Inflammatory pseudotumor

An inflammatory pseudotumor is a cell proliferation and inflammation involving spindle cells, which may occur in many parts of the body, and is of unknown case.^[1]

According to the WHO classification, three lesional patterns can be observed:

• Inflammatory myofibroblastic tumour, that can be associated with an ALK gene rearrangement
• Plasmocytic pattern ("plasma cell granuloma"), that can be linked to IgG4-related disease
• Fibrous and hyalinizing pattern: Pulmonary hyalinizing granuloma

References

1. Gnepp, Douglas R.; Bishop, Justin A. (5 May 2020). Gnepp's Diagnostic Surgical Pathology of the Head and Neck. Elsevier Health Sciences. p. 984. ISBN 978-0-323-54780-2.