[485] Connective Tissue Nevus: A Rare Lesion Analyzed in a Series of 25 Cases

Sebastien de Feraudy, Christopher DM Fletcher. Brigham and Women's Hospital and Harvard Medical School, Boston, MA

Background: Connective tissue nevus (CTN) is an unusual benign cutaneous lesion that remains poorly defined in the literature. The purpose of this study was to characterize the clinicopathologic and immunohistochemical features of CTN.
Design: 25 cases of CTN were retrieved from consult files. Clinical, pathologic and immunohistochemical features were evaluated. Clinical follow-up was obtained from medical records and referring physicians. Descriptive statistical analysis was performed.
Results: Sixteen patients were female (64%) and 9 were male (36%), with age ranging from 1.5 months to 58 years (median 10 years). Most patients presented with a slowly growing, painless plaque-like or nodular skin lesion (median size 0.6. cm, grossly). Eleven cases (44 %) arose on the trunk, 9 (36%) on the head and neck, and 5 (20 %) on limbs. All tumors showed poor circumscription and were situated primarily in the reticular and deep dermis, extending into superficial subcutis in 13 cases (52%). The lesion was associated with papillomatous epidermis in 17 cases (70%) and presence of adipose tissue in the reticular dermis in 14 cases (60.9%). All tumors were composed of a disorderly proliferation of bland intradermal fibroblastic cells with palely eosinophilic cytoplasm and tapering nuclei, with no significant cytologic atypia or pleomorphism, arranged in short-intersecting fascicles and entrapping appendages. No mitoses were identified. Immunostains showed positivity for CD34 in 20 of 23 cases (87%) and weak focal positivity for smooth muscle actin (SMA) in 9 of 19 cases (47%). No case stained for desmin (0 of 11 cases). Clinical follow-up was obtained for 13 patients. No tumor recurred locally, even when surgical excision was incomplete. No lesion metastasized.
Conclusions: CTN occurs most commonly as a plaque on the trunk and head/neck of children, involves deep dermis and superficial subcutis, and stains mainly for CD34. CTN most likely represents a localized development anomaly; it is entirely benign and should not be confused with dermatofibrosarcoma protuberans or other neoplasms.
Category: Dermatopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 97, Tuesday Morning

 

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