Skull Lesions in Langerhans-Cell Histiocytosis Usually Resolve Without Treatment

By Gene Emery

June 30, 2022

(Reuters Health) - Call it a case of where Voltaire was correct to say, "The art of medicine consists of amusing the patient while nature cures the disease."

A new prospective study of children and adolescents with a single skull lesion caused by Langerhans-cell histiocytosis suggests that watchful waiting is an effective strategy and the surgical resection or curettage sometimes recommended is unnecessary.

In a letter published in Thursday's New England Journal of Medicine, a team led by Dr. Paul Steinbok of the University of British Columbia reports that among 17 patients assigned to an observation-only group, the scalp lesions decreased in size or disappeared after two months.

In 15 of the 17, there was complete resolution of the lesion within a year.

"After a median of 6.4 years (range, 2.7 to 9.8), no recurrences or other complications had been identified in these 17 patients," they said.

Eleven other patients were placed in an active intervention group where 2 got chemotherapy, 1 was treated with intralesional glucocorticoids and 10 received craniotomy, of whom 6 also underwent cranioplasty.

"The current multicenter international study is a landmark study that answers this question once and for all," coauthor Dr. David Sandberg of the McGovern Medical School in Houston, Texas, told Reuters Health in an email. "Its publication in the NEJM will help spread the word to our pediatric neurosurgery and neuro-oncology colleagues that surgery is not necessary for these lesions."

Currently, "such surgical treatment is considered by almost all oncologists and surgeons to be the most appropriate management, and this is what is written in even the most recent textbooks," first author Dr. Paul Steinbok of the University of British Columbia, in Vancouver, said in a separate email.

The origin of the study dates to 1998, when Dr. Steinbok had a patient with a scalp mass, but it took 3 weeks to schedule the surgery.

"When I assessed the child before going into the operating room to do the surgery, I could not find any lump on the scalp. The mass had disappeared. The surgery was canceled," he recalled.

Soon after, he was sent another patient with a lesion at the back of the head, where surgery would be dangerous. That lump went away by itself as well. By 2003 he had collected four cases where the lesions had resolved without intervention.

But it took years to arrange a prospective study, and it was only done after Dr. Sandberg decided to adopt a similar approach and also reported success with not doing surgery.

Children from eight centers were enrolled in the new international study.

The largest lesion measured in the observation-only group was 40 mm across. Five were frontal, one was frontoparietal, one was frontotemporal, three were occipital, three were parietal, three were parieto-occipital and one was temporal.

There was a plan for rescue therapy - using any combination of surgery, chemotherapy and glucocorticoids - if the lesion was growing rapidly, if it was still getting bigger two months after enrollment, if it was not smaller after three months, or if it was causing unacceptable pain.

That strategy was designed to treat a lesion that might be more dangerous, such as a tumor.

In no case was rescue therapy needed.

"With observation only, these lesions get smaller and disappear. Furthermore, there is usually a defect in the skull bone underlying the mass on the scalp and with observation only the bony defect fills in completely or nearly completely," said Dr. Steinbok, a professor emeritus in UBC's department of surgery.

"The result is better than is achieved with surgical resection, which leaves a scar on the scalp and also often requires a cranioplasty to fill in the skull defect caused by the lesion itself and the bony resection by the surgeon," he said.

"Parents with a child diagnosed with a solitary LCH lesion of the cranial vault should accept that a recommendation by their doctor to observe only, without biopsy, is probably the most appropriate recommendation," he said, and "they should be prepared to question the need for surgery if that is the recommendation of the initial treating physician or, as sometimes occurs, the recommendation obtained as a second opinion."

SOURCE: The New England Journal of Medicine, online June 29, 2022.