A case of esophageal histoplasmosis mimicking carcinoma on endoscopy.

A 54-year-old woman with progressive and non-acute dysphagia to solid foods, post-feeding vomiting, and weight loss of 10 kg in 1 year. As personal history, she was a former smoker of 60 pack-year, heart transplant for idiopathic dilated cardiomyopathy, and type 2 diabetes. She was on daily use of metformin and immunosuppressive drugs. The laboratory tests were all normal. Upper digestive endoscopy (UDE) revealed in the middle third of the esophagus a lesion of 3 cm presenting atypical rectified vessels, covering 50% of the esophageal lumen, suggestive type 0-IIc+IIa1 (A). The chromoendoscopy with Lugol iodine at 1.25% showed a positive pink sign (B). Biopsies showed esophagitis with mixed inflammatory infiltrate and numerous macrophages (C-upper panel). The Periodic Acid-Schiff staining showed small yeasts compatible with Histoplasma capsulatum, measuring 0.5 to 2.5 µm, within the cytoplasm of macrophages (arrows), with a clear halo (inset, arrows) (C-lower panel). These findings were compatible with esophageal histoplasmosis. Treatment was started with oral Itraconazole 400mg/day. After 3 months, a new UDE with biopsies showed complete esophageal healing. Gastrointestinal histoplasmosis manifests mainly in the small bowel and colon, related to a great amount of lymphoid tissue in these areas. Patients can present with fever, weight loss, abdominal pain and diarrhea. In endoscopy, we may find ulcerations, thickened wall, plaques and pseudopolyps2. It is considered a rare condition, and in only 3% of cases, there is esophageal involvement. This manifestation is mainly in immunosuppressed patients. It can be related to direct involvement of the esophagus or secondary to infiltration of mediastinal nodes2. In endoscopy, ulcerations, inflammatory masses, strictures, and external compressions can be found. This case illustrated the difficulty in differentiating early cancer from an esophageal histoplasmosis.