Thalidomide-induced serious RR interval prolongation (longest interval >5.0 s) in multiple myeloma patient with rectal cancer: A case report

Abstract

Primary secondary tumor increased recently with the use of immunomodulatory drugs in patients with multiple myeloma (MM). However, MM with prior diagnosis of primary secondary tumor is relatively rare. In this study, we reported an MM patient with prior diagnosis of rectal cancer. In brief, an 85-year-old man was first diagnosed with rectal cancer. Given the age, heart failure and small-cell hypochromic anemia (hemoglobin level: 54 g/L), rectal cancer resection was not advised and symptomatic treatments were performed (including sufficient iron supplementation). Eight months later, the patient was diagnosed with MM due to worsening anemia. Anemia and heart failure were corrected after three cycles of treatment with thalidomide, dexamethasone and capecitabine. Radical resection of rectal carcinoma (Hartmann) was finally performed due to acute abdominal distension. Meanwhile, RR interval prolongation (longest interval >5.0 s) and atrial fibrillation occurred in the fifth cycle treatment. One month after discontinuation of thalidomide, RR interval returned to normal range, while atrial fibrillation developed into persistent atrial fibrillation.

Keywords: RR interval prolongation; multiple myeloma; rectal cancer.

Figure 1

Clinical and histopathological appearances. (a and b) HE staining results from thickened rectum showing adenocarcinoma. (c) Bone marrow cytology results showing increased plasmocyte. (d–g) Pathological and immunohistochemical results of bone marrow showing CD138 (+), CD38 (+), CD56 (partial +), Kappa (+), myelodysplastic activity and increased plasmocyte. (h) Excised rectal cancer.

Figure 2

ECG of patient during treatment. (a) Normal ECG before atrial fibrillation and RR interval prolongation; (b) the first holt result showing atrial fibrillation occurring during thalidomide treatment; (c) the first holt result showing serious RR interval prolongation (RR interval = 5.2 s) during thalidomide treatment; and (d) atrial fibrillation did not disappear after withdrawal.