Rectal arterio-venous malformation (AVM) with bleeding of an internal hemorrhoid.

A 38-year-old male with no past history of illnesses visited the out-patient clinic of Nerima Hikarigaoka Hospital complaining of dizziness and persistent anal bleeding. There was a significant anemia on a blood test and colonoscopy showed a thrombus in a markedly swollen internal hemorrhoid. Contrast-enhanced computed tomography (CT) showed a poorly demarcated area with early face enhancement on the right side of the rectum and anal canal. Based on these findings, an arterio-venous malformation (AVM) of the rectum was suspected. Abdominal angiography showed abnormal vessels receiving a blood supply from the bilateral superior rectal arteries. We suspected that the AVM in the rectum was the cause of the hemorrhage from the internal hemorrhoid, and therefore performed embolization of the AVM. Thereafter, the hemorrhage from the internal hemorrhoid stopped completely and the anemia improved to the normal level, without the need for treatment for the internal hemorrhoid. Colonoscopy performed 6 months after embolization showed shrinkage of the internal hemorrhoid. To the best of our knowledge, there are no reports stating a relationship between rectal AVM and internal hemorrhoids. However, we consider that contrast-enhanced CT can be used to detect vessel abnormalities related to severe bleeding of the internal hermorrhoids in patients with internal hemorrhoids and severe anemia.

[Rupture of an internal carotid-posterior communicating artery aneurysm formerly presented with transient pupil-sparing oculomotor nerve palsy in an extremely elderly patient].

We recently encountered experienced a rare case of transient pupil-sparing oculomotor nerve palsy(PSONP)caused by an aneurysm at the junction of the internal carotid-and posterior communicating arteries(IC/PC AN)in an 87-year-old, non-diabetic woman. She initially presented with diplopia 4 years previously, and was diagnosed, based on incomplete right oculomotor paresis without pupil involvement(PSONP), as external ophthalmoplegia. MR-angiography revealed a long protrusion of the IC/PC AN with posterior-inferior projection, for which she chose to receive conservative management. Thirty nine months later, she presented with another transient PSONP. CT angiography(CTA)showed that the aneurysm was enlarged in the posterior-inferior direction. Two days after this last CTA imaging, the aneurysm ruptured with upward enlargement of the bleb. Despite complete external ophthalmoplegia and ptosis, her pupil involvement was still minimal and transient. By reviewing reported cases and our own case, we found that a narrow and long aneurysm body and posterior-inferior projection are characteristic for the IC/PC AN that causes PSONP, implying a possible mechanism for PSONP by upward compression of the oculomotor nerve. Though rare in its incidence, IC/PC AN could present with PSONP prior to their rupture. Therefore, immediate imaging evaluation in patients presenting with PSONP is essential to prevent devastating rupture events.

Epstein-Barr virus and methotrexate-related CNS lymphoma in a patient with rheumatoid arthritis.

Patients with rheumatoid arthritis (RA), especially those treated with methotrexate (MTX), might have an increased risk of lymphoproliferative disorders that are associated with Epstein-Barr virus (EBV). We describe a case of EBV-associated central nervous system (CNS) lymphoma (diffuse large B-cell lymphoma) in a patient with RA on a short course of MTX treatment. The neoplastic cells express the B-cell surface markers (CD20, Pax-5 and CD30), and EBV-encoded RNA was demonstrated by in situ hybridization. The patient's lymphoma did not recur for the 8-year follow-up period after the tumor resection and cessation of MTX. MTX may promote EBV-positive CNS lymphoma in RA patient due to its immunosuppressive properties as well as reactivating latent EBV infection.