A 68-year-old male patient was admitted to our hospital with a history of ambiguous low back pain for the past two months. He had no medical history of abdominal trauma or operation. Physical examination revealed no abnormality of liver, renal function and blood and urine sediment analysis. He then underwent an ultrasound examination of the urinary system(Fig. 1). Gray-scale ultrasound image demonstrated a separated cystic mass in the upper part of the left kidney. The mass was approximately 9.1 × 6.4 cm in size with an irregular shape and slightly unclear margin. Calcification can be seen on some septum. And some septum is thicker, the thickest is about 6 mm. Color Doppler displayed dot-linear blood flow signals in the mass septum. For further diagnosis, the patient agreed to undergo CEUS. A 1.2 mL contrast agents (SonoVue, Bracco SpA, Milan, Italy) suspension was injected through his cubital vein followed by a 5 mL saline flush. A Resona7 ultrasound system (mindray, China) with an SC6-1U (1–6 MHz) transducer was used only for the examination. The mechanical index setting was 0.078 for CEUS. The depth, gain, and focus are thoroughly adjusted. Taking normal renal parenchyma as a reference, the contrast arrival time to the renal lesion was 14 seconds after administration of the contrast agent, and the septum of the lesion was homogeneously hyper-enhanced in the cortical phase. In the medulla and delayed phase, the lesion displayed hypo-enhancement. The combination of lesion B-Mode(separated cystic lesion) and enhancement pattern (hyper-enhancement in the cortical phase, and hypo-enhancement in the medulla and delayed phase after contrast agent administration) yield a diagnosis of cystic renal carcinoma.
Laparoscopic radical left nephrectomy was performed to remove the mass, and serious adhesion between the left kidney and surrounding tissues was found. Subsequently, the left kidney adhesion release was performed. The renal mass was mainly located in the upper part of the left kidney and measured 9.0 cm x 8.0 cm x 7.0 cm. The tumor cyst fluid is clear.
Microscopic examination revealed a tumor that was composed of blood and lymphatic vessels with polycystic spaces, thin wall, and dyed red lymph and blood cells within the lumen(Fig. 2). Immunohistochemistry staining results were as follows: CD31(+), CD(34+), and ERG(+), PAX8(+), D2-40(±), and no expression for CA9(-), CK7(-)in the lesions. The final pathological diagnosis of the lesion was a renal hemolymphangioma.
No evidence of malignancy was found. The postoperative course was uneventful. The patient was discharged 12d after surgery. He is currently enjoying normal life without complaints or signs of recurrence.
In this paper, ethical approval was not necessary, as this article is a case report, which is based on the clinical information of the patient. Because our case is not referred to as the patient’s privacy, informed consent is not necessary, and the patient gave their permission for publication of the case.