Abstract
Diffusely infiltrative squamous cell carcinoma of the esophagus is rare and difficult to diagnose. CASE PRESENTATION: The patient was a 75-year-old woman whose chief complaints were dysphagia and upper abdominal pain. Esophagogastroduodenoscopy and biopsy revealed squamous cell carcinoma at the abdominal esophagus. After neoadjuvant chemotherapy, esophagogastroduodenoscopy showed diffuse thickening and poor distensibility of the stomach wall. We suspected scirrhous gastric cancer and performed multiple biopsies, which revealed no evidence of malignancy. We then performed staging laparoscopy. There were no apparent changes in the serous membrane of the stomach, but peritoneal lavage cytology revealed squamous cell carcinoma. Thus, we made a diagnosis of squamous cell carcinoma of the esophagus with diffuse invasion of the stomach. Intraoperative pathological diagnosis revealed that there was greater diffuse submucosal invasion of the oral esophagus than we expected, and we had to resect the esophagus at the level of the middle thoracic esophagus. Despite multidisciplinary treatment (surgery, chemotherapy, and radiotherapy), the patient died 20 months after the initial diagnosis. CLINICAL DISCUSSION: In this case, although biopsy did not lead to a diagnosis, peritoneal lavage cytology led to the correct diagnosis. Moreover, it was impossible to preoperatively predict the exact extent of the expansion because of diffuse submucosal invasion. CONCLUSION: When diffusely infiltrative squamous cell carcinoma of the esophagus is suspected, peritoneal lavage cytology may be useful for confirming the diagnosis; however, it should be assumed that accurate preoperative evaluation of the range of diffusely infiltrative squamous cell carcinoma is difficult.