PEITC in End-Stage B-Cell Prolymphocytic Leukemia: Case Report of Possible Sensitization to Salvage R-CHOP

Abstract

Introduction: B-cell prolymphocytic leukemia (B-PLL) is a rare, aggressive leukemia distinct from chronic lymphocytic leukemia, with median survival of only 3 years. B-PLL is resistant to most chemotherapy and newer targeted therapies such as alemtuzumab and thalidomide. Phenylethyl isothiocyanate (PEITC) is a natural compound from horseradish with evidence for therapeutic potential in multiple leukemia types.

Case presentation: Here we present a case report of a 53-year-old man whose chronic lymphocytic leukemia transformed to end-stage B-PLL, disqualifying him for allogenic stem cell transplantation. He was treated with PEITC followed by salvage R-CHOP (Rituximab, Cyclophosphamide, Hydroxydaunorubicin [doxorubicin hydrochloride], Oncovin [vincristine sulfate], Prednisone or Prednisolone) chemotherapy, which led to normalized white blood cell count and disease stabilization that requalified him for allogenic peripheral stem-cell transplant therapy. We conducted a systematic review to analyze and interpret the potential contribution of PEITC to his unexpectedly favorable R-CHOP response. Following sequential 8 weeks of PEITC/pentostatin and 6 cycles of R-CHOP, the patient received allogenic peripheral blood stem cell transplant on an outpatient basis and remains well at the time of this publication, with no evidence of CD20+ small B-cells.

Discussion: Given the limited data for R-CHOP in B-PLL, this patient's recovery suggests presensitization of B-PLL cells toward R-CHOP, potentially justifying further investigation.

Figure 1.

Case Timeline. CT = computed tomography; ECOG = Eastern Cooperative Oncology Group score; FCR = Fc receptor; mos = months; PEITC = phenylethyl isothiocyanate; RBC = red blood cells; R-CHOP = chemotherapy consisting of rituximab, cyclophosphamide, hydroxydaunorubicin (doxorubicin hydrochloride), Oncovin (vincristine sulfate), prednisone or prednisolone; WBC = white blood cells.

Figure 2.

Biopsy specimen of splenic hilar lymph node shows a diffuse proliferation of small lymphoid cells (hematoxylin and eosin stain sample; magnification 400X [239 × 180mm] 72 × 72 DPI).

Figure 3.

Prolymphocytic leukemia tumor cells extending into splenic peri-nodal adipose tissue (hematolxylin and eosin stain sample; magnification 400X [239 × 180mm] 72 × 72 DPI).

Figure 4.

CD20 showing membrane positivity (immunohistochemical stain; magnification 400X [239 × 180mm] 72 × 72 DPI).

Figure 5.

CD5 showing strong, diffuse positivity (immunohistochemical stain; magnification 400X [239 × 180mm] 72 × 72 DPI).

Figure 6.

Computed tomography scan of extensive splenomegaly (135 × 135mm [96 × 96 DPI]).