Leiomyosarcoma of the esophagus, arising from lamina muscularis mucosae, in a combination with microinvasive squamous cell carcinoma-A case report.

Leiomyosarcoma of the esophagus is a very rare disease, accounting for less than 0.5% of malignant esophageal tumors. Esophageal leiomyosarcoma combined with squamous cell carcinoma is even rarer than solitary leiomyosarcoma. To our knowledge, there are less than ten cases of simultaneously diagnosed leiomyosarcoma and squamous cell carcinoma of the esophagus. A 66-year-old male was admitted to our hospital suffering from epigastric pain, asthenia, weight loss, and difficulties when feeding with solid food which had been present for 2 weeks. A computed tomography scan showed a large tumor tissue mass in the mid-to-distal part of the esophagus. The patient underwent robot-assisted surgery-an esophagectomy with esophagogastrostomy. Histologically, the tumor consisted of highly pleomorphic spindle cells with multiple atypical mitosis and necrotic areas. An immunohistochemical examination was performed to distinguish leiomyosarcoma from spindle cell squamous carcinoma or malignant GIST. Tumor cells stained diffusely positive for smooth muscle actin, but negative for p63, CD117, and CKAE1/AE3. Tumor invasion involved mucosa and submucosa, without tunica muscularis propria. Microinvasive well-differentiated squamous cell carcinoma was also noted in the mucosa at the borders between the tumor and the healthy part of the esophagus. The aim of the manuscript is to present an extremely rare case of combined polypoid leiomyosarcoma and microinvasive squamous cell carcinoma of the esophagus, cured by robot-assisted surgical intervention and to emphasize that such cases should be examined carefully, including additional diagnostic tests such as Immunohistochemistry (IHC) in order to define the correct diagnosis.