[747] Inflammatory Pseudotumor of the Esophagus: A Report of 5 Cases
K Sy, S Al-Haddad, J Parfitt, CJ Streutker. University of Toronto, Toronto, ON, Canada; St. Michael's Hospital, Toronto, ON, Canada; London Health Sciences Centre, University of Western Ontario, London, ON, Canada
Background: Inflammatory pseudotumors of the esophagus are rare lesions which are frequently misdiagnosed as malignancies, particularly sarcomas, due to the marked atypia of the stromal cells. These lesions most often arise in a background of reflux or pill esophagitis, but their etiology is uncertain. Due to their benign behaviour, it is important to distinguish them from true malignancies.
Design: We present 5 cases of inflammatory pseudotumors of the esophagus. The cases occurred in 3 females and 2 males with a mean age of 60.8 years. Of the 5 cases, 4 were consult cases from outside our hospital which had all been diagnosed as sarcomas elsewhere and sent to our centre for second opinion or for consideration of mucosal resection therapy. Clinical presentations were variable with one presenting with difficulty swallowing, one presenting with abdominal pain and weight loss and one with an upper gastrointestinal bleed. All cases on endoscopy identified nodules or masses in the distal esophagus.
Results: Microscopically, the lamina propria in all 5 cases contained chronic inflammation, increased vascularity and granulation tissue. 3/5 cases showed mucosal ulceration and acute inflammation within the epithelium. Markedly atypical and pleomorphic stromal cells with prominent nucleoli were identified in 5/5 cases. Immunohistochemistry performed on 4 of the cases (Table 1) showed uniform positivity for vimentin: the cells were negative for all other markers. Follow-up endoscopic mucosal resection was done in one patient and a small area of resolving inflammation and stromal changes was noted.
| PATIENT | VIMENTIN | SMA | AE1/AE3 | CD34 | S100/HMB45 | CD45 | CD30 |
| 1 | 3+ | NA | 0 | NA | 0 | 0 | 0 |
| 2 | 3+ | 0 | 0 | NA | NA | NA | NA |
| 3 | 3+ | 1+ | 0 | 0 | NA | NA | NA |
| 4 | 2+ | NA | 0 | NA | 0 | NA | NA |