左側腎臟惡性血管周上皮樣細胞腫瘤之診斷 – 病例報告
蘇楷森1、張延驊1,2、黃志賢1,2
1臺北榮總泌尿部；2國立陽明交通大學書田泌尿科學研究中心
The Diagnosis of Left Kidney Malignant Perivascular Epithelioid Cell Tumor with Prominent Sarcomatoid Differentiation – A Case Report
Kai-Sen Su1, Yen-Hwa Chang1,2, William J. Huang1,2
1 Department of Urology, Taipei Veterans General Hospital;
2 Department of Urology, School of Medicine and Shu-Tien Urological Science Research Center, National Yang Ming Chiao Tung University
Introduction:
Perivascular epithelioid cell tumor (PEComa) is a mesenchymal neoplasm that can display an aggressive clinical course. PEComa arising from kidney is extremely rare, and the features of which are poorly defined owing to limited prior reports. Herein, we report a case of left kidney malignant perivascular epithelioid cell tumor with prominent sarcomatoid differentiation, and the challenges we encountered along the clinical course.
Case report:
This is a 51-year-old female with no previously known systemic diseases. She was robust until early 2022, epigastric pain was firstly noted. She visited other hospital, where computed tomography (CT) was arranged on 2022/1/28 and revealed a huge cystic tumor at upper pole of left kidney with ring calcification, hemorrhage, and suspicious renal vein invasion. CT-guided biopsy of the mass lesion failed to provide pathological diagnosis due to necrotic tumor feature. The patient then came to our hospital for second opinion. After well discussion, left open radical nephrectomy was scheduled.
However, she developed intermittent left flank pain before the scheduled date of surgery. She prompted to our emergency department on 2022/3/8. CT scan was done and revealed huge left renal tumor, with renal vein and collecting system invasion, with newly identified multiple liver and lung metastases, indicating rapid disease progression compared to previous image on 2022/1/28. Under the impression of left renal tumor with rapid progression to metastatic disease, definitive pathological diagnosis before systemic therapy has become the primary objective, and radical surgery was withheld.
Left ureteroscopic biopsy for renal tumor was performed on 2022/3/10, with pathology report of carcinoma, but difficult to determine origin. Sono-guided biopsy of the liver metastatic lesion was done on 2022/3/14, with pathology report of epithelioid and spindle cell neoplasm, also failed to have definite diagnosis. CT-guided biopsy for left renal tumor was done again on 2022/3/18 with the pathology report of epithelioid and spindle cell neoplasm. This case was presented at multidisciplinary teams (MDT) tumor boards and debulking surgery to obtain definite diagnosis was recommended. Left open radical nephrectomy was performed on 2022/3/28 with uneventful recovery. Final pathology was initially reported as undifferentiated pleomorphic sarcoma (UPS), and later confirmed the diagnosis as malignant perivascular epithelioid cell tumor with prominent sarcomatoid differentiation following FusionPlex Sarcoma Expanded Assay revealed TFE3-PRCC gene fusion. The patient was then transferred to oncologist’s service for further systemic therapy.
Systemic therapy with Pembrolizumab was given for 2 courses and then switched to ifosfamide, mesna and epirubicin (IMEpi) combination for 1 course due to poor treatment response. However, further systemic therapy could not be continued due to rapid disease progression-related critical condition. The patient was discharged against medical advice on 2022/6/22.
Conclusions:
Primary renal malignant PEComa is a rare mesenchymal tumor with unique histopathological characteristics. Kidney TFE3-PRCC gene fusion-related PEComa is extremely rare, and the definite diagnosis could hardly be made before extensive immunohistochemical workup with adequate tissue. Such case reminds us the role of upfront surgery when definite pathological diagnosis of a metastatic disease was challenging to obtain before systemic therapy.