Recurrent Isosporiasis as a Portent of Adult Human T-Cell Lymphoma in a Patient with HTLV-1

Abstract

Purpose: A 76-year-old female from the Caribbean Islands presented to our medical center with nausea, vomiting, diarrhea, and 32 pounds of weight loss over the past 4 months. The patient reported a past medical history of chronic hepatitis B. Extensive work-up of her symptoms, including stool studies were initially negative. Endoscopy and colonoscopy revealed normal duodenal biopsies and chronic gastritis with intestinal metaplasia of the stomach. Serum gastrin and 5-HIAA levels were normal. The patient was readmitted the following month with similar symptoms at which time oocysts for Isospora were identified from stool modified acid-fast stain. She was started on pyrimethamine and leucovorin with significant symptomatic improvement. Given the presence of isospora, an extensive workup for suspected immunocompromised state and possible underlying malignancy was initiated. She was found to be positive for the HTLV-1 virus. A CT revealed a soft tissue density within the mediastinum and concern was raised for lymphadenopathy versus a mediastinal mass. Bronchial lavage and EBUS biopsy of the lesion were negative for malignant cells. A VATS was planned to obtain further biopsies of this mediastinal lesion, but was delayed due to the patients poor health. Over the next six months the patient was re-admitted several times for recurrent diarrhea and isosporiasis. Bactrim, pyrimethamine and leucovorin were given for recurrent isosporiasis. Finally, she presented with jaundice, ascites and worsening liver function tests. Paracentesis was performed and revealed malignant cells consistent with acute adult T-cell lymphoma (ATL). Results of immunohistochemistry stains supported the diagnosis; neoplastic cells were positive for CD-2, CD-4, CD-5, and CD-25. Given the overall poor prognosis associated with acute ATL and the advanced age of the patient, the family opted for palliative care. The patient developed liver failure, renal failure, along with hypercalcemia and expired. ATL is a rare peripheral T cell neoplasm associated with infection by the human T-lymphotropic virus-1 (HTLV-1). One study suggested that the lifetime risk of developing ATL in those infected with HTLV-1 before the age of 20 was 4%. There have been case reports in the Japanese literature describing the association of isosporiasis with ATL. However, there is no clear documentation in the literature of the association of isospora with HTLV-1. Given our patient's presentation and her rapid progression to acute ATL, we suggest that the presence of recurrent isosporiasis or other opportunistic infections in a patient with HTLV-1 be looked upon with suspicion as a sign of impending ATL.