Reactive Granulomatous Dermatitis

Interstitial Granulomatous Dermatitis in a Patient with Prostate Cancer

“…In addition, the histiocyte infiltrate is focal. However, in IGD, the histiocyte infiltrate tends to be more diffuse with deeper dermis and mucin deposition is minimal or absent23. In our patient, Alcian blue stain at pH 2.5 revealed no mucin deposition.…”

“…Clinically, it is characterized by erythematous to violaceous patches or plaques symmetrically located on the upper trunk and proximal limbs. Linear subcutaneous cords or bands known as the “rope sign” was considered pathognomic initially234. However, this finding has only been reported in less than 10% of cases.…”

“…Histopathological findings of IGD is characterized by interstitial arrangement of CD 68+ epithelioid histiocytes scattered throughout the dermis in varying densities, frequently around the foci of degenerated collagen23456. Rarely, eosinophils and neutrophils can be found in IGD.…”

“…Rarely, eosinophils and neutrophils can be found in IGD. Vasculitis is generally absent2345. It might be difficult to differentiate interstitial granuloma annulare (IGA) from IGD clinically and histologically.…”

“…Histological feature of IGD is interstitial infiltrate of histiocytes in the reticular dermis. IGD is associated with various systemic conditions, such as arthritis, autoimmune disease, connective tissue disease, and internal malignancy23456. We describe a rare case of IGD associated with prostate cancer.…”