Development of a calcifying fibrous pseudotumour within a lesion of Castleman disease, hyaline-vascular subtype

A nine year old boy with localised Castleman disease of the hyaline-vascula r subtype developed a calcifying fibrous pseudotumour. This pathological as sociation does not appear to have been described before. In this case, the development of this very unusual soft tissue tumour-like process was though t to be related to a previous fine needle aspiration biopsy, which was perf ormed because of lymphadenopathy localised to the right inguinal area. This case provides further evidence of the reactive nature of calcifying fibrou s pseudotumour and also broadens the pathological spectrum of the stromal c ell proliferation that occasionally supervenes within lesions of Castleman disease, hyaline-vascular type.