Case history/examination:
A 67-year-old woman presented with increased serum creatinine level and
elevated erythrocyte sedimentation rate (ESR), which was detected during
routine follow-up. She did not complain of fever, weight loss, or any
urinary symptoms. Except for an impalpable spleen, physical examination
was otherwise normal. Her past medical history was positive for mild
hypertension and antiphospholipid antibody syndrome (APAS) that had
resulted in habitual abortion and thrombophlebitis of both lower
extremities during pregnancy. The patient also reported a history of
splenectomy following a motor vehicle accident. Approximately four years
ago, during routine examinations, an abnormally high ESR
(>75 mm/hour) was accidentally noticed, for which,
considering her history of APAS, 10 mg oral prednisolone and 50 mg oral
azathioprine was administered on daily basis. Although the patient had
remained symptomless, a gradual rise in ESR was observed after one year
from initiation of medical treatment. Further evaluation with computed
tomography (CT) imaging had revealed a left renal mass that measured
approximately 2-3 cm in size; however, the patient had refused to
undergo further assessment and continued receiving medical treatment.