NTRK rearranged spindle cell neoplasm of the uterine cervix: a rare case report and literature review.

BACKGROUND: Neurotrophic tyrosine receptor kinase (NTRK) rearranged spindle cell neoplasm is an emerging group of molecularly defined rare soft tissue tumors, often presenting with a monotonous spindle cell morphology, infiltrative growth, and co-expression of S-100 and CD34 proteins by immunohistochemistry (IHC). Accurate diagnosis necessitates the combination of morphology, immunohistochemistry, and molecular test results, with next-generation sequencing (NGS) as the gold standard. We present a rare case of NTRK rearranged spindle cell neoplasm of the uterine cervix and review the literature to highlight the current understanding of the diagnosis and treatment of this rare disease.

CASE PRESENTATION: A 49-year-old perimenopausal woman presented with menorrhagia for more than a month. A biopsy of the cervix revealed a cervical spindle cell neoplasm with a tendency to be an isolated fibrous tumor. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed and the surgical pathology suggested NTRK rearranged spindle cell neoplasm, while NGS confirmed TFG-NTRK3 fusion gene. Postoperatively, the patient refused larotrectinib maintenance therapy for economic reasons and had no sign of recurrence or metastasis at 31 months of follow-up.

CONCLUSION: We presented the first case of cervical spindle cell neoplasm with TFG-NTRK3 gene rearrangement and retrieved 22 cases of NTRK rearranged spindle cell neoplasm of the uterine cervix from literature. The most prevalent type of gene fusion was TPM3-NTRK1, and almost all cases demonstrated S-100 and CD34 positivity by IHC. Surgery remains the initial treatment of choice and tyrosine receptor kinase (TRK) inhibitors may serve as a promising target therapy for patients with recurred or metastatic disease.