An Unreported Co-existence
To the Editor: The synchronous double malignancies of renal cell carcinoma and acute myeloid leukemia (AML) have not been reported, according to a PubMed search. In the present report, a case of renal cell carcinoma and AML together is described and the literature is reviewed. Right radical nephrectomy was performed because of a renal mass in a 70year-old female patient. Pathology reported that the mass was renal cell carcinoma, and except surgery, there were no additional therapies. Four months after surgery, the patient consulted our department for increasing fatigue and abnormal complete blood count parameters: white blood cell count, 93 ร 10 9 /L; platelet count, 12 ร 10 9 /L; and hemoglobin level, 8.66 g/dL. Bone scintigraphy obtained 1 week before consultation was normal. There were 98% blastic cells with myeloid nature in a peripheral blood smear. Immunophenotyping from peripheral blood revealed that blasts were positive for CD33, CD38, and anti-HLA-DR. Cytogenetic examination showed 46, XX(16q+). Acute myeloid leukemia was diagnosed, and hydroxyurea was started for symptomatic control of white blood cell increment; the patient and her relatives did not accept the chemotherapy. The patient discharged with hydroxyurea and transfusion support as needed. The patient died 1 month after diagnosis.
It was reported in the literature that some unrelated malignancies could occur very close in time or rarely at the same time [1,2]. If two unrelated malignancies occur within a time interval shorter than 6 months, this association is considered to be ''synchronous '' [3]. Tsunematsu et al. estimated that the incidence of multiple primary cancers in children with primary cancers was 99.9 per 100,000 [4]. In the case we described here, renal cell carcinoma and AML were synchronous double malignancies. Our patient had not received chemotherapy or radiotherapy after surgery. For this reason, the association in our patient cannot be explained as a therapy-related development of a secondary malignancy [4]. The genetic abnormality observed in our patient was ''gain of chromosome 16,'' and this abnormality has been infrequently reported in renal cell carcinoma [5]. Abnormalities of chromosome 16 are also observed in acute myeloid leukemias, especially in subtypes having monocytic component. It is not possible to determine the association of this abnormality with any of these malignancies, because cytogenetic investigation was not performed at the time renal cell carcinoma was diagnosed. In conclusion, during follow-up of cases with malignancy, it should be kept in mind that symptoms that cannot be explained with the primary disease could be related to another malignancy.