[Clinicopathological and molecular genetic features of lipofibromatosis-like neural tumor]

Objective: To investigate the clinicopathological and molecular genetic features of lipofibromatosis-like neural tumor(LPF-NT). Methods: Three cases of LPF-NT in Children's Hospital of Fudan University from December 2018 to December 2019 were analyzed for their diagnosis and differential diagnosis. Results: One case was male and two cases were females, all of them aged under 1 years old. The clinical manifestation of LPF-NT was a local infiltrative growth mass in subcutaneous tissue. There were no specific radiologic features. Histologically, dense fascicles or compact sheets of spindle cells showed infiltration into subcutaneous adipose tissue. Spindle cells displayed a moderate degree of nuclear atypia with mitotic activity cells.Immunohistochemical study showed the tumor cells diffusely expressed S-100 protein, CD34, NTRKI, and pan-TRK. Fluorescence in situ hybridization detected rearrangement of NTRK1 gene in all 3 cases tested. Conclusions: LPF-NT is a newly named soft tissue tumor. Histological morphology, immunohistochemistry and molecular detection are helpful for the diagnosis and differential diagnosis of the disease.