PMC9399496_01
Histopathologic stains from the inner mass of the right back. HE staining results suggested spindle cell tumor. Low-power (A), medium-power (B), and high-power (C) view demonstrating a partially encapsulated nodular mass without dermal connection. Immunohistochemistry results suggested dermatofibrosarcoma protuberans: CD34 (+) (D), SMA (-) (E), S100 (-) (F), Ki67+ 5-10% (G).
fonc-12-966020-g001.jpg
PMC9399496_01_fonc-12-966020-g001.jpg
f1
The pathological examination was DFSP ( Figure 1 ).
Positron emission tomography/computed tomography (PET/CT) imaging after unplanned resection of DFSP showed an increased radioactive uptake (SUVmax = 5.2) of soft tissue density as well as small nodules in the local subcutaneous soft tissue and have increased metabolic activity.
fonc-12-966020-g002.jpg
PMC9399496_01_fonc-12-966020-g002.jpg
f2
PET/CT was performed in January 2022, and no distal organ or lymphatic metastasis was found ( Figure 2 ).
The ERCC2 intron2 c.105+1 G>C mutation and its effect in RNA splicing. RNA splicing of wild-type (A, B) mutant ERCC2. Each intron has guanine and uracil (GU) at the 5'-end and adenine and guanine (AG) at the 3'-end. 5'ss: 5' splice site; 3' ss: 3' splice site; BP, branch site.
fonc-12-966020-g003.jpg
PMC9399496_01_fonc-12-966020-g003.jpg
f3
The splice-site variant in ERCC2 (c.105+1 G > C) destroys a canonical splice donor site in intron 2, which may leading to an abnormal splicing of mRNA and affect its function ( Figure 3 ).
Sanger sequencing of blood samples from the patient's parents was carried out for family verification: Father (+) (A), Mother (-) (B).
fonc-12-966020-g004.jpg
PMC9399496_01_fonc-12-966020-g004.jpg
f4
The father's diagnosis of polyliposarcoma also harbored this mutation, while variations were not detected in the unaffected mother ( Figure 4 ).