The enigmatic inflammatory pseudotumours: the current state of our understanding, or misunderstanding.

The inflammatory pseudotumour is a bona fide tumour in the sense of a mass lesion, which is known to present in virtually every anatomic region and organ from the central nervous system to the gastrointestinal tract. A fundamental question about pathogenesis is whether the inflammatory pseudotumour is a pseudo-or true neoplasm. There is evidence to support the argument that some of these fibroinflammatory masses are infection-associated and are often characterized by a proliferation of spindled histiocytes and/or dendritic cells, in contrast to a myofibroblastic proliferation in the other inflammatory pseudotumour, also known as the inflammatory myofibroblastic tumour.