A paper in the Journal of the American Academy of Dermatology reports three cases of what they call cutaneous Richter syndrome.
A 74-year-old woman with a 10-year history of CLL/small lymphocytic lymphoma presented to our dermatology clinic in 1999 with a nodule on her nose, which was clinically diagnosed as rhinophyma and treated with doxycycline. Five months later, a skin biopsy specimen of this lesion was taken and showed a dense monotonous infiltrate of small lymphocytes in the dermis and subcutis. The majority of the infiltrating cells were CD79a+ and CD20+ B cells that coexpressed CD5 and CD43. A diagnosis of cutaneous CLL was made. The patient’s white blood cell count was 19,500/μL at the time. The lesion gradually resolved after local radiation. In 2002, she developed multiple 2- to 3-mm red-blue papules on her face and on the pinnae of both ears. Skin biopsy specimens showed a dermal nodular infiltrate of large B cells expressing CD20, CD79a, CD43, and weak CD5. In the context of her history of CLL, cutaneous RS was diagnosed. Physical examination and computed tomography scans failed to reveal any lymphadenopathy or splenomegaly. Her white blood cell count was 18,500/μL with an absolute lymphocyte differential count of 13,900/μL (normal range: 1.2-4.0 × 103/μL). A bone-marrow biopsy specimen and aspiration also demonstrated CLL with large-cell transformation. Bone-marrow flow cytometry revealed a monoclonal B-cell population with an immunophenotype of CD19+, CD20+ (dim), CD5+, CD10–, CD11c+ (dim), CD23+, CD38+, and serum immunoglobulin lambda light chain (dim). A trisomy 12 abnormality was detected by fluorescence in situ hybridization on her bone marrow. The patient subsequently received chemotherapy with Cytoxan, Adriamycin, Oncovin, prednisone, and Rituxan. She achieved complete remission of her skin lesions. Repeated biopsy specimens of the nasal area in 2003 and 2004 did not show residual/recurrent lymphoma. The patient has remained asymptomatic with a follow-up of 8 years from the time of Richter transformation to last clinical visit.
A 63-year-old man presented with an erythematous rash on the right side of his back in 2002. His medical history was significant for CLL involving a right axillary lymph node diagnosed in 1995. A skin biopsy specimen showed a dermal nodular infiltrate of mainly large lymphocytes expressing CD20, CD79a, and CD43, with scattered small T lymphocytes in the background. The findings were consistent with cutaneous RS. His rash and lymphadenopathy resolved after two cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone. In 2006, the patient developed hepatomegaly and recurrent lymphadenopathy. Subsequent chemotherapy was stopped because of severe herpes zoster. Chromosome 11q and 13q deletions were detected in the peripheral blood by fluorescence in situ hybridization in 2007. He died of septicemia in 2007 after 5 years of follow-up.
A 61-year-old man presented with large bruises on his right wrist and forearm in 2000 associated with an elevated white blood cell count of 32,600/μL with 91% lymphocytes. Peripheral blood flow cytometry identified an abnormal monoclonal B-cell population expressing CD5, dim CD11c, CD19, dim CD20, CD23, CD45, and dim kappa light chain, consistent with CLL. The patient was treated with 6 cycles of fludarabine in 2002 and 2005 because of worsening lymphocytosis, anemia, adenopathy, and splenomegaly, and had an excellent response. In 2007, his peripheral blood and bone marrow showed recurrent CLL. No cytogenetic abnormality was found. Despite continued chemotherapy, he experienced worsening lymphadenopathy, thrombocytopenia, and anemia. Nodular opacities concerning for involvement by lymphoma were seen in his lungs. A cervical lymph node biopsy specimen showed CLL. In 2008, he developed multiple erythematous nodules and plaques on the chest. A skin biopsy specimen revealed a perivascular infiltrate of large atypical lymphocytes that labeled positive for CD20, CD43, and CD30, consistent with cutaneous RS. The patient decided to pursue palliative care and died 20 days after the diagnosis.
From these reports it is clear that this is a much more benign condition than true Richter syndrome and probably the appearance of large 'blast-like' cells in the skin does not carry the same importance as their occurrence elsewhere.