PMC10368097_01
Image and operative findings and pathological findings at a nearby hospital. a Tumor appearance (white arrows). The tumor was a superficial, elastic-soft lump without a notable change in skin color. b-d MRI findings of the primary tumor. The tumor was a relatively well-defined lesion in the subcutaneous layer, measuring 47 mm in diameter, with homogenously low signal on T1-weighted images (b), homogenously high signal on T2-weighted images (c), and homogenously high signal on T1-weighted gadolinium-enhanced images (d). e, f Operative findings at the nearby hospital. The tumor was marginally excised upon initial surgery. The tumor was not excised with the overlying skin and was macroscopically exposed through the tumor capsule. g, h Hematoxylin and eosin (HE) staining showed spindle cell proliferation. The margin was positive microscopically. Low-power field (g) and high-power field (h). i An immunohistochemical study showed the tumor cells were positive for CD34. j Fluorescent in situ hybridization (FISH) showed positive for PDGFB rearrangement. The red spots indicated the presence of the COL1A1 gene. The green spots showed the presence of the PDGFB gene. The chromosome that was labeled with yellow spots was the one where rearrangement was present.
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F1
Her parents first noticed the superficial elastic-soft lump when she was 8 months old (Fig. 1a). Although the MRI findings strongly suggested a malignant tumor in a retrospective review (Fig. 1b-d), the mass was interpreted as a benign lesion and was excised unplanned at the age of 13 months (Fig. 1e, f). Precise pathological examination revealed spindle cell proliferation and that the mass was positive for CD34 by immunohistochemistry and positive for PDGFB rearrangement by fluorescence in situ hybridization, indicating the final diagnosis of DFSP (Fig. 1g-j).
Findings upon referral to our hospital. a Physical examination at presentation to our hospital revealed she had a scar on her back measuring 7 cm in length without any palpable nodules beneath. b MRI findings after primary surgery. T1-weighted images with gadolinium enhancement suggested a residual lesion at the primary site (white arrows).
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Upon referral, physical examination revealed a scar on the patient's back measuring 7 cm in length without underlying palpable nodules (Fig. 2a). MRI suggested a residual tumor on gadolinium enhancement (Fig. 2b), and computed tomography revealed no metastatic lesions.
Operative and pathological findings. a Preoperative planning. We planned to perform additional wide resection 3 months following the unplanned excision with a 3-cm margin in the horizontal direction and resected the underlying fascia for the margin in the vertical direction. b Massive skin defect measuring 15 x 11 cm in diameter after additional wide resection of the lesion. c A three-point anchoring suture was done for primary closure without skin graft or flap coverage. d, e HE staining of the specimen at low-power field (d) and at high-power field (e) revealed the presence of spindle cell proliferation. There was no fascial invasion in the deep direction, and the horizontal margin was negative at 14 mm. f, g Immunohistochemical study at low-power field (f) and at high-power field (g) showed the tumor cells were positive for CD34, CD68, and PDGFbeta, which indicated DFSP (data not shown).
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Primary closure was achieved without requiring a secondary graft or flap coverage for the massive skin defect measuring 15 x 11 cm (Fig. 3a-c). The pathological findings revealed the presence of residual tumor cells but the absence of tumor cells at the surgical margin (Fig. 3d-g).