Fibroblastic Connective Tissue Nevus: A New Type of Dermal Fibroblastic/Myofibroblastic Lesion

CD34 positivity can help to confirm this diagnosis.

Dermal fibroblastic/myofibroblastic proliferation characterizes a range of lesions with a common lineage but differing histology, clinical context, and behavior. Connective tissue nevus (CTN) is one such lesion; it can occur sporadically or associated with syndromes such as storiform collagenoma associated with Cowden syndrome. These authors analyzed the clinicopathologic presentation of a new CTN variant they call fibroblastic connective tissue nevus (FCTN).

In 25 cases (median age, 10 years; female:male ratio, 2:1)from a tertiary institution, the most frequent clinical presentation was of a single, slowly growing, painless plaque or nodule that had been present for a median of 1 year, with a mean size of 0.6 cm, and sited most frequently on the trunk. Histology demonstrated a proliferation of fibroblastic/myofibroblastic cells arranged in fascicles and entrapping appendages at the level of the reticular dermis, with extension to the subcutis. Epidermal changes like papillomatous hyperplasia occurred in 70% of samples, and adipose tissue in the dermis was seen in 61%. No pleomorphism or mitotic activity was identified. More than 80% were positive for CD34, and 47% were weakly positive for smooth muscle actin. During an average follow-up of 4 years, no local recurrences or metastasis was seen.

CITATION(S):

de Feraudy S and Fletcher CDM. Fibroblastic connective tissue nevus: A rare cutaneous lesion analyzed in a series of 25 cases. Am J Surg Pathol 2012 Oct; 36:1509.