A 64-year-old female underwent haploidentical allogeneic HSCT for diagnosis of acute myeloid leukemia secondary to myelodysplastic syndrome in September 2016. A haploidentical son, 41 years old, 0 Rh positive, EBV, CMV, and toxoplasma IgG positive, was selected as the donor because of the lack of a well-matched unrelated stem cell donor according to our transplant policy.
The Valencia schedule, consisting of a combination of reduced dose of thiotepa, Busilvex, and fludarabine, was used as a conditioning regimen, while the association of cyclosporine (0.75 mg/Kg/12 h continuous infusion from day -7, increased from day -1 to 1.5 mg/Kg/12 h continuous infusion), a short course of methotrexate (15 mg/mq on day 1 and 10 mg/mq on day 3-6 and 11), rabbit anti-thymocyte globulin (ATG) (5 mg/Kg/die from day -4 to day -1), basiliximab (20 mg on day 0 and day +4), and mycophenolic acid (15 mg/Kg twice daily) was administered as GVHD prophylaxis.
On day +100 after transplant, she developed acute gastrointestinal (GI) tract (stage 1, grade 2) GVHD successfully treated with steroids. Transplant-related complications due to the consequent use of a high-dose steroid for long time for GVHD included multiple episodes of reactivation of cytomegalovirus responded to antiviral therapy, sarcopenia, and fracture of the head of the femur surgically resolved.
On day +320 after transplant, the patient presented with nausea, vomiting, nystagmus, diplopia, and severe cutaneous purpura. A CT scan of the head showed a right multicystic cerebellar mass with perilesional edema compressing the fourth ventricle, also confirmed by brain MRI. As the lesions were not previously reported, we ruled out congenital abnormalities such as cavernous malformations. Since other differential diagnosis, including infectious (tuberculotic, echinococcal, and toxoplasmotic cysts) and neoplastic diseases, required a histological assessment, we proceeded to a surgical excision of one of the neuroradiological lesions.
An attempted biopsy of the cystic lesions, through suboccipital craniotomy, failed due to moderate bleeding during surgery. Histologic findings showed normal cerebellar tissue with polymorphonuclear leukocytes. Although the available specimen was not sufficient for all diagnostic tests, no neoplastic cells or fungal hyphae were seen. The fundus oculi assessment did not show cystis. Moreover, the quantiferon and TB skin test (or PPD test) were negative. Although prompt empiric antibiotic combination of meropenem and clindamycin was started, clinical and neuroradiological response was not achieved. High-dose intravenous trimethoprim-sulfamethoxazole for a suspicious cerebral toxoplasmosis, due to donor and patient IgG positivity before HSCT, was given after 20 days of antibiotic therapy. After two weeks of this therapy, continued clinical symptoms and MRI of the brain showed worsening of multicystic lesions with perifocal edema and initial cerebellar herniation. The patient also developed an intention tremor, bilateral hypoacusia, and severe haematological toxicity. In absence of clinical and radiological improvement and taking into account the patient's history of living in countryside, we applied the revised diagnostic criteria for Taenia solium infection and discovered that our patient presented a definitive diagnosis of NCC due to the neuroimaging presence of cystic lesions without a discernible scolex and enhancing lesion plus previous household contact with T. solium and neurological clinical manifestations of NCC. Moreover, in this case we documented the resolution of cystic lesions after cysticidal drug therapy (Figure 1), as confirmative criterion.
However, no cystic lesions were found in muscles, and the IgG Elisa test in blood and 3 consecutive stool samples were negative for T. Solium. The patient started empiric antiparasitic treatment with albendazole (400 mg PO BID) plus intravenous administration of dexamethasone (4 mg/day). Lumbar puncture was not performed due to high risk of hernia wedging and MRI signs of hydrocephalus. After 14 days, brain MRI control showed disappearance of some of the cystic lesions in the right cerebellar hemisphere and the reduction in size of some others. Patient was released from the hospital with no neurological symptoms, continuing albendazole therapy for four months.