Musculoskeletal small biopsies from small patients: current status in 2 academic hospitals

Pediatric bone and soft tissue (BST) lesions typically undergo biopsy prior to treatment, which commonly involves core needle biopsy (CNB) and/or fine-needle aspiration biopsy (FNAB). This study looks at the utility of small biopsies in the current diagnosis of pediatric BST lesions from 2 institutions. A retrospective search of BST small biopsies obtained during a 2-year time period (2018-2019) at 2 academic institutions was performed to look at clinicopathologic features, biopsy diagnoses, and correlation with follow-up. A total of 96 pediatric patients (average age 11.2 years, range: 10 months-19 years) with BST lesions underwent a small biopsy, which represents 5% of the total BST lesions biopsied. The results show that the majority of lesions were benign (65%), and diagnosed by CNB alone (73%); a combination of FNAB and CNB (16%), and FNAB alone (11%), were less frequent. The CNB was effective in making a definitive diagnosis in 93% of cases and overall small biopsy was effective in 91% of the cases. Cases with definitive diagnoses on small biopsy were more likely to have concurrent CNB or characteristic ancillary studies performed. Although pediatric BST lesions constitute only 5% of all BST lesions biopsied, minimally invasive small biopsies with cytologic evaluation for triage and appropriate ancillary study utilization can help render specific diagnoses that help to determine the appropriate treatment for young patients with BST lesions. The current diagnostic approach frequently involves CNB with intraprocedural evaluation or concurrent FNAB, with fewer biopsied by FNAB alone.