The present case study was conducted on a 74-year-old man who visited our department due to a left renal and retroperitoneal
tumor on computed tomography (CT). The patient was diagnosed with left
renal cancer lymph node metastasis and was hospitalized a few weeks prior to surgery due to
fever, malaise, and severe appetite loss. Biochemical laboratory findings at admission showed markedly high levels of
inflammation. The cause of high inflammatory response was
paraneoplastic syndrome.
Tumor resection was considered necessary, and left
nephrectomy and
lymphadenectomy were performed; however, it did not improve the inflammatory response. After operation, positron emission tomography-CT revealed hyperaccumulation of 18F-fluorodeoxyglucose in the bone marrow throughout the body. Pathological examination of the resected specimen and bone marrow aspiration revealed the coexistence of idiopathic multicentric
Castleman disease (CD) and
renal cancer.
Prednisolone and
tocilizumab were administered for idiopathic multicentric CD and a
tyrosine kinase inhibitor for
renal cancer; however, they had poor
therapeutic effect, and the patient died. CD is characterized by systemic symptoms due to the overproduction of
interleukin-6. Treatment for idiopathic multicentric CD involves
steroid and anti-interleukin-6
therapy. The diagnostic criteria for CD require the exclusion of malignant
tumors although there are some cases in which CD and malignant
tumors coexist. The prognosis for CD is relatively good; however, as in this case, the prognosis of CD coexisting with uncontrollable
renal cancer is insufficient due to poor improvement in the inflammatory response.