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.

Clinical feature difference between juvenile amyotrophic lateral sclerosis with SPTLC1 and FUS mutations / 中华医学杂志(英文版)

BACKGROUND@#Juvenile amyotrophic lateral sclerosis (JALS) is an uncommon form of amyotrophic lateral sclerosis whose age at onset (AAO) is defined as prior to 25 years. FUS mutations are the most common cause of JALS. SPTLC1 was recently identified as a disease-causative gene for JALS, which has rarely been reported in Asian populations. Little is known regarding the difference in clinical features between JALS patients carrying FUS and SPTLC1 mutations. This study aimed to screen mutations in JALS patients and to compare the clinical features between JALS patients with FUS and SPTLC1 mutations.@*METHODS@#Sixteen JALS patients were enrolled, including three newly recruited patients between July 2015 and August 2018 from the Second Affiliated Hospital, Zhejiang University School of Medicine. Mutations were screened by whole-exome sequencing. In addition, clinical features such as AAO, onset site and disease duration were extracted and compared between JALS patients carrying FUS and SPTLC1 mutations through a literature review.@*RESULTS@#A novel and de novo SPTLC1 mutation (c.58G>A, p.A20T) was identified in a sporadic patient. Among 16 JALS patients, 7/16 carried FUS mutations and 5/16 carried respective SPTLC1 , SETX , NEFH , DCTN1 , and TARDBP mutations. Compared with FUS mutation patients, those with SPTLC1 mutations had an earlier AAO (7.9 ± 4.6 years vs. 18.1 ± 3.9 years, P  < 0.01), much longer disease duration (512.0 [416.7-607.3] months vs. 33.4 [21.6-45.1] months, P  < 0.01), and no onset of bulbar.@*CONCLUSION@#Our findings expand the genetic and phenotypic spectrum of JALS and help to better understand the genotype-phenotype correlation of JALS.

Two Cases of Acute Myeloid Leukemia with t(16;21)(p11;q22) and TLS/FUS-ERG Fusion Transcripts / 대한진단검사의학회지

Many AML-associated chromosomal abnormalities, such as t(8;21), t(15;17), inv(16), t(9;11), t(9;22) and t(6;9) are well known. The chromosomal aberration of t(16;21)(p11;q22) in AML is rare and it is known to be associated with poor prognosis, young age (median age, 22 yr), and involvement of various subtypes of the French-American-British classification. We report here 2 AML patients with t(16;21)(p11;q22), proved by conventional cytogenetics and/or reverse transcription (RT)-PCR. Erythrophagocytosis by leukemic blasts was observed in both of the cases. One patient was a 24 yr-old male with acute myelomonocytic leukemia. His karyotype was 46,XY,t(16;21)(p11;q22),del(18)(p11.2) and RT-PCR revealed the TLS/FUS-ERG fusion transcripts. Although he received allogeneic peripheral blood stem cell transplantation after the first remission, he died 9 months after the initial diagnosis due to relapse of the disease and graft-versus-host disease. The other patient was a 72 yr-old male with acute myeloid leukemia without maturation. His karyotype was 45,XY,-16,add(21)(q22) and the presence of t(16;21)(p11;q22) was detected by RT-PCR. He was transferred to another hospital with no more follow-up. We suggest that the presence of t(16;21)(p11;q22) and/or TLS/FUS-ERG fusion transcripts has to be considered in cases of AML with erythrophagocytosis.