ABSTRACT
Extranodal follicular dendritic cell sarcoma (ENFDCS) is a rare hematolymphoid tumor, masquerading as soft tissue sarcoma on initial histological examination. So, for its confirmation, the application of immunohistochemistry (IHC) is of paramount importance. Over the years there has been a major shift in the demography of follicular dendritic cell sarcoma (FDCS), with a rise in the number of extranodal cases. Herein we report a case of ENFDCS presenting as a rectal polyp, who had a history of intermittent bleeding per rectum and passage of fleshy mass while defecation. As these tumors share an overlapping morphology with other spindle cell tumors and can occur at unpredictable locations, they pose a diagnostic challenge, especially for young pathologists.
Subject(s)
Dendritic Cell Sarcoma, Follicular/pathology , Polyps/diagnosis , Rectal Neoplasms/diagnosis , Sarcoma/diagnosis , Biomarkers, Tumor/analysis , Colonoscopy , Dendritic Cell Sarcoma, Follicular/diagnosis , Diagnosis, Differential , Humans , Immunohistochemistry , Male , Soft Tissue Neoplasms/diagnosis , Young AdultABSTRACT
Inflammatory pseudotumor-like follicular/fibroblastic dendritic cell sarcoma (IPT-like FFDCS) is a rare, indolent neoplasm that occurs in the spleen or liver and harbors Epstein-Barr virus (EBV) integrated into the host genome. The molecular genetic characteristics of IPT-like FFDCS have not been well studied and there are no established and actionable molecular features to guide treatment decisions or diagnosis beyond the recognition of viral genome integration. We subjected two cases of IPT-like FFDCS to a comprehensive next-generation sequencing analysis. Several variants of uncertain clinical significance were detected in both tumors. No variants of potential or strong clinical significance were detected within the targeted regions of the evaluated genes. Additionally, no fusion events were detected involving the genes in either tumor. The performed molecular analysis identified no genetic aberrations in IPT-like FFDCS and its genomic landscape remains, with the exception of a monoclonal EBV gene, largely undefined.