Local lymphatic metastasis for chromophobe renal cell carcinoma in a child after nephron-sparing surgery: a case report and literature review

Abstract

Objective To discuss the lymph node metastasis of chromophobe renal cell carcinoma (chRCC)in children. Methods One case of chRCC was reported. A eleven-year-old boy was admitted to our hospital on November 2, 2017 and presented gross hematuria 4 weeks. No mass was palpable in the abdomen and he felt tenderness in the left back. The ultrasound showed a solid mass in the lower pole of the left kidney. There were a lot of tortuous blood vessels in the tumor. Contrast enhanced CT suggested a mass of 4.5 cm×6.3 cm×4.9 cm. The left renal artery and vein were thickened. There was no enlarged lymph nodes were seen in both examinassions. During the operation, the tumor was located in the lower pole of the kidney. The frozen section diagnosis was benign renal tumor. Nephron-sparing surgery was performed. Results The pathology showed that the tumor cells had well-defined cell borders and characteristic peri-nuclear halos surrounded by eosinophilic cytoplasm that was positive for Hale's colloidal iron stain. Immunohistochemical studies were positive for EMA(+ ), Ki-67(5%+ ), CK19(+ ), CK(+ ), CD10(+ ), CD117(+ ), CD56(+ ). Fluorescence in situ hybridization showed absence of TFE3 protein, a strong immune marker of Xp11.2/TFE renal cell carcinoma. 1 year after the operation, contrast-enhancement magnetic resonance showed long T1 signal near the left renal hilum and the mass showed slight enhancement. ChRCC with regional lymph node metastasis hereby was considered. Intraoperatively, an approximately 2.5 cm×2.0 cm×2.0 cm mass was seen near the the left renal hilum. The tumor did not involve left kidney, abdominal aorta and inferior vena cava. The mass was completely removed and intro-operative fast-frozen pathology revealed chRCC. Nephron-sparing surgery was performed. Postoperative pathology report chRCC local lymph node metastasis . Follow-up at six months after resection, there was no recurrence or metastatic disease identified. Conclusions chRCC is rare in children and clinical stage is low with a good prognosis. Local recurrence and distant metastasis is rare. Key words: Chromophobe renal cell carcinoma; Children; Metastasis; Prognosis