mucosa. Endoscopic ultrasound confirmed thickening of the muscularis propria and the presence of enlarged lymph nodes. Biopsy of these tissues revealed adenocarcinoma with immunohistochemistry (IHC) positive for cytokeratins (CK) 7 and 20 as well as weak positivity for lung cancer-specific TTF-1 and Napsin-A. Positron emission tomography (PET) scan showed uptake in the distal esophagus and mediastinal/abdominal lymph nodes, as well as in the left adrenal gland. No hyper-metabolic activity was seen in the lung. Adrenal mass biopsy was consistent with metastatic adenocarcinoma with staining as above. Diagnostic thoracentesis showed scant atypical cells suspicious for adenocarcinoma; however, paucity of cells prevented adequate immunostaining. The patient was started on folinic acid, 5-fluorouracil, and oxaliplatin. A PEG-tube was placed due to persistent dysphagia despite chemotherapy. Currently, the patient is still undergoing chemotherapy. This presentation highlights a difficult diagnostic case. His symptoms and imaging strongly suggests a primary esophageal tumor; however, EGD showed no mass. Sub-mucosal tumors such as this point instead towards metastasis from an unknown primary, possibly lung or breast. Such cases are rare but often manifest as dysphagia and esophageal narrowing with normal mucosa on EGD as seen in this patient.1,2 IHC and clinical history in this case suggests possible lung cancer. That said, we found no evidence of a primary lung mass on imaging. Hsu et al have described a patient with secondary esophageal cancer arising from occult lung cancer.3 Perhaps this case lends further support to growing evidence that secondary esophageal cancers can and do arise from occult primary tumors.