A case of chromophobe renal cell carcinoma in a 12-year-old girl

Abstract

Renal cell carcinoma (RCC) accounts for only 2–6 % of pediatric renal tumors. Chromophobe RCC is very rare in pediatric patients, with only a few cases reported. A 12-year-old girl who had abdominal and left flank pain visited the pediatric clinic of a local hospital. A uniformly enhanced tumor measuring 2.5 cm × 2.3 cm was found on computed tomography. On magnetic resonance imaging, T2-weighted images showed a solid tumor with hyperintensity suggesting intratumoral necrosis. We considered RCC and Wilms' tumor as differential diagnoses, but we could not reach a definitive diagnosis from the radiographic findings. We then performed right partial nephrectomy with regional lymph node dissection. The histopathological diagnosis was pT1aN0 chromophobe RCC. After the surgery, no recurrence has been observed for 15 months.

Introduction

Renal cell carcinoma (RCC) in children is generally thought to be rare, accounting for only 2–6 % of pediatric malignant renal tumors [1]. Previous reports showed that pediatric RCC presents histological features different from adult RCC, although papillary RCC is the most frequent type [2]. Chromophobe RCC in children is very rare with, to the best of our knowledge, only a few cases reported in the literature.

Case report

A 12-year-old girl presented in a pediatric clinic with abdominal and back pains. She had no personal or family history of malignant disease. Ultrasonography of the abdomen found a 2.5-cm mass with blood flow in the right kidney. Contrast-enhanced computed tomography (CT) showed a uniformly enhanced tumor measuring 2.5 cm × 2.3 cm in the early phase, and attenuation in the delayed phase (Fig. 1). On magnetic resonance imaging (MRI), T1-weighted images showed a well-defined hypointense mass. T2-weighted images displayed a heterogeneously hyperintense tumor with necrosis. She was referred to our department for treatment of the right renal tumor (Fig. 2).

Fig. 1.

Contrast-enhanced abdominal computed tomography. A tumor measuring 2.5 cm × 2.3 cm uniformly enhanced in the early phase (a) and attenuated in the delayed phase (b)

Fig. 2.

Magnetic resonance imaging (MRI). a T1-weighted image shows a well-defined hypointense mass. b T2-weighted image shows hyperintense mass

There were no abnormal data, including neuron-specific enolase (NSE) alpha-fetoprotein (AFP), in her initial laboratory test. After discussion with radiologists, we considered RCC and Wilms' tumor as differential diagnoses from the radiological findings. We decided to treat her with nephron-sparing surgery (NSS), since we thought that the tumor was most likely to be RCC judging from her age, the tumor size and radiographic information. Therefore, we performed right partial nephrectomy. The right renal hilar and paracaval nodes were dissected for staging in case of Wilms' tumor or Xp11 translocation RCC. Macroscopically, the specimen was a 2.5 cm × 2.0 cm, uniformly ocher and glossy tumor with a negative surgical margin (Fig. 3). Microscopically, the tumor cells had clear, eosinophilic cytoplasm and oval, enlarged nuclei with perinuclear halos on hematoxylin and eosin staining (Fig. 4). The tumor cells were immunohistochemically positive for cytokeratin AE1/3 and cytokeratin 7. Vimentin, transcription factor E3 (TFE3), Wilms' tumor 1 protein (WT-1), and lymphocyte common antigen (LCA) were negative. The pathological diagnosis was chromophobe RCC, grade 2, pT1a, pN0. She was discharged 8 days after the surgery without any postoperative complications. After the surgery, no recurrence has been observed for 15 months. Her serum creatinine level remains within the normal range.

Fig. 3.

Macroscopic finding of the partial nephrectomy specimen: a uniformly ocher and glossy tumor

Fig. 4.

Microscopic appearance of the right renal tumor (H&E stain, ×400). Clear, eosinophilic cytoplasm and oval, enlarged nuclei with perinuclei halos are shown

Discussion

Although we considered the renal masses to be RCC rather than Wilms' tumor as mentioned above, biopsy might be indicated before surgery. According to a recent international consensus panel [3], tumor biopsy is recommended in most cases with a small renal mass except in patients with imaging or clinical characteristics indicative of pathology since there is strong evidence that renal mass biopsy can achieve very high accuracy in identifying malignancy [3]. However, the United Kingdom Children’s Cancer Study Group [4] reported that of 182 children who had percutaneous cutting needle biopsy, 20 and 19 % of patients had a fall in hemoglobin and local pain, respectively. Furthermore, one child required emergency nephrectomy due to massive bleeding, another had tumor rupture and subsequently died, and a third developed a needle track recurrence 8 months after the biopsy [4]. Thus renal mass biopsy for children should be carefully indicated and performed only when absolutely necessary.

The standard treatment for localized RCC is surgical resection. NSS is thought to be a favorable approach for patients with T1 disease. Cook et al. reported 5 pediatric patients with RCC smaller than 4 cm who were treated with NSS [5]. All patients obtained 100 % recurrence-free survival (RFS) and overall survival (OS) during the follow-up period. This report suggested that NSS was well tolerated and provided favorable oncological outcomes in pediatric patients with small RCC tumors. A recent study [6] with 304 children aged 0–17 years with RCC from a large national cancer database revealed that survival following partial nephrectomy was 100 % at 1 and 5 years.

In the case of a unilateral Wilms' tumor, radical nephrectomy is considered as standard treatment [7]. Recently, several studies showed the efficacy of NSS against unilateral Wilms' tumors [8–10]. Cost et al. compared the oncologic outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) for unilateral WT patients [8]. In stage I cases, there were no significant differences in RFS (89 versus 83.1 %) and OS (95 versus 95 %) between the two groups. Furthermore, postoperative renal function in the PN group was better than that in the RN group [9]. Thus NSS is recommended for pediatric patients with renal tumors even if the histology is Wilms' tumor.

We reviewed the literature and found only 5 cases of chromophobe RCC in childhood (Table 1) [2, 10–13]. In the current case, the patient age and tumor grade were in agreement with those of the previous reports. There has been no recurrence during follow-up in any case. The present case suggests that NSS provides favorable outcomes for pediatric patients with localized chromophobe RCC as in adults.

Table 1.

Reported cases of chromophobe RCC in children and young adults

References	Sex	Age (y.o.)	Grade	Stage	Tumor size (cm)	Treatment	Outcome (months)
Fujii et al. [12]	M	12	2	I	4.5	RN	NED (12)
Indolfi et al. [11]	F	10	N.I.	I	N.I.	RN	NED (49)
Selle et al. [2]	M	4	N.I.	II	>10	RN	NED (7.2)
Campus et al. [13]	M	7	N.I.	I	3.5 × 3.0	RN	NED (36)
Baek et al. [14]	M	16	N.I.	II	9.0 × 8.0	RN	NED (132)
Our case	F	12	2	I	2.5 × 2.0	PN + LND	NED (12)

N.I., not indicated, RN radical nephrectomy, PN partial nephrectomy, LND lymph node dissection, NED no evidence of disease