ATLL, an aggressive mature T-cell leukemia/lymphoma caused by HTLV-1, affects an estimated 10 to 20 million globally, posing a significant public health concern, especially in endemic regions like South and Central America. Since Shimoyama’s 1991 classification, efforts have focused on refining clinical subclassifications to encompass diverse presentations observed across ethnicities and endemic regions worldwide. We present a case series of Hispanic patients from endemic areas demonstrating primary bone involvement.


We conducted a retrospective analysis of ATLL patients with bone involvement diagnosed between January 2010 and December 2023 at the University of Miami, USA, and Arzobispo Loayza Hospital, Peru. We described sociodemographic and clinical-pathologic characteristics. Treatment response adhered to Tsukasaki et al. (JCO 2009) criteria, and survival curves were estimated using the Kaplan-Meier method, with statistical significance assessed via the Log rank test.


A total of 12 patients with ATLL manifesting as either extranodal primary-bone disease (n=9), or bone-only disease upon relapse in patients with acute (n=2) and lymphomatous ATLL (n=1). In regards to the extranodal primary-bone disease manifestation, in our cohort, 44% of patients were younger than 50-years-old (range 31-48-years-old), 56% had diffuse bone disease and 44% localized bone disease but that progressed to diffuse bone disease upon relapse. Most patients (89%) did not have clinical lymphadenopathy or bone marrow involvement (67%), high calcium and LDH levels were found in 25% and 38% of patients, respectively. Three patients had HIV co-infection. The median overall survival time and overall response rate to first- or second-line therapy were 16.8 months and 67% (complete response=22%), respectively. All patients ultimately died from disease progression.


Our case series emphasizes the necessity of including ATLL in the diagnostic evaluation of patients with diffuse osteolytic lesions from HTLV-1 endemic areas. Additionally, we propose a clinical subclassification for extranodal primary-bone lymphomatous ATLL-variant.