Klin Onkol 2026; 39(5): 344-355. DOI: 10.48095/ccko2026344.
Background: TEMPI syndrome was first described in 2011, and by 2025 at least 35 cases had been reported, but only two patients had a monoclonal IgM-type immunoglobulin. Observations: The patient had been monitored since 2015 for erythrocytosis in the context of obstructive bronchopulmonary disease. With the onset of erythrocytosis, the development of cutaneous telangiectasias was also observed. The critical moment leading to the diagnosis was swelling of the penis and scrotum, as subsequent abdominal CT revealed large perinephric fluid collections and led to suspicion of TEMPI syndrome. The genital swelling can be explained by rupture of perinephric lymphangiomatosis with the passage of fluid through the retroperitoneal space into the pelvic organs. In December 2024, the patient was diagnosed with Waldenström’s macroglobulinemia, corresponding to the finding of lymphoplasmacytic lymphoma in the bone marrow according to histomorphology and flow cytometry. Clonal variants in the MYD88 and CXCR4 genes were present in the bone marrow sample. Furthermore, a subclonal population (3–5% of cells) carrying mutations in other genes that are repeatedly affected in WM or lymphomas (ARID1A, EP300, MEF2B) was detected. The concentration of erythropoietin before treatment reached 5–20× the upper physiological limit. Before starting treatment, we confirmed arteriovenous shunts in circulation using contrast echocardiography. We treated Waldenström’s macroglobulinemia with rituximab and bendamustine. Due to repeated neutropenia, the doses of bendamustine were reduced, and therefore the number of treatment cycles was increased. After 14 months of treatment, the monoclonal immunoglobulin IgM decreased from 23 to 1.9 g/L. Telangiectasias disappeared. A control contrast echocardiographic examination no longer demonstrated arteriovenous shunts. The concentration of erythropoietin decreased, but remained elevated. The symptoms of TEMPI syndrome have regresed except for the size of the perinephric fluid collection, which remains the same and is now asymptomatic. In case the perinephric lymphangiectasias were to cause problems, we would proceed to a surgical solution via a connection with the peritoneal cavity. Conclusion: In our case of TEMPI syndrome, the size of the perinephric fluid collection did not change when Waldenström macroglobulinemia was suppressed, but all other symptoms resolved and the patient improved clinically, which was accompanied by an increase in albumin levels.