CASE REPORT

A 81-year-old female patient had a 2-year history of painful lesions on both legs. She complained of asthenia, decreased appetite and changes in the sleep-wake cycle. Physical examination evidenced multiple brownviolet nodular lesions on both legs. Some of the lesions were ulcerated, with drainage of purulent and serosanguineous secretion (Figure 1). There was non-pitting edema extending throughout the length of the legs. During hospitalization, atrial flutter and decompensated heart failure were diagnosed. Histopathological examination showed extensive dermal infiltration by malignant neoplasm of large cells with voluminous, irregular nuclei, prominent nucleoli and scant cytoplasm (Figure 2). Immunohistochemistry showed strong expression of CD20, negativity for CD3, and high levels (>80%) of Ki67 index of cell proliferation (Figure 3). Computed tomography of the abdomen and thorax showed no abnormalities.

FIGURE 1 A. Violet-colored erythematous nodular lesions with central ulceration on the anteromedial region of the right leg; B. More abundant, similar lesions on the anterior region of the left leg 

FIGURE 2 A. Tumor infiltrate involving the whole dermis and presence of Grenz zone; B. Cells with pleomorphic hyperchromatic nuclei seen in more detail 

FIGURE 3 A. Positive immunohistochemistry for CD20; B. High levels (>80%) of Ki67 index of cell proliferation 

DISCUSSION

The diagnosis of primary cutaneous large B-cell lymphoma, leg type (PCLBCL-LT) was confirmed by clinical, histological and immunohistochemistry findings. These lymphomas are malignancies of the lymphoreticular system that originate from three lymphoid cells lines: B, T and NK (natural killer). Primary cutaneous lymphomas are neoplasias restricted to the skin. According to the WHO-EORTC classification (2008), cutaneous B-cell lymphomas are classified into three types: marginal zone primary cutaneous B-cell lymphoma; centrofolicular primary cutaneous lymphoma and PCLBCL-LT. The PCLBCL-LT corresponds to 4% of all cutaneous lymphomas and to 20% of all primary B-cell lymphomas.^1,2 Clinically, it presents itself as single or multiple violet-colored erythematous tumors on one or both legs. Affection of the lymph node, bone marrow and central nervous system may rarely occur in PCLBCL-LT. The five-year survival is 50%.^3-5 Histological examination of tumor lesions shows a diffuse, monotonous cellular infiltrate of immunoblasts, without epidermotropism. The presence of the normal collagen band in the superficial dermis, separating the epidermis from the dermal lymphocytic infiltrate (Grenz zone) is a common finding in cutaneous B-cell lymphomas. Neoplastic cells are positive for CD20, CD79a and negative for CD3. There is strong expression of BCL-2, BCL-6 and MUM-1. Anti-Ki67 antibodies are also an important aid in the diagnosis of B-cell lymphoproliferative processes.^1,6,7 Currently, the R-CHOP chemotherapy regimen (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) is the most widely accepted treatment for PCLBCL-LT.^2,8,9 The alternative COP chemotherapy regimen (cyclophosphamide, vincristine and prednisone) was chosen due to the presence of heart failure (which contraindicates the use of doxorubicin), the delay in the release of the immunohistochemistry examination results (required for the release of rituximab), and, especially, the rapid progression of the disease. There was a partial regression of cutaneous lesions and reduction of cutaneous infiltration after the first cycle of chemotherapy. However, the patient acquired nosocomial pneumonia, progressed to septic shock and died four months after the diagnosis of PCLBCL-LT.