Anaplasic lymphoma kinase positive inflammatory myofibroblastic tumour with renal pelvic calculus: a case report

Inflammatory myofibroblastic tumour is a distinctive mesenchymal neoplasm, composed of a variable admixture of myofibroblastic spindle-shaped and inflammatory cells which were originally described in the lung, as a nonneoplastic lesion and designated as an inflammatory pseudotumour. The lack of certainty of the IMTs pathogenesis is reflected in the large number of terms which have been attributed to this lesion. Recent genetic and molecular studies of IMTs have showed chromosomal abnormalities of 2p23 resulting in a rearrangement of the anaplasic lymphoma kinase gene and have also provided evidence for a monoclonal, noeplastic origin for IMT.Occurrence of IMT in the kidney is very rare, and to our knowledge, only 30 such cases have been described in the literature.This report describes an original case of an ALK positive IMT of the kidney associated with renal pelvic calculus which we believe has never been reported. The differential diagnosis of IMTs will also be discussed.