Necrotizing and giant cell granulomatous phlebitis of caecum and ascending colon.

A distinctive form of necrotizing and granulomatous phlebitis of a segment of large intestine is described in a previously healthy 36-year-old woman who presented with sudden severe abdominal pain and diarrhoea. At operation the caecum and ascending colon were oedematous and inflamed and right hemicolectomy was performed. Microscopically there was striking involvement of veins in all coats of the bowel ranging from recent fibrinoid necrosis of the whole vessel wall in the case of the caecum, to more chronic giant cell granulomas in parts of the vessel wall with partial or complete occlusion of the lumen in ascending colon. Arteries and lymphatics were entirely spared of these changes. The aitiology of this condition has not been elucidated but the histological appearances and site of involvement suggest an immunological reaction to material absorbed from the bowel. No evidence of food or other allergies or of infection has been obtained. The patient remains symptom free after 18 months. This form of phlebitis does not appear to have been previously described.