Pulmonary Hyalinizing Granuloma

The central portions of hyalinizing granuloma usually tend to be hypocellular (right one-third of the image) as compared to their periphery. The relative hypocellularity is due to fewer fibroblasts and inflammatory cells in the center of the lesion. In difficult cases of hyalinizing granuloma, negative Congo red staining will exclude nodular amyloidosis as a diagnostic possibility.