First described by Dr. Benjamin Castleman in 1956, Castleman disease is an uncommon disease of an etiology that is not yet thoroughly known. Three distinct histological subtypes have already been described: hyaline-vascular-, plasma cell-, and human herpes virus 8-associated variant, clinically distinguished in multi or unicentric types. Castleman disease is occasionally diagnosed in children, but more often in young adults, with no gender predominance. The symptoms are rather heterogeneous, varying from an asymptomatic mass in the unicentric Castleman disease type, to life-threatening systemic inflammatory state with systemic symptoms in the multicentric Castleman disease type. The authors report a case of a 15-year-old boy who sought medical attention due to a cervical tumor mass, without systemic symptoms. Pathology exam of the excised mass diagnosed a very typical example of the hyaline-vascular unicentric type of Castleman disease.