Subcutaneous Masses as an Unusual Manifestation of Relapse in a Case of Atypical Chronic Lymphocytic Leukemia with Prolymphocytoid Transformation and Complex Karyotype: A Diagnostic Dilemma and Treatment Challenge.

BACKGROUND Most patients with chronic lymphocytic leukemia (CLL) are asymptomatic at diagnosis, but 10% present with B symptoms. Most patients have palpable lymphadenopathy, while 20-50% of the patients have hepatosplenomegaly. Cutaneous infiltrations in patients with CLL can be localized or generalized in the form of erythematous papules, plaques, nodules and, ulceration, which is uncommon. CASE REPORT We present the case of a 71-year-old man diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) with atypical immunophenotype and increased prolymphocytes (CLL/PLL), which was treated initially after white blood counts (WBC) doubling with Bendamustine and Rituximab for 6 cycles, and achieved complete remission. The patient relapsed after 6 months of completion of treatment, with multiple large subcutaneous masses, proved to be infiltration with the same atypical CLL/SLL on tissue biopsy, with pathologic features indicating disease progression. The lack of similar reported cases, and the aggressiveness of the tumor clinically and histopathologically, resulted in the decision to treat with Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone (R-CHOP) as a case of aggressive lymphoma, with complete remission clinically and radiologically. CONCLUSIONS We present a rare case of subcutaneous extramedullary masses of atypical CLL/SLL. The high proliferation index (Ki-67) and the increase of large cells are suggestive of aggressive progression of the disease; however, no frank features of Richter's transformation were noted. Based on this and because of the unusual aggressive-looking skin masses, the panel decided to treat the patient with R-CHOP. The impact of this presentation on the prognosis of the disease is not clear. To date, our patient has responded well to treatment with R-CHOP, with complete remission of the subcutaneous masses and on PET scan, but further follow-up is needed.