A 27-year-old Chinese woman presented with menstrual volume increase for three years and vaginal bleeding for 24 days. Enhanced arterial phase CT showed that the volume of the uterus significantly increased, and space-occupying lesions could be seen in the uterus with a size of about 9.5 cm × 8.5 cm × 8 cm. A mass with a mixed density shadow was observed in the uterus, and the boundary was unclear (Fig. 1-A). The size of the uterus was 12 cm × 10 cm ×9 cm, the depth of the uterine cavity was 8 cm, and the thickness of the endometrium was 0.2–0.3 cm. There was a large mass in the uterine cavity at a size of 9 cm × 8 cm × 8 cm; the section was grey white and grey red. The bilateral ovaries and oviduct were not involved by SDUS in Enhanced arterial phase CT and surgery (Fig. 1-B).
During surgery, diffuse uterus enlargement was identified, about the size of 16 weeks of gestation; the surface of the uterus had a hard texture with many hard nodules, each with a diameter of about 1 cm. When a cut was made into the uterine cavity, the lesion had no boundary with the normal myometrium and were easily broken. The adhesion between the left bladder and the lower uterine segment was dense, and the tumour had infiltrated into the serosal surface in the lower-left anterior wall of the uterus. No lesions were found in bilateral appendages or other organs.
Haematoxylin and eosin staining was performed. Microscopically, the tumour cells were diffusely distributed, displaying flake or acinar shapes. SDUS tumour cells in some areas had lost adhesion, and some SDUS tumour tissues grew around and invaded the blood vessels (Fig. 2-A). Extensive necrosis was observed (Fig. 2-B). Vascular and normal endometrial gland invasion was observed (Fig. 2-C). The tumour cells were epithelioid and had eosinophilic cytoplasm, and some cells showed nuclear deviation towards the cytoplasm. These cells were rhabdoid with round or oval nuclei (Fig. 2-D). The results of immunohistochemistry of the Ki-67 proliferation marker showed a high percentage (60%) of cell staining, with the expression of INI-1, the local expression of CD10, and the lack of expression of BRG1, CK (Pan), SYN, Desmin, and ER (Fig. 2).
The NGS was conducted at Geneseeq Technology Inc. (Nanjing, China). Formalin-fixed paraffin-embedded sections of the uterine tumour were subjected to comprehensive NGS analysis with 425 predefined related genes. Data were sequentially analysed by an effective bioinformatics process. Germline mutations were filtered out by comparing to patient’s whole blood controls. In our case, the genetic analysis result showed that no germline mutation was detected in her family. A SMARCA4 splicing mutation, c.355 + 190_616del, was detected at a MAF of 86.4% in the tumour sample, accompanied by a SMARCA4 frameshift mutation p.H571Gfs (45.8%). TMB: 1.1 mutations/MB (Fig. 3). Our NGS test includes MMR, MSI, PTEN, PIK3CA, TP53, beta-catenin, etc. Our NGS test report showed SMARCB1, CTNNBI, MMR, MSI, PTEN, PIK3CA, TP53 were negative. In conclusion, a clinical diagnosis of SDUS was confirmed by expert consultation.
The Multiple Immunofluorescent Staining was conducted at Genecast Biotechnology Co. Ltd. (Beijing, China). Briefly, 4-µm thick sections were cut from SDUS tissues for analysis. Primary antibodies for PD-L1(1:25), CD68 (1:500), PD-1 (1:50) were incubated for 1 h at 25℃, and CD8 antibody (1:100) was incubated overnight at 4℃. The results showed that there were some infiltrating immune cells expressing CD8(+,0.92%) and CD68(+,0.2%) in SDUS tissues. A few cells expressing PD-1(+,0.06%) and PD-L1(+,0.06%) were detected by immunofluorescence (Fig. 4). The results showed that some of the immune cells expressing CD3 and CD8 had infiltrated into SDUS tissues, but no PD-L1 expression was detected (Fig. 4). Approximately 27 T-cells per high power field (HPF) had infiltrated into SDUS tissues. The results showed that SDUS had immunogenicity. The antibody information is shown in Table 1.
Table 1
Antibody clones, and suppliers used for immune stains.
Antibody
|
Clone
|
Supplier
|
BRG1
|
E8V5B
|
ZSGB-BIO, Co.Ltd,China
|
CD10
|
MX002
|
Fuzhou Maixin biotech.Co.Ltd,China
|
ER
|
SP1
|
Fuzhou Maixin biotech.Co.Ltd,China
|
Myogenin
|
F5D
|
Fuzhou Maixin biotech.Co.Ltd,China
|
Desmin
|
MX046
|
Fuzhou Maixin biotech.Co.Ltd,China
|
CKpan
|
AE1/AE3
|
Fuzhou Maixin biotech.Co.Ltd,China
|
Ki67
|
MX006
|
Fuzhou Maixin biotech.Co.Ltd,China
|
Syn
|
MX038
|
Fuzhou Maixin biotech.Co.Ltd,China
|
SMA
|
1A4
|
Fuzhou Maixin biotech.Co.Ltd,China
|
CD34
|
QBEnd/10
|
Fuzhou Maixin biotech.Co.Ltd,China
|
CD3
|
SP7
|
Fuzhou Maixin biotech.Co.Ltd,China
|
CD8
|
SP16
|
Fuzhou Maixin biotech.Co.Ltd,China
|
CD99
|
O13
|
Fuzhou Maixin biotech.Co.Ltd,China
|
INI1
|
MRQ-27
|
Fuzhou Maixin biotech.Co.Ltd,China
|
PD-L1
|
22C3
|
Dako, Carpinteria, CA, USA
|
PD1
|
ZM-0381
|
ZSGB-BIO, Co.Ltd,China
|
CD68
|
ZM-0060
|
ZSGB-BIO, Co.Ltd,China
|
Calponin
|
MX023
|
Fuzhou Maixin biotech.Co.Ltd,China
|
In our case, the tumour stage was pt3bnxmx. the patient underwent hysterectomy and bilateral salpingo-oophorectomy, then received gemcitabine and docetaxel chemotherapy for 4 cycles. After positron emission tomography, computed tomography (PET-CT) examination, it was found that there were hypermetabolic signals in the left iliac fossa and pelvic cavity of the patient, suggesting that the tumour had a trend of further deterioration (Fig. 5). The treatment plan was changed to epirubicin and ifosfamide chemotherapy. During 3 cycles of treatment, the patient eventually gave up on chemotherapy due to severe side effects. The patient is still alive and displayed the left iliac fossa lesion enlargement in the 6-month follow-up check.