An unusual congenital lesion in a 26-year-old woman

Multicentric dermatofibrosarcoma protuberans in patients with adenosine deaminase-deficient severe combined immune deficiency

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare malignant skin tumor associated with a characteristic chromosomal translocation (t[17;22][q22;q13]) resulting in the COL1A1-platelet-derived growth factor β(PDGFB) fusion gene. This malignancy is rarely diagnosed in childhood.

OBJECTIVE

We observed an unexpected high incidence of this DFSP in children affected with adenosine deaminase-deficient severe combined immunodeficiency (ADA-SCID) and set out to evaluate the association of these 2 clinical entities.

METHODS

Twelve patients with ADA-SCID were evaluated with a complete dermatologic examination and skin biopsy when indicated. Conventional cytogenetic and molecular analyses (fluorescence in situ hybridization, RT-PCR, or both) were performed when possible.

RESULTS

Eight patients were found to have DFSP. Six patients had multicentric involvement (4-15 lesions), primarily of the trunk and extremities. Most lesions presented as 2- to 15-mm, round atrophic plaques. Nodular lesions were present in 3 patients. In all cases CD34 expression was diffusely positive, and diagnosis was confirmed either by means of cytogenetic analysis, molecular testing, or both. The characteristic DFSP-associated translocation, t(17;22)(q22;q13), was identified in 6 patients; results of fluorescence in situ hybridization were positive for fusion of the COL1A1 and PDGFB loci in 7 patients; and RT-PCR showed the COL1A1-PDGFB fusion transcript in 6 patients.

CONCLUSIONS

We describe a previously unrecognized association between ADA-SCID and DFSP with unique features, such as multicentricity and occurrence in early age. We hypothesize that the t(17;22)(q22;q13) translocation that results in dermal overexpression of PDGFB and favors the development of fibrotic tumors might arise because of the known DNA repair defect in patients with ADA-SCID. Although the natural course of DFSP in the setting of ADA-SCID is unknown, this observation should prompt regular screening for DFSP in patients with ADA-SCID.

Surgical management of congenital dermatofibrosarcoma protuberans

Congenital dermatofibrosarcoma protuberans (DFSP) is a rare tumor with varying clinical presentations that is commonly misdiagnosed. Treatment of congenital DFSP is complicated by delays in diagnosis and its propensity for subclinical spread. Of 61 reported cases, 11 (18%) were treated with Mohs micrographic surgery (MMS) and 46 (75%) were treated with wide local excision (WLE). One case was treated with imatinib, and the remaining 3 did not differentiate between receiving MMS or WLE. In the cases of congenital DFSP treated with MMS the clearance rate was 100% with an average follow-up of 4.3 years. The clearance rate seen with WLE was 89% with an average follow-up period of 1.9 years. The average margins taken during MMS (1.7 cm) were smaller than those taken with WLE (2.8 cm). Fifty percent of cases with available follow-up undergoing WLE required multiple surgeries. Based on superior cure rates with long-term follow-up, smaller surgical margins, and fewer surgical sessions, MMS should be considered as first-line treatment for congenital DFSP.