Hydroa vacciniforme‐like lymphoproliferative disorder: A clinicopathological, immunohistochemical, and prognostic study of 24 cases in China

Hydroa vacciniforme‐like lymphoproliferative disorder (HV‐LPD) is a rare cutaneous disease associated with Epstein–Barr virus infection. We retrospectively analyzed the clinical presentation, histopathological characteristics, and prognostic study of HV‐LPD in 24 Chinese patients. All patients presented with recurrent papulovesicular and necrotic eruptions on the face, neck, and extremities, with 11 showing systemic symptoms. Twenty patients were diagnosed with HV‐LPD in childhood (age < 18 years) and four in adulthood (age ≥ 18 years). The median age at diagnosis was 8.5 years old (range, 2–50). Histopathology revealed variably dense lymphocyte infiltration throughout the dermis. All cases were strongly positive for CD3 and Epstein–Barr encoding region based on in situ hybridization. Of 18 cases with a T‐cell phenotype, 15 harbored monoclonal rearrangements in T‐cell receptor (TCR) genes. Four cases with a natural killer cell phenotype carried polyclonal rearrangements in TCR genes. Among 24 patients, eight (33.3%) received chemotherapy, two (8.3%) allogeneic hematopoietic stem cell transplantation, and both are currently alive without disease. The median follow‐up period was 24 months (range, 7–120) and 23 patients were available: 15 (62.5%) were alive, and eight (33.3%) had died. Fourteen cases had a relapse of disease and three developed lymphoma within 24 months of diagnosis. The mean survival time of childhood‐onset patients was longer than that of adult‐onset patients (36.4 vs. 20.8 months). In summary, the wide clinical course and representative presentation of cases in our center reflect the pedigree characteristics of HV‐LPD. Allogeneic hematopoietic stem cell transplantation should be a preferred choice for relapse and refractory patients due to the poor effect of chemotherapy. Adult‐onset and high serum EBV DNA loads may indicate an increased risk of aggressive disease in patients with HV‐LPD.