FDG PET/CT in ALK-positive Histiocytosis of the Nasal Cavity in a Pediatric Patient

Anaplastic lymphoma kinase (ALK)-positive histiocytosis is a rare newly recognized subtype of histiocytic neoplasms. The disease can involve multiple systems or single system. We present FDG PET/CT findings in a pediatric patient with ALK-positive histiocytosis isolated to the left nasal cavity. The nasal cavity tumor invaded the nasal septum, left nasal bone, and left ethmoid sinus and showed intense FDG activity with an SUV max of 9.9.