腎細胞癌罕見分支:病例分享
柯旭承¹、黃立華¹、林益聖¹、許兆畬¹、歐宴泉¹、童敏哲¹

童綜合醫療社團法人童綜合醫院 外科部 泌尿科 

Rare subtype of renal cell carcinoma: a case sharing

Hsu-Cheng Ko¹、 Huang Li-Hua¹、Yi-Sheng Lin¹、Chao-Yu Hsu¹、Yen-Chuan Ou¹、Min-Che Tung¹

¹ Division of Urology, Department of Surgery, Tungs' Taichung MetroHarbor Hospital, Taichung City, Taiwan 

Brief abstract

TFE3-rearranged renal cell carcinoma (RCC) was first recognized as a distinct subtype of RCC in the 2004 WHO classification of renal tumors. It is typically considered a pediatric renal tumor, accounting for 40% of RCC cases in that population. In adults, however, the incidence of TFE3-RCC is less than 2%. To date, only seven cases of patients older than 65 diagnosed with TFE3-rearranged RCC have been reported. Here, we present the case of a 70-year-old patient diagnosed with a TFE3-rearranged RCC larger than 11 cm, who underwent laparoscopic radical nephrectomy.

Background: Major subtypes of renal cell carcinoma (RCC) include clear cell, papillary and chromophobe type and constitute about 90% of all RCCs. [1] Translocation and transcription factor E3 (TFE3)-rearranged RCC (tRCC) is a rare form of RCC that involves chromosomal translocation of the Xp11.2 TFE3 gene with an unfavorable prognosis in adult. [2] In the present report, we introduce a case with both tRCC and prostate cancer (PCa).

Case presentation

A 70-year-old male with a history of hypertension presented to our outpatient department with hematuria and urine retention for months. Except for mildly impaired renal function and elevated PSA level (28.2 ng/mL), there were no major abnormal findings on the hemogram or biochemical tests. Ultrasound showed enlarged prostate measuring 4.0 x 3.9x 4.0 cm and a huge right renal tumor with a positive doppler signal. Chest and abdominal computed tomography revealed a huge heterogenous solid lesion measuring 11.8 cm with invasion of right renal vein. The tumor was confined in the Gerota fascia. Regional nodal metastasis was not detected (Fig. 1). However, multiple solid and calcified nodules were found at bilateral lungs, size up to 0.6 cm (Fig. 2A). Whole body bone scan was negative for prostatic metastasis. The patient underwent a staged operation of transrectal ultrasound of prostate (TRUS-P) biopsy and transrectal transurethral resection of prostate (TURP) and subsequent laparoscopic right radical nephrectomy. The final pathologic results of the TRUS-P biopsy and TURP confirmed prostatic adenocarcinoma, Gleason score 4+5 and grade group 5. On the other hand, specimen from laparoscopic right radical nephrectomy measured 11 x 6.5 cm in size and revealed hyaline eosinophilic cytoplasm with papillary and solid alveolar structures with sporadic calcified material. Additionally, strong positive nuclear immunohistochemical staining of TFE3 was observed. Immunohistochemically, positive results were observed for CAIX, PAX8, AMACR while CK7 are negative. Postoperatively, the patient has started androgen deprivation therapy for controlling PCa. Three months later, there was no tumor recurrence found in the chest and abdominal CT scan. Multiple solid nodules at bilateral lungs were stable without enlargement (Fig. 2B). Differential diagnosis for the lung nodule included metastatic prostatic adenocarcinoma, metastatic RCC, primary lung adenocarcinoma or just benign lesion. We will perform biopsy or even wedge resection if the nodules grow in the future.

Discussion

TFE3-rearranged RCC was first accepted as a distinct subtype of RCC in the the 2004 WHO classification of renal tumors [3]. TFE3-rearranged RCC mostly occurs in pediatric populations accounting for 40%, whereas account for approximately less than 2% of adult RCCs with a median age of onset of 33 years [4,5]. Furthermore, it was reported that only seven cases were observed in patients aged >65 years [6]. A recent meta-analysis conducted by Cheng et.al demonstrated that prognosis between children and adults and between females and males dose not reach statistical significance [7]. Like other types of RCCs, presence of lymphadenopathy and distant metastasis indicates poor prognosis. In an observation study consisting of 46 patients with TFE3-rearranged RCC mostly staged T1 and T2, overall survival rates in 1 year, 3 years and 5 years were 97.4%, 88.8% and 88.8%, respectively [8]. The result was equal to the 5-year overall survival of RCCs. (SEER Cancer Statistics Review, 1975–2014, based on November 2016 SEER data submission, posted to the SEER website, April 2017: National Cancer Institute.).

On CT imaging, tRCC generally have a well-defined margin and heterogeneous interior due to solid and cystic components with hemorrhage, necrosis, and calcifications. The solid portions typically enhance less intensely compared with the adjacent cortex during all three phases of enhancement and enhance more intensely compared with the adjacent medulla—except during the delayed phase [9]. In non-metastatic tRCC, surgical approach is the first-line treatment. Whereas, in those metastatic tRCC, neoadjuvant VEGFR-TKI plus immune checkpoint inhibitor (ICI) could be considered prior to surgery and further reduce tumor volume and intraoperative bleeding [10,11]. In our case with both PCa and tRCC, to relieve his initial symptoms, e.g. difficult urination, after considering age and body status, we performed TRUS-P and TURP first. Two weeks later, subsequent laparoscopic right radical nephrectomy was smoothly done and the patient recovered well. Regarding suspected small-sized lung nodules, we chose to follow up image studies and clinical situation rather than applying neoadjuvant or adjuvant TKI alone or plus ICI in the beginning. It seems that lung nodules were stable on follow-up CT scan images 3 months later.

Conclusion:

TFE3-rearranged RCC is a rare type of RCC and less than 10 cases older than 65 years old have been reported. The case presents a double cancer of rare TFE3-rearranged RCC and prostate cancer. This report highlights that preoperative evaluation, clinical treatment decision, delicate radical excision, and postoperative monitoring are essential for managing such tumors.