title: Fibrous umbilical polyp: a distinct fasciitis-like proliferation of early childhood with a marked male predominance.
abstract: Benign fibrous lesions of the umbilicus have not been previously studied in a formal series. Clinical and pathologic findings were reviewed in all patients under age 19 with lesions resected from the umbilical region at Children's Hospital (Boston, MA, USA) during an 8-year period. Fourteen lesions were characterized by a well-circumscribed dome-shaped or pedunculated dermal proliferation of moderately cellular fibrous tissue without significant inflammation. Fibroblastic cells were plump to elongate with abundant pale pink cytoplasm. In a subset of lesions, some cells showed atypia or ganglion cell-like morphology. Collagen ranged from sparse to long narrow bundles. Vascularity was sparse and the lesions were nonencapsulated. Loss of rete ridges and basket-weave hyperkeratosis was common in the overlying epidermis. Immunostaining showed focal staining for muscle-specific actin and desmin in a subset of cases and no staining for cytokeratin, epithelial membrane antigen, CD34, or S-100. Age ranged from 3 to 18 months (mean 9 months, median 8 months). Thirteen (93%) patients were boys. Recurrence was not observed. In conclusion, the "fibrous umbilical polyp" is a distinctive lesion of early childhood with an uncertain pathogenesis. It shows a marked predilection for boys, is not rare, and appears to represent a clinicopathologic entity. Perhaps the umbilicus, a midline defect that is normally filled by dense scar tissue after birth, contains unique fibrogenic factors responsible for the development of this distinct lesion.
authors.affiliation: Department of Pathology, Children's Hospital, Boston, Massachusetts 02115, USA. sara.vargas@tch.harvard.edu
authors.forename: S O
authors.initials: SO
authors.lastname: Vargas
mesh_terms: D000008:Abdominal Neoplasms / Q000473:pathology* / Q000601:surgery; D014408:Biomarkers, Tumor; D002455:Cell Division; D005208:Fasciitis / Q000473:pathology*; D005260:Female; D005350:Fibroma / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008297:Male; D011127:Polyps / Q000473:pathology* / Q000601:surgery; D012737:Sex Factors; D014472:Umbilicus / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor