RT Journal Article
SR Electronic
T1 Indolent Multinodular Synovial Sarcoma of Peripheral Nerves Mimicking Schwannoma: A Case Report and Literature Review
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 5729
OP 5736
DO 10.21873/anticanres.16779
VO 43
IS 12
A1 KAWASAKI, TOMONORI
A1 ICHIKAWA, JIRO
A1 IMADA, HIROKI
A1 KANNO, SATOSHI
A1 ONOHARA, KOJIRO
A1 YAZAWA, YASUO
A1 TATSUNO, RIKITO
A1 JYUBASHI, TAKAHIRO
A1 TORIGOE, TOMOAKI
YR 2023
UL http://ar.iiarjournals.org/content/43/12/5729.abstract
AB Background/Aim: Most cases of synovial sarcoma (SS) are aggressive and large-sized; only few show indolent behavior, having a small size. Nerves are rare sites of SS occurrence. An atypical case of SS can lead to its misdiagnosis as a benign tumor and delay its treatment. Case Report: Here, we report a case of primary SS of indolent multinodular synovial sarcoma of peripheral nerves. Considering the clinical and imaging findings at the first visit, we suspected a benign tumor and continued careful follow-up. Three years later, marginal resection was performed and SS was suspected. We then performed an additional wide resection using a free flap. Histopathologically, the proximal tumor showed a diffuse proliferation of spindle cells without pleomorphism, whereas the distal tumor showed a similar histology with more hypercellularity. Additional wide-resection specimens showed remnant tumors derived from the peripheral nerve. Immunohistochemistry (IHC) showed positive staining for SS18:SSX and SSX in both tumors and fluorescence in situ hybridization showed positive staining for the SS18 split in both tumors. Finally, SS of the peripheral nerve was diagnosed. Owing to FNCLCC grade 2 tumor and tumor size, adjuvant chemotherapy was not performed. Conclusion: In cases of SS or other sarcomas with atypical clinical courses, with imaging findings mimicking benign tumors, we recommend marginal resection along with pathological examination for correct diagnosis.