Hydroa vacciniforme-like lymphoproliferative disorder: A study of clinicopathology and whole-exome sequencing in Chinese patients.

Hydroa vacciniforme-like lymphoproliferative disorder (HVLPD) encompasses a rare group of Epstein-Barr virus (EBV)-associated lymphoproliferative diseases. To define the clinical and pathologic characteristics of HVLPD and to identify mutant genes that may be related to the development of HVLPD. Clinical data and archived formalin-fixed, paraffin-embedded tissue were obtained from 19 patients. Specimens were analyzed by immunohistochemistry and in situ hybridization to detect EBV-encoded RNA (EBER1/2) and for T cell receptor (TCR) gene rearrangements. Whole-exome sequencing (WES) analysis was also performed in this study. Thirteen patients survived between 3-58 months (median, 21 months) during the follow-up. Six patients who were almost adults (>15 years old) and died of the disease presented with facial edema. Lactate dehydrogenase (LDH) levels were elevated, and the TCR gene rearrangement test was positive more frequently in the patients who died. Compared with Chinese patients in a similar previous report, our patients had significantly higher proliferation (in all cases, the Ki-67 index was greater than 10 %) and a more aggressive clinical course. Moreover, after WES and Sanger verification, STAT3, IKBKB, ELF3, CHD7, KMT2D, ELK1, RARB and HPGDS were screened out in our patients. HVLPD refers to a heterogeneous group of cutaneous lymphoproliferative diseases with different clinical and pathological features that affect patient outcomes. Gene mutations may be correlated with the development of HVLPD, and our study may provide new therapeutic targets for HVLPD.