Work

Delayed Neurologic Response to Dabrafenib and Trametinib in the Case of Mixed Histiocytosis (LCH/ECD): Case Report and Literature Review

Year: 2026

Type: article

Abstract: Background and Clinical Significance: Histiocytosis encompasses Langerhans cell histiocytosis (LCH) and non-LCH, such as Erdheim–Chester disease (ECD). ECD or a mixed type of histiocytosis (LCH/ECD) may initially involve the central nervous system (CNS), resulting in a delayed diagnosis. More recently, dabrafenib and trametinib (Dab/Tra regimen) have become available in its treatment. Case Presentation: A 46-year-old woman with CNS involvement of mixed histiocytosis (BRAF V600E-positive LCH/ECD) was treated with combination therapy using a Dab/Tra regimen. At initial presentation, she exhibited central diabetes insipidus, dysarthria, and gait disturbance with mild spasticity and ataxia, requiring walking assistance even for short distances. The interval from the onset of central neurological symptoms to diagnosis of mixed histiocytosis was 4 years. The introduction of targeted therapy was 2 years later. After seven months of Dab/Tra therapy, partial neurological improvement was observed, as reflected by a decrease in the SARA score from 21/40 to 13/40 and the ICARS score from 33/100 to 28/100. However, further neurological recovery remained significantly delayed. Conclusions: We suspect that the limited improvement may be attributable to the delayed initiation of targeted therapy, in contrast to the more rapid and pronounced responses reported in cases where treatment was started earlier.

Source: Reports — Medical Cases Images and Videos

DOI: 10.3390/reports9010018

Authors: Shinsaku Imashuku, Miyako Kobayashi, Takashi Miyoshi, Naoyuki Anzai

Institution: Uji-Tokushukai Medical Center

Language: English

Topic: Histiocytic Disorders and Treatments

Subfield: Physiology

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,689