Study Reviews Recent Pediatric Skin Biopsy Trends at a Tertiary Care Center

Among more than 1,000 skin biopsies performed over the last 6 years by pediatric dermatologists at the University of California, San Francisco (UCSF), the three most common biopsy results were compound nevus, pyogenic granuloma, and spongiotic dermatitis.

In addition, fewer biopsies were performed in the first 3 years of the global COVID-19 pandemic than in the previous 3 years.

These findings from a retrospective analysis were presented during a poster session at the annual meeting of the Society for Pediatric Dermatology. The analysis set out to evaluate which patients required biopsy, which skin conditions were sampled, and if practice patterns changed following the start of the COVID-19 pandemic.

"The work is important because very few pediatric patients, relative to adult patients seen in dermatology clinics, have a biopsy done," Kelly M. Cordoro, MD, one of the study authors, told this news organization.

"Approximately 1%-4% of pediatric patients visiting a dermatology clinic will have a biopsy done as compared to 30%-50% of adult patients. Understanding what is being biopsied in children sheds light on the medical decision-making required to decide when a biopsy is necessary," said Dr. Cordoro, chief of pediatric dermatology at UCSF.

For the study, the researchers retrospectively reviewed 1,196 biopsy specimens from 1,080 unique patients that were performed by pediatric dermatologists at UCSF from 2017 to 2022. Half of the patients were female, their mean age was 11.5 years, and they ranged in age from 1 day to 61 years. Nearly half of biopsies (47%) were performed in patients aged 12-18 years and one-quarter (25.6%) were performed in those aged 6-11 years. In the remaining biopsies, 6.6% came from patients younger than 1 year, 5.8% of those aged 1-2 years, 7.3% from those aged 3-5 years, and 3.9% each in those aged 19-21 years and in those older than 21 years.

The five most common biopsy results were compound nevus (99 biopsies), pyogenic granuloma (96), spongiotic dermatitis (57), intradermal nevus (53), and pilomatricoma (40).

The researchers identified 30 malignant diagnoses in 28 unique patients, most commonly mycosis fungoides (in 16 patients with a median age of 12.5 years), basal cell carcinoma (in 5 patients with a median age of 9 years), and dermatofibrosarcoma protuberans (in 4 patients with a median age of 2 years).

There was no significant sex-based difference in the number of biopsies performed at a given age (P = .47), but Dr. Cordoro and colleagues noted a statistically significant decrease in the number of biopsies during the pandemic compared with the 3 years prior to the pandemic (P = .04).

"There was a slight uptick in 2022, although it remains to be seen whether this trend will continue," they wrote in their abstract. "While the most common diagnoses in the years leading up to – versus following the start of the pandemic – were similar, there was one clear outlier. The histopathologic diagnosis of pernio spiked in 2020, reflecting the 'COVID toes' phenomenon".

In an interview, Dr. Cordoro said that growths and rashes in children of all ages can, and should, be biopsied, but special considerations are necessary depending on the patient's age and context.

"Our data showed that neoplastic conditions were biopsied more often than inflammatory conditions, with an emphasis on lesions that required removal (such as pyogenic granuloma), raised concerns for atypia (nevi), or had implications for systemic management (such as Langerhans cell histiocytosis and graft-versus-host disease). Importantly, cutaneous malignancies in children are rare but do occur, and a high index of suspicion is required when approaching any child with a complex neoplasm or rash."

Dr. Cordoro characterized the medical decision making and rationale for biopsying skin lesions and rashes in children as "a complex process that involves weighing the risks of the biopsy itself against the benefit of the information it will provide; shared decision-making with the caregivers, the patient (if age-appropriate), and other members of the health care team; age of the child and clinical context; and whether the biopsy can be done at the bedside or requires sedation."

Based on the study results, Dr. Cordoro said, the rationale to proceed with a biopsy boils down to three main goals: To make or confirm a diagnosis, to make decisions about management, and/or the biopsy itself is therapeutic.

UCSF dermatopathology fellow Suzanne W. Birmingham, MD, performed the study in collaboration with Dr. Cordoro and UCSF dermatopathologist Thaddeus W. Mully, MD. Additional analyses of this data set are in progress. The researchers reported having no relevant financial disclosures.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.