In the store-and-forward teledermatology modality, there is a transfer of patient medical information electronically (including history and visual data) obtained in one location to a provider who is in another location (Roman & Jacob, 2015). The construct of the Teledermatology Viewpoint column is such that cases are presented in a standardized teledermatology reader format reflective of an actual teledermatology report.
HISTORY
Chief Complaint
Presenting for diagnosis of a lesion.
History of Present Illness
A 50-year-old woman presents with a firm solitary asymptomatic lesion on her buttock that she says has grown over the last 2 years. Prior treatment: none. Prior biopsy: none. She has no personal or family history of skin cancer or melanoma.
IMAGE QUALITY ASSESSMENT
Fully satisfactory.
TELEDERMATOLOGY IMAGING READER REPORT1
There is one image provided with this consult (Figure 1). The image shows a red-brown, irregular asymmetrical plaque on the right buttock.
INTERPRETATION OF IMAGES
Findings
The reddish-brown, protuberant firm plaque is concerning for dermatofibrosarcoma protuberans (DFSP). Differential diagnosis includes keloid, dermatofibroma, melanoma, and hypertrophic scar.
RECOMMENDATIONS
Refer to dermatology for a face-to-face evaluation and biopsy.
CLINICAL PEARL
DFSP is a rare type of skin cancer that typically occurs in middle-aged individuals but can also occur congenitally (Shin, Bordeaux, Bernhard, & Tan, 2017). Commonly, DFSP may appear as an atrophic, scar-like purple plaque and may be painful or ulcerated (Shin et al., 2017). In some patients, there may be a history of trauma at the site of the DFSP lesion. DFSP is classified as a low-grade sarcoma that appears as a slow-growing, asymptomatic reddish-brown plaque with irregular, hard, rubbery nodules. The tumors have a predilection for the trunk or lower extremity and are slightly more common in women. Notably, they are almost twice as common in individuals with African descent (Shin et al., 2017). Studies have shown that the pathogenesis of DFSP involves a T translocation in 90% of the genes that fuse Collagen Type I Alpha I gene and platelet-derived growth factor beta (Li et al., 2017).
For confirmatory diagnosis of a DFSP, an incisional or excisional skin biopsy that includes subcutaneous tissue should be performed. The stains used to differentiate melanoma, dermatofibroma, and DFSP can be seen in Table 1. Histologically, DFSP can be seen to have diffuse staining of Factor XIIIa in the cells around the edges as well as a positive CD44 stain. Fluorescence in situ hybridization and reverse transcription polymerase chain reaction tests can be used to detect the T translocation and fusion of Collagen Type I Alpha I and platelet-derived growth factor beta (Li et al., 2017).
Definitive treatment for DFSP includes surgical excision with clear 2- to 4-cm histological margins or Mohs micrographic surgery. One study showed that excision has a 7.3% recurrence rate, whereas Mohs has a ~1% recurrence rate, likely because of the asymmetric growth patterns and subclinical extensions (Shin et al., 2017). Notably, DFSP also has a high recurrence rate (within 3 years), and therefore adjunct radiation therapy has been reported to help decrease the recurrence rate (Shin et al., 2017). Because of the high recurrence rate that usually occurs within 3 years, it is recommended that patients follow-up every 3-6 months for the first three years.
REFERENCES