Clinicopathological study of epithelioid and spindle cell rhabdomysarcoma with EWSR1/FUS-TFCP2 fusion / 中华病理学杂志

Objective: To investigate the clinicopathological and genetic features of epithelioid and spindle cell rhabdomysarcoma with EWSR1-TFCP2 or FUS-TFCP2 fusion. Methods: The clinical, morphological and immunohistochemical features of 14 cases of epithelioid and spindle cell rhabdomysarcoma with EWSR1-TFCP2 or FUS-TFCP2 fusion diagnosed from January 2019 to December 2022 in the Department of Pathology, Foshan Traditional Chinese Medicine Hospital, Foshan, China were retrospectively analyzed. The cases were all subject to FISH or next generation sequencing for analysis of molecular genetic features. The literature was reviewed. Results: There were 5 males and 9 females, with the age at presentation ranging from 6 to 36 years (mean, 22 years). Tumors occurred in the head and neck (9 cases), pelvic region (2 cases), bladder (one case), right humerus (one case), and the abdominal wall, humerus and pubic at the same time (one case). Presenting symptoms varied by location but often included pain or discomfort. Most of the patients showed aggressive radiographic features with soft tissue extension. The tumors had a median size of 6.6 cm (range, 2-23 cm). The tumors were poorly defined and irregularly shaped. Microscopic examination showed diffuse proliferation of spindle or epithelioid cells. While morphologically high-grade tumors displayed obvious cytological atypia, a high mitotic count and tumor necrosis, low-grade tumors grew in sheets and fascicles composed of spindle, epithelioid cells with moderate or abundant amounts of eosinophilic cytoplasm, without pronounced cytological atypia. The tumor cells expressed Desmin, MyoD1, and Myogenin, as well as ALK, EMA, and CKpan. EWSR1/FUS-TFCP2 gene fusion was detected in 14 cases with next generation sequencing and confirmed by FISH. Six cases had EWSR1-TFCP2 fusions and 8 cases showed FUS-TFCP2 fusions. Follow-up information was available in 13 patients, ranged from 5 to 37 months. At the end of follow-up period, 7 patients died of the disease. Six patients were alive:two cases had local recurrences and metastases, two cases of recurrences, one case of metastasis and one case without recurrences and metastasis. Conclusions: Epithelioid and spindle cell rhabdomysarcomas with EWSR1-TFCP2 or FUS-TFCP2 fusion show a very aggressive clinical course, and more commonly occur in the head and neck. Their genetic hallmark is the presence of EWSR1/FUS-TFCP2 fusions. Familiarity with its clinicopathological characteristics is helpful in avoiding misdiagnoses.

Practical Value of Environment-friendly Sample Release Agent Combined with Ultrasound in the Preparation of Pathological Tissue Sections / 中山大学学报(医学科学版)

ObjectiveTo explore the practical value of environment-friendly sample release agent combined with ultrasound in the preparation of pathological tissue sections. MethodsFrom February 2013 to December 2022， 2 518 pathological specimens submitted by Foshan Municipal Hospital of Traditional Chinese Medicine were selected as the study objects. Two samples of the same specimen were randomly divided into two groups： the environment-friendly fast group， in which the pathological tissue sections were made by using the environment-friendly sample release agent combined with ultrasound； and the traditional group， in which formaldehyde， ethanol and xylene were used to make slices in the conventional way. The differences of hematoxylin （HE） staining effect， immunohistochemistry （IHC） staining effect and MDM2 gene detection result of atypical lipomatous tumor/highly differentiated liposarcoma （ALT/WDL） tissue sections between the two groups were compared. Results① The wax of the two groups' pathological tissues was dehydrated well and the tissue hardness was moderate. After HE staining， the sections of the two groups were intact， without cracks and tremor marks， and the contrast between nucleus and cytoplasm was appropriate， with good transparency， uniform staining， and no tissue loss. The excellent rate and score of HE staining in the environmental fast group were higher than those in the traditional group， but the difference was not statistically significant （χ2 = 3.125，P1 = 0.070；t = 0.965，P2 = 0.334）. ②After IHC staining of the two groups of sections， the positive location of the cells was accurate， the staining was specific and uniform， the staining intensity was moderate， the staining sensitivity was good， and there was no tissue loss. The excellent rate of IHC staining and the positive rate of IHC staining in the environmental fast group were lower than those in the traditional group， but the difference was not statistically significant （χ12 = 2.769，P1 = 0.092；χ22 = 0.800，P2 = 0.375）. ③The background and outline of the two groups of WDL tissue sections were clear， the staining was uniform， the cells were clear and visible， the nuclear boundary was clear， the hybridization signal was clear and bright under the background fluorescence， and there was no miscellaneous signal. The two groups of sections were hybridized successfully， and MDM2 showed positive amplification. The number of cells successfully hybridized in the environment-friendly fast group was lower than that in the traditional group， but the difference was not statistically significant （t = 1.414，P = 0.230）. ConclusionsThe tissue treatment method of using environment-friendly sample release agent combined with ultrasound can ensure the detection effect of HE staining， IHC staining and MDM2 gene detection of pathological tissue sections， and is more efficient and environment-friendly， suitable for promotion and use in hospitals at all levels.