Case report demonstrates ALK-positive histiocytosis diagnosed in an infant, revealing a novel PTRH2::ALK fusion gene, implying critical diagnostic insights.
Key Points
This case report aims to present a rare instance of ALK-positive histiocytosis in an infant that was misdiagnosed as a liver abscess and highlight a novel fusion gene.
Histopathological examination of biopsy specimens from skin rashes
Fluorescence in situ hybridization for ALK rearrangement
Next-generation sequencing to identify the PTRH2::ALK fusion.
Histopathological findings included a proliferation of histiocytes, multinucleated giant cells, and positive immunohistochemical markers for ALK and S100.
Next-generation sequencing identified a novel PTRH2::ALK fusion in the patient.
PET-CT revealed widespread lesions consistent with ALK-positive histiocytosis.