RESUMEN
Primary cutaneous marginal zone lymphomas (PCMZL) frequently exhibit lymphoplasmacytoid/plasmacytic differentiation, implying the capacity to produce monoclonal immunoglobulins. As these paraproteins are secreted, and thus are measurable in blood and urine, they may correlate with disease burden and serve as tumour markers reflecting therapeutic response. This study retrospectively analysed the records of 23 patients with PCMZL. During treatment and follow-up, laboratory tests, including full blood count, lactate dehydrogenase, serum protein electrophoresis and turbidimetric analyses, were conducted. Thirty-nine percent of cases showed a suspicious serum protein electrophoresis in terms of paraproteinaemia. In 44% of cases the heavy and light chain restriction in tissue samples correlated with serological findings. Altogether, 89% of the PCMZL patients with paraproteinaemia eventually experienced a relapse, in contrast to 62% of the group without paraproteinaemia. This study analysed the incidence and clinical implications of paraproteinaemia in patients with PCMZL. A clear correlation was found between paraproteinaemia, tumour relapse and therapeutic intervention.