Metastatic Clear Cell Renal Cell Carcinoma with an Unknown Primary in a Living Donor Kidney Transplant Recipient

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Austin Surg Case Rep. 2018; 3(2): 1027.

Metastatic Clear Cell Renal Cell Carcinoma with an Unknown Primary in a Living Donor Kidney Transplant Recipient

Elfadaly A*, Ardeshna N, Ekwenna O and Jorge Ortiz

Department of surgery, University of Toledo Medical Center, Toledo, USA

*Corresponding author: Elfadaly A, Department of Surgery, University of Toledo Medical Center, 3000 Arlington Avenue, Toledo, USA

Received: August 27, 2018; Accepted: September 17, 2018; Published: September 24, 2018

Abstract

Background: Renal Cell Carcinoma (RCC) commonly metastasizes, and unusual sites of spread are characteristic [1]. However, metastatic RCC without an identified primary site is extremely rare, and only a few cases have been documented [2,3]. We report the first case of clear cell RCC identified in retroperitoneal, supraclavicular, and mediastinal Lymph Nodes (LN) without a primary site in a kidney transplant patient.

Case Report: A 68-year-old patient presented with abdominal pain accompanied by weight loss, decreased appetite, and night sweats 6months post female living donor kidney transplant. A CT scan revealed retroperitoneal, supraclavicular, and mediastinal lymphadenopathy. An excisional supraclavicular LN biopsy stained for markers consistent with RCC (pancytokertain, PAX8, CD10, and vimentin). Subsequent karyotyping revealed a female aneuploid cell line and raised suspicion for a donor derived RCC. A primary site for the RCC could not be identified on imaging of the native and allograft kidneys. The patient expired waiting for the pathology report, and an autopsy was performed to identify the origin of the RCC. Autopsy could not identify a primary site and cytologic studies indicated that the cell line was derived from the patient. Additional chromosomal abnormalities identified in the cytologic studies (loss of VHL, PBRM1, SETD2, BAP1, CDKN2A/B TP53) narrowed the diagnosis to clear cell RCC.

Conclusion: Metastatic RCC can present without a primary site. IHC plays a vital role in making the diagnosis and cytologic studies can confirm the diagnosis and exclude the renal allograft as the origin in a kidney transplant patient.

Keywords: Metastasis; Renal Cell Carcinoma; Unknown Primary

Introduction

Worldwide, Renal Cell Carcinoma (RCC) is the ninth most common cancer and has an annual incidence of approximately 300,000 [4]. At the time of diagnosis, 25 to 30 % of patients with RCC have metastases [1]. The metastases can involve any organ, and unusual sites of spread are considered characteristic. Metastatic RCC without a primary site is rare and only a few cases have been documented.

Renal transplant is the treatment of choice in end-stage renal disease. Immunosuppression is required to improve graft survival, but it can increase the risk of RCC. We present a case of clear cell RCC with retroperitoneal, supraclavicular, and mediastinal lymph node metastases without a primary site in a 68-year-old status post living donor renal transplant patient.

Case Presentation

A 68-year-old male presented to the emergency department with severe epigastric pain six months post living donor renal transplant from his daughter-in-law. The patient had an uncomplicated transplant course and was in his usual state of health until the onset of fatigue and constant abdominal pain one week prior. He also reported weight loss, decreased appetite, and night sweats. Past medical history included hypertension, diabetes type II, basal cell carcinoma, and coronary artery bypass surgery. The physical exam was unremarkable except for jaundice and pallor. An abdominal CT scan, colonoscopy, and esophagogastroduodenoscopy were performed several days earlier at a different facility and did not show acute pathology. He was admitted for further workup due to the severity of the abdominal pain.

A repeat CT scan revealed retroperitoneal, supraclavicular, and mediastinal lymphadenopathy. Post-Transplant Lymphoproliferative Disorder (PTLD) was suspected, and a retroperitoneal fine needle biopsy was performed. The biopsy revealed vacuolated malignant cells with nuclear enlargement, hyper chromasia with prominent nucleoli, and easily identifiable mitotic figures. The tissue was stained for a battery of markers (Table 1). Instead of a lymphoma, both the Immuno Histo chemistry (IHC) and morphology results suggested a poorly differentiated carcinoma inconsistent with a primary site (Figures 1-3).

A PET scan was performed while the results for the retroperitoneal core biopsy were pending. It showed PET-avid adenopathy beginning at level of the thyroid cartilage and the left side of the neck extending inferiorly into the mediastinum. There was additional adenopathy in the retrocrural area bilaterally and in the peritoneum left of the aorta. The PET scan results and the patient’s clinical picture of weight loss, decreased appetite, and night sweats were suggestive of a high-grade B-cell lymphoma. An excisional supraclavicular lymph node biopsy was performed because of the conflicting findings.