Clinical and histopathological characteristics of atrophic pigmented dermatofibrosarcoma protuberans: A retrospective study of 14 cases

Abstract

Background: Dermatofibrosarcoma protuberans (DFSP) invades the dermis and subcutaneous tissue. DFSP with both atrophic and pigmentary (AP-DFSP) features is extremely rare and the clinical characteristics remain unknown. Here we aim to characterize the clinical, histopathologic and prognostic features of AP-DFSP.

Methods: Fourteen cases of patients with AP-DFSP were collected from our institution and published online, including four unreported cases and ten published cases. The clinical appearance, immunohistochemical markers, treatment, and prognosis were analyzed to obtain the clinical and histological features.

Results: There were six males and eight females with a mean age of 25 years old. The vast majority of lesions appeared in the trunk (10/14, 71.4 %) and limbs (3/14, 21.4 %), whereas a minority involved the infraorbital area (1/14, 7.2 %). The most typical manifestation was a depressed plaque-like lesion with fuchsia and bluish color. Histologically, AP-DFSP harbored both atrophic and pigmented features, presenting with a thinner dermis and intradermal melanin granules. Immunohistochemically, CD34 and vimentin were positive while S100 was negative in tumor tissues. The Ki67 index was less than 10 %. Thirteen of fourteen patients had complete excision surgery and follow-ups showed no local recurrence or distant metastasis.

Conclusion: Compared to DFSP, AP-DFSP shows more benign clinical and histological features with a good prognosis. Surgical intervention leads to a significant reduction in tumor burden and dramatically increases the likelihood of complete remission.

Keywords: Atrophic pigmented dermatofibrosarcoma protuberans; Good prognosis; Indolent character.

Fig. 1

Clinical features of our four AP- DFSP patients. (a–b) Purple pigmented atrophic patch on left supraclavicular fossa of case 1 and 2. (c) Bluish plaque-like lesion on right lower back of case 3. (d) Dark violet atrophic patch on right upper back of case 4. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2

Histological features of AP-DFSP. (a–d) Spindle cell proliferation in the dermis and sporadic pigmented cells of the four cases. Scale bar = 200 μm. (e) Horizontally oriented fascicles in case 1. Scale bar = 25 μm. (f) Subcutaneous infiltration in case 2. Scale bar = 25 μm. (g) The whorled pattern of spindle cells in case 3. Scale bar = 25 μm. (g) Horizontally oriented fascicles and subcutaneous infiltration in case 4. Scale bar = 25 μm.

Fig. 3

Immunohistochemical characteristics of our four AP-DFSP cases. (a–b) Diffuse and strong expression of CD34 and vimentin in each of the four cases. (c) Positive staining of S100 in pigmented cells and negative staining in tumor in the four cases. (d) Ki67 expression in the four cases. Scale bar in all images = 200 μm.

The dermis thickness of corresponding healthy skin (HC) regions at the same anatomical sites. (a) HE staining of HCs. Scale bar = 1 mm (b) Dermal thickness changes between cases and comparative healthy controls. ∗∗∗∗p < 0.0001, student's two-tailed t-test. Error bars = SD.