[Successful cord blood transplantation for myelodysplastic syndrome with Behçet disease-like refractory stomatitis and multiple ileocecal ulcerations].

A 12-year-old boy was diagnosed with aplastic anemia. He was followed as an outpatient without medication, and his cytopenia improved after several years. When he was 26 years old, an annual medical checkup revealed leukocytopenia, and at the age of 31 years, he was diagnosed with myelodysplastic syndrome (MDS), refractory cytopenia with multilineage dysplasia. Chromosomal analysis of his bone marrow cells revealed trisomy 8. Ten months after being diagnosed with MDS, he developed refractory stomatitis. Two months later, he experienced abdominal pain and bloody stool, and simple punched-out ulcers similar to intestinal Behçet's disease (BD) were noted in the terminal ileum on colonoscopy. Steroids, mesalazine, and adalimumab were ineffective. Nineteen months after the MDS diagnosis, he underwent cord blood transplantation from an HLA 1-locus mismatched unrelated donor in accordance with a non-myeloablative pretransplant conditioning regimen. The patient's stomatitis and ileocecal ulcers improved following the transplantation. Currently, both MDS and BD-like symptoms are in complete remission at 36 months post transplantation, and the patient continues to take low-dose oral tacrolimus for chronic skin GVHD. Allogeneic hematopoietic stem cell transplantation could become a therapeutic choice for MDS associated with BD, even if refractory intestinal BD symptoms are present.

[Clinical characteristics of vascular adverse events and significance of peripheral artery disease as a risk factor in chronic myeloid leukemia patients treated with nilotinib].

Vascular adverse events (VAEs) in chronic myeloid leukemia (CML) patients treated with nilotinib (NIL) has become a; however, studies on strategies to prevent VAEs remain limited. Therefore, the present study investigated VAEs in 19 CML patients treated with NIL at our hospital. The median age of the patients was 65 years and median follow-up period was 55 months after the initiation of NIL. VAEs occurred in 8 patients (peripheral artery disease (PAD), n=6; cerebral infarction (CI), n=3; coronary artery disease (CAD), n=4). The median elapsed time from the initiation of NIL to VAEs was 42 months. The 4-year cumulative incidence of VAEs was 23.5%. Majority of the patients with VAEs were smokers (P=0.074). All the six patients with PAD were diagnosed on the basis of the ankle-brachial index (ABI<0.9) in the asymptomatic phase; 4 of these patients had other VAEs (CI, n=1; CAD, n=2; CI and CAD, n=1). However, antecedent asymptomatic PAD was diagnosed even before CAD was diagnosed in two patients. Nevertheless, in cardiology, extensive studies have indicated that asymptomatic PAD is a risk factor for the development of cardiovascular events. In conclusion, for the effective management of CML patients treated with NIL, a routine screening with ABI to diagnose asymptomatic PAD may be beneficial in preventing severe VAEs.

[Neurolymphomatosis due to enteropathy-associated T-cell lymphoma clinically diagnosed by FDG-PET/CT and subsequently confirmed by autopsy].

A 59-year-old man who complained of abdominal pain was referred to our hospital. Computed tomography (CT) revealed mesenteric lymph node swelling and intestinal perforation. Histopathological study of the resected ileum and lymph node demonstrated diffuse proliferation of medium-sized atypical lymphocytes. Immunohistochemistry results were positive for cluster of differentiation (CD) 3, CD8, and CD56 cells, negative for CD5 and CD4 cells, and negative for Epstein-Barr virus-encoded RNA-fluorescent in situ hybridization (EBER-FISH). It also revealed the expression of γδ T-cell receptors. On the basis of these findings, enteropathy-associated T-cell lymphoma (EATL) was diagnosed. Although the patient received two courses of cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisone (CHOP) and dexamethasone, etoposide, ifosfamide, and carboplatin (DeVIC) therapy, facial nerve and lower limb paralysis manifested. Magnetic resonance imaging (MRI) and lumbar puncture revealed central nervous system invasion of the EATL. Despite intrathecal chemotherapy and high-dose cytarabine therapy, the patient's neurological symptoms deteriorated. Fluorodeoxyglucose positron emission tomography (FDG-PET) /CT scan showed the accumulation of FDG along both median and sciatic nerves, and he was diagnosed with neurolymphomatosis (NL). He died on day 120 after admission. Autopsy specimens exhibited infiltration of lymphoma cells in the median and sciatic nerves. Although only one case of suspected NL in a patient with type 2 EATL has been previously reported, we clinically diagnosed NL using FDG-PET/CT and confirmed the diagnosis by autopsy. This case is valuable in terms of the pathological diagnosis of NL.

Successful management of intraperitoneal bleeding with platelet apheresis and von Willebrand factor supplementation in a patient with essential thrombocythemia and acquired von Willebrand syndrome.

A 36-year-old woman with essential thrombocythemia (ET) was admitted to our hospital for acute lower abdominal pain. Given no family history of bleeding disorder, she was diagnosed with acquired von Willebrand syndrome. Despite having a medical history of venous thrombosis, she had never been treated for ET because of her preferences. On admission, CT scan revealed massive hemorrhage in the ascending colon with the leakage of a contrast agent. Furthermore, a delayed enhancement of fluid collection in the Douglas fossa followingcontrast CT indicated bloody ascites. Laboratory data revealed elevated platelets (1,569×103/µl) and reduced von Willebrand factor (VWF) :RCo (32%) and VWF:Ag (48%). Platelet apheresis was initiated, combined with the infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea. Three days after admission, her platelet count decreased to 992×103/µl after the second round of platelet apheresis. CT scan revealed no hemorrhage, which implied hemostasis. Because of the absence of symptoms, she was discharged 23 days after admission. These results suggest that platelet apheresis, combined with infusion of VWF-containing concentrates and cytoreductive therapy with hydroxyurea, is an effective approach for the treatment of acquired von Willebrand syndrome characterized by emergent bleeding concomitant with ET.

[Discordant lymphoma of duodenal EBV-positive peripheral T-cell lymphoma not otherwise specified and ileal diffuse large B-cell lymphoma].

A 79-year-old woman was admitted with a 5-kg weight loss and anorexia. Computed tomography showed diffuse lymphadenopathy, and thickening of the duodenal and ileal walls. The patient then underwent biopsy of these sites. Pathological examination revealed duodenal Epstein-Barr virus (EBV)-positive peripheral T cell lymphoma-not otherwise specified (PTCL-NOS) and EBV-negative ileal diffuse large B-cell lymphoma (DLBCL) to be present simultaneously. Combination chemotherapy including rituximab produced a reduction of the duodenal EBV-positive PTCL-NOS lesion, but had no effect on the EBV-negative ileal DLBCL lesion. Thereafter, new lymphadenopathy, high fever, and lactate dehydrogenase (LD) elevation developed, complicated by pneumonia. The patient died due to rapid deterioration of the lymphoma and pneumonia on day 108 after initiation of treatment. EBV-positive PTCL-NOS is reportedly rare and the prognosis is poor. Moreover, EBV-negative ileal DLBCL was diagnosed simultaneously. This case is considered to have had an extremely rare discordant lymphoma, although the exact etiology of its development remains unknown. We speculate that age-related disorders of the immune system and HCV infection may have been associated with the pathogenic mechanism of lymphomagenesis in this case.

Early diagnosis and successful treatment of disseminated toxoplasmosis after cord blood transplantation.

A 66-year-old woman with refractory angioimmunoblastic T-cell lymphoma underwent cord blood transplantation. Prior to transplantation, a serological test for Toxoplasma gondii-specific IgG antibodies was positive. On day 96, she exhibited fever and dry cough. Chest CT showed diffuse centrilobular ground glass opacities in both lungs. The reactivation of T. gondii was identified by the presence of parasite DNA in peripheral blood and bronchoalveolar lavage fluid. Moreover, brain MRI revealed a space occupying lesion in the right occipital lobe. Therefore, disseminated toxoplasmosis was diagnosed. She received pyrimethamine and sulfadiazine from day 99. The lung and brain lesions both showed improvement but the PCR assay for T. gondii DNA in peripheral blood was positive on day 133. On day 146, she developed blurred vision and reduced visual acuity, and a tentative diagnosis of toxoplasmic retinochoroiditis was made based on ophthalmic examination results. As agranulocytosis developed on day 158, we decided to discontinue pyrimethamine and sulfadiazine and the treatment was thus switched to atovaquone. Moreover, we added spiramycin to atovaquone therapy from day 174, and her ocular condition gradually improved. In general, the prognosis of disseminated toxoplasmosis after hematopoietic stem cell transplantation (HSCT) is extremely poor. However, early diagnosis and treatment may contribute to improvement of the fundamentally dismal prognosis of disseminated toxoplasmosis after HSCT.

[Primary graft failure in a patient with refractory acute myeloid leukemia successfully treated with modified 'one-day'-based preparative regimen followed by cord blood transplantation].

A 32-year-old woman with acute myeloid leukemia failed to achieve remission with two courses of induction chemotherapy, and she received cord blood transplantation (CBT) in a non-remission state, using an HLA-matched cord blood (CB) graft after a conditioning regimen of fludarabine (Flu) at 125 mg/m² + melphalan at 140 mg/m² + total body irradiation (TBI) at 4 Gy. Chimerism analysis of the bone marrow (BM) cells performed on day 21 after CBT revealed 99% of these cells to be the recipient type. We diagnosed the patient as having graft failure (GF), and then carried out a second CBT using an HLA-matched male CB graft on day 29 after the first CBT. The conditioning regimen (modified 'one-day'-based regimen) consisted of Flu at 30 mg/m² (3 days) + cyclophosphamide (CY) at 2 g/m² (1 day) + TBI 2 Gy. She achieved neutrophil engraftment on day 18. FISH analysis of BM cells on day 13 showed 96% to be of male origin. She has remained in complete remission for 18 months, to date, since the salvage CBT. This case suggests that salvage CBT following a modified 'one-day'-based regimen may preserve a strong graft versus leukemia effect.

[Chromosomally integrated human herpesvirus-6 requiring differential diagnosis of reactivation after allogeneic hematopoietic stem cell transplantation].

Human herpesvirus-6 (HHV-6) is known to cause critical encephalitis, as a central nervous system infection, in some hematopoietic stem cell transplantation (HSCT) recipients. Chromosomally integrated human herpesvirus-6 (CIHHV-6) persistently shows HHV-6 DNA in blood, but this does not necessarily suggest active infection. The true clinical significance in HSCT is not clear. The prevalence of CIHHV-6 in Japan is reportedly 0.21%. We herein report two HSCTs: from a CIHHV-6-positive donor to a negative recipient and from a negative donor to a positive recipient. In the CIHHV-6-positive donor case, the recipient's plasma, which had been negative for HHV-6 before HSCT, became positive after transplantation and the level then remained high, although the subject was asymptomatic. In the CIHHV-6-positive recipient case, the patient's plasma viral load was high just after transplantation, although the subject was asymptomatic, and the load gradually decreased after engraftment. Antivirals had no effect on the viral load in either case. We should consider CIHHV-6 when the HHV-6 DNA load in blood persists asymptomatically after HSCT, to avoid misdiagnosis of reactivated HHV-6 infection and overuse of antivirals. It is also useful to monitor HHV-6 DNA in blood before HSCT, to distinguish HHV-6 reactivation from CIHHV-6.

[Successful long-term control of recurrent primary central nervous system anaplastic large cell lymphoma after autologous hematopoietic stem cell transplantation with concurrent whole brain and spinal cord radiotherapy].

A 24-year-old woman was hospitalized with seizures in 2002. Magnetic resonance imaging demonstrated an intraspinal mass and inhomogeneous gadolinium enhancement along the cerebrospinal meninges. Cerebrospinal fluid (CSF) cytology showed large atypical cells expressing CD2, cytoplasmic CD3, CD7, CD13 and CD30. The patient was finally diagnosed with primary central nervous system anaplastic large cell lymphoma (ALCL). She completed 5 courses of methotrexate (MTX)/ procarbazine (PCZ)/ vincristine (VCR) (MPV) chemotherapy, followed by 2 courses of high dose cytarabine (AraC) and achieved a complete remission. In 2003, she suffered from headache. CSF analysis showed atypical lymphoid cells expressing CD 30. First CNS relapse was diagnosed. She then underwent autologous peripheral blood stem cell transplantation (auto-PBSCT) after administration of thiotepa, buslfan, and cyclophosphamide. However, second CNS relapse occurred in 2004. She received 5 courses of MPV chemotherapy followed by 36 Gy of craniospinal irradiation. Although there was no recurrence of the CNS disease, a third relapse was detected in the right breast in 2009. Pathological and immunohistochemistry analysis revealed ALK-1 positive ALCL. She was treated with 6 courses of cyclophosphamide/adriamycin/vincristine/predonine (CHOP) chemotherapy and 30.6 Gy of local radiation therapy. She has remained in remission for 6 years, to date, since the last therapy and has an excellent quality of life.

[Therapy-related chronic myelogenous leukemia following RFM therapy in a patient with follicular lymphoma].

Therapy-related myelodysplastic syndrome and acute myelogenous leukemia are increasingly being recognized as treatment complications in patients receiving chemotherapy or radiotherapy for previous neoplasms. However, therapy-related chronic myelogenous leukemia is relatively rare. A 61-year-old woman with a history of radiation therapy for breast cancer had previously, in 2007, received 4 courses of chemotherapy (RFM: rituximab, fludarabine, and mitoxantrone) for follicular lymphoma. In 2010, she was diagnosed with chronic-phase chronic myelogenous leukemia (CML) with Philadelphia chromosome but no other cytogenetic anomalies. Although a complete cytogenetic response (CCyR) was achieved with imatinib therapy, she developed leukocytosis with lymphoblasts and lymphoid crisis was diagnosed in January 2013. G-banded karyotyping showed 45, XX, -7, t, (9;22)(q33;q11.2). Unrelated bone marrow stem cell transplantation was performed after she had achieved a CCyR with dasatinib therapy. Polymerase chain reaction detected no major bcr/abl transcript in her bone marrow 42 days after transplantation. The majority of secondary leukemias resulting from the use of cytotoxic drugs can be divided into two well-defined groups depending on whether the patient has received alkylating agents or topoisomerase II inhibitors. However, concerns regarding the leukemogenic potential of fludarabine-based chemotherapy are growing. The potential risk of therapy-related leukemias including CML needs to be considered following fludarabine-based chemotherapy.

Congenital dysfibrinogenemia coincidentally diagnosed at the onset of chronic myelogenous leukemia.

A 34-year-old man was referred to our hospital for leukocytosis and fundal hemorrhage. Peripheral blood and coagulation tests showed increases in cells at all stages of the neutrophilic series and a low level of fibrinogen (Fbg). Chronic myelogenous leukemia (CML) was diagnosed, and nilotinib was administered. During the clinical course of CML treatment, plasma Fbg levels continued to be low, but the patient showed neither hemorrhagic nor thrombotic complications. Fbg analysis showed normal antigen levels and low activity levels, which indicated dysfibrinogenemia. Genetic analysis revealed a heterozygous gene mutation (γ308AAT→AAG), a mutation which was also found in the patient's mother. Asymptomatic patients with dysfibrinogenemia have a low risk of hemorrhage in daily life and do not require treatment. However, in those undergoing major surgery or in serious accidents, replacement therapy may be required. When the cause of low Fbg levels is unknown, dysfibrinogenemia or fibrinogen deficiency should be considered. Even asymptomatic patients may benefit from more detailed immunologic and genetic analyses.

[Fatal bone marrow necrosis and fat embolism following sepsis in a patient with acute lymphoblastic leukemia after consolidation chemotherapy].

We report a 58-year-old Japanese man with acute lymphoblastic leukemia. On the seventh day of his second course of consolidation therapy, he developed herpes zoster, and on the 17th day, he developed a high fever, dyspnea, and lapsed into a coma. Streptococcus constellatus was isolated from blood culture. Despite intensive therapy, multiple organ failure progressed rapidly, and he died on the 19th day. Pathological examination of autopsy specimens revealed bone marrow necrosis and fat embolism in multiple organs. In this patient, sepsis led to bone marrow necrosis and, subsequently, to fat embolism.

[Successful treatment with low-dose etoposide for hemophagocytic syndrome following reduced-intensity conditioning for cord blood transplantation in a patient with acute myelgenous leukemia].

A 56-year-old man was diagnosed with acute myeloid leukemia with myelodysplasia-related changes. Chromosomal analysis showed a complex karyotype. Complete remission could not be achieved even after several induction chemotherapy regimens, and the patient suffered from invasive pulmonary aspergillosis. He was transferred to our hospital and underwent reduced-intensity conditioning cord blood transplantation (RIC-CBT) in a non-remission state. The conditioning regimen involved fludarabine 125 mg/m2 combined with melphalan 140 mg/m2 and total body irradiation (4 Gy). GVHD prophylaxis was tacrolimus alone at relatively low concentrations (app. 5 ng/ml). On days 6 and 9 after CBT, he experienced a pre-engraftment immune reaction and hemophagocytic syndrome (HPS). We started steroid pulse therapy, but this failed to resolve the symptoms. We then administered low-dose etoposide (50 mg/m2). The symptoms gradually resolved after three administrations of etoposide and engraftment was achieved on day 35. Satisfactory hematological recovery was noted on day 300 after CBT and the patient has maintained complete remission to date. HPS is one of the most serious complications following CBT and often results in engraftment failure. This case suggests that repeated administration of etoposide may safely and effectively overcome this serious complication in some cases.

[Long-term remission of Langerhans cell sarcoma by AIM regimen combined with involved-field irradiation].

A 67-year-old woman presented with a right inguinal mass in May 2006. CT scan showed lymph node involvement from the right inguinal to the common iliac and (18)F-FDG-PET revealed uptake in those areas. Biopsy results indicated Langerhans cell sarcoma (LCS). Interestingly, tumor cells expressed a high MIB1 index of 30%. We administered doxorubicin, ifosfamide, and mesna (AIM) chemotherapy, which were reported to effectively treat soft tissue sarcoma. After 5 courses of AIM therapy and involved-field radiation for residual diseases and a relapsed lesion on her right cervical node, she has remained in complete remission for more than 4 years. LCS is an intractable malignant disease and the optimal therapeutic strategy remains unclear. The AIM regimen combined with radiation therapy may be an effective treatment option for this disease.

Rapid Improvement in Jaundice Using Transdermal Isosorbide Tape as a Nitric Oxide Donor in Two Adult Patients with Transplantation-associated Microangiopathy Related to Graft-versus-host Disease.

Two adult patients with acute leukemia developed transplantation-associated microangiopathy (TAM) related to graft-versus-host disease (GVHD). Both patients were resistant to standard therapy for TAM and GVHD, which led to markedly elevated serum total bilirubin levels of 47.5 and 10.6 mg/dL, respectively. Transdermal isosorbide tape as a nitric oxide donor was applied to Patients 1 and 2 on post-transplantation days 60 and 66, respectively, which rapidly improved their jaundice after 1 day. This is the first report to describe the efficacy of transdermal isosorbide tape for adult patients with jaundice associated with TAM related to GVHD.

Epstein-Barr virus-associated lymphoproliferative disorder developed after anti-thymocyte globulin therapy in a patient with bone marrow failure associated with T-cell large granular lymphocytic leukemia.

A 75-year-old man was referred to our hospital for marked neutropenia and anemia. Bone marrow examination showed marked hypoplasia with 45.2% infiltration of CD3+, CD8+, CD16+ and CD57+ granular lymphocytes. Monoclonal rearrangement of T-cell receptor gene was observed by Southern blot analysis. Taking these findings together, T-cell large granular lymphocyte leukemia (T-LGL) with bone marrow failure was diagnosed. The patient was treated with immunosuppressive therapy (IST) consisting of anti-thymocyte globulin and cyclosporine. Although pancytopenia subsided after IST, fever and lymphoadenopathy developed on the 29th day after IST. The presence of Epstein-Barr virus (EBV) in peripheral blood was confirmed using real time PCR (3.5×10(6) copies/10(6)WBC). Although gancyclovir and foscarnet were started, rapidly progressive hepatomegaly and liver dysfunction developed. The patient died on the 42nd day after IST. Autopsy specimen showed infiltration of abnormal CD20-positive large lymphocytes in the portal area of the liver, white pulp of the spleen, kidneys and adrenal glands. The nuclear EBV-encoded RNA (EBER) stain was positive in the abnormal large lymphocytes and a diagnosis of EBV-associated B-cell lymphoproliferative disorder (EBV-LPD) was made. We should regard the potential risk of EBV-LPD after immunosuppressive therapy for patients with bone marrow failure caused by T-LGL.

Central nervous system involvement in intravascular large B-cell lymphoma: a retrospective analysis of 109 patients.

Intravascular large B-cell lymphoma (IVLBCL) is a rare disease entity with a high incidence of central nervous system (CNS) involvement at diagnosis. To evaluate CNS involvement, particularly recurrence including progression on therapy and relapse of IVLBCL, we retrospectively analyzed 109 patients with IVLBCL receiving chemotherapies with or without rituximab. In 82 patients (75%) without CNS involvement at initial diagnosis, risk of CNS recurrence at 3 years was 25% with a median follow-up in survivors of 39 months (range, 2-158 months). In 27 patients (25%) with CNS involvement at initial diagnosis, risk of CNS recurrence at 1 year was 25% with a median follow-up in survivors of 18 months (range, 10-77 months). Duration from diagnosis to CNS recurrence tended to be short in patients with CNS involvement at diagnosis. No significant difference in risk of CNS recurrence was found between patients receiving chemotherapies with or without rituximab. On multivariate analysis skin involvement at initial diagnosis was identified as a predictive factor for CNS recurrence in patients without CNS involvement at diagnosis (hazard ratio, 5.27; 95% confidence interval, 1.59-17.4; P = 0.007). Survival rate after CNS recurrence at 2 years was 12% in patients without CNS involvement at diagnosis. Central nervous system recurrence is a serious complication in IVLBCL patients and optimal strategies for CNS involvement should be established to obtain further improvements to clinical outcomes in the rituximab era.

[High-titer idiopathic acquired factor V inhibitor patient showing decreased activities of multiple coagulation factors].

A 72-year-old male presented with oral bleeding resulting from acquired factor V (FV) inhibitor. We observed abnormalities in prothrombin time (PT) (8%) and activated partial thromboplastin time (APTT) (>200 seconds). FV activity was less than 3%, and a mixing test did not correlate with PT. FV inhibitor assay demonstrated 240 Bethesda units/ml. The patient also showed markedly decreased activity of Factors II (13%) and X (14%). Oral bleeding disappeared and coagulation abnormalities improved with prednisolone therapy. High titer FV inhibitor might affect coagulation assays even in a patient with normal factor activity.

[Asymmetric peripheral neuropathy following reduced-intensity cord blood transplantation].

A 57-year-old male patient in the first remission of acute erythroid leukemia underwent reduced-intensity umbilical cord blood transplantation. He developed grade III acute graft-versus-host disease (GVHD) on day 29. Although the acute GVHD was resolved with tacrolimus and steroid therapy, weakness developed in the left upper extremity on day 59. Neurological examination demonstrated asymmetric muscular weakness of the extremities with the proximal part of the left upper extremity being markedly affected. Neurophysiological studies suggested that this was due to immune-mediated demyelinating neuropathy. Intravenous immunoglobulin (IVIG) therapy was administered at a dose of 0.4 g/kg/day for 5 days and worsening of clinical symptoms ceased. While the patient developed diarrhea and chronic GVHD of the skin and cytomegalovirus (CMV) antigenemia was repeatedly positive, neurological exacerbation was stabilized. Neurological symptoms did not immediately improve after the second and third dose of IVIG. Approximately 50 days after the third dose of IVIG, neurological symptoms improved with the gradual resolution of diarrhea and CMV reactivation. Although the pathophysiology of polyneuropathies after allo-SCT is not well understood, some reports suggest an association with GVHD or alloreactive T cell expansion following antecedent infection. This case provides valuable information regarding the pathophysiology of peripheral neuropathy following allo-SCT.

Analysis of five cases of human herpesvirus-6 myelitis among 121 cord blood transplantations.

Reports of myelitis associated with human herpesvirus-6 (HHV-6) following allogeneic transplantation are rare. Of 121 cases of cord blood transplantation (CBT) performed at Nagano Red Cross Hospital, five cases (4.1%) of HHV-6 myelitis developed at around the time of engraftment. The major symptom identified in all five patients was superficial pain or pruritus linked to segmental levels of the spinal cord. Other identified symptoms were fever or low-grade fever in all five patients, autonomic nerve disorder in four patients, bladder and rectal disturbance in two patients, and extrapyramidal disorder in two patients. These symptoms were experienced primarily 16-39 days after CBT. HHV-6 PCR tests were all positive for cerebrospinal fluid and for plasma. Of the four cases tested by magnetic resonance imaging (MRI), three showed spinal cord abnormality. Antiviral therapy using foscarnet or ganciclovir was effective in every case. Although one case treated from 12 days after onset experienced long-term pain resembling postherpetic neuralgia, symptoms in the four cases were completely relieved after antiviral therapy. In summary, the major symptoms of HHV-6 myelitis were superficial pain linked to segmental levels of the spinal cord. Prognosis may be improved by early initiation of antiviral therapy.