The described patient’s course documents the successful interdisciplinary care and inter-institutional cooperation between urology and vascular surgery in the treatment of a rare exemplary case. It was characterised by a complex and advanced tumour growth of a clear cell RCC with IVC tumour thrombus in a horseshoe kidney plus a doubled right organ. Such combination of an uncommon clinical manifestation of a malignant renal tumour lesion with two further rare anatomic variants or malformations of the kidney is presented for the first time in the available English-speaking literature.
Horseshoe kidneys can be characterised as an anatomic variant—in particular, an embryological fusion of the lower poles with usually non-malformated ureters.
RCC takes the third position of urological malignant tumour lesions and can originate from epithelial cells of renal parenchyma. The clear cell carcinoma is the most common type (70%) whereas other types are chromophile and chromophobe carcinomas as well as the rare neuro-endocrine carcinoma. RCC may comprise approximately 3–5% of all neoplastic tumour lesions. The incidence has been increasing; there is a peak during the seventh decade of age.
In spite of advances in systemic treatment of RCC, primary complete tumour resection with tumour-free resection margins, as confirmed by histological investigation, is the only curative treatment in the T1/T2 stage. However, the reported 5-year survival of 86–96% and 60–67%, respectively, in this specific group of patients suggests a dependence on tumour stage according to the UICC classification. Interestingly, in T3b RCC, characterised by an additional tumour thrombus into IVC, which can be found in 5–10% of all patients with RCC, survival rate is substantially lower ranging from 36–59%.
There have been only approximately 200 cases with tumour lesions in horseshoe kidney(s) published in the literature.1–7
Combined with a doubled renal pelvis, it is extremely rare and only five cases have been published.8–12
IVC tumour thrombus of the advanced T3 RCC, requiring partial wall resection of IVC and patch plasty, was classified as stage II by STAEHLER, characterised by IVC tumour thrombus site below the influx segment of hepatic veins.13
Since tumour thrombus was partially adherent to the inner wall of IVC, it was impossible to avoid partial resection of the wall of the IVC to finally achieve R0 resection.
The rare cases of IVC-associated tumour lesions do not allow collecting extensive experiences. Therefore, the material with good vascular-surgical results and excellent handling in our hands, such as Dacron, is favoured for the patch plasty. Alternative materials can also be used, such as (heparin-coated) ePTFE, Vascuguard and autogenous vein.
In BOWER’s classification, an infiltrating RCC with tumour thrombus into IVC is a specific and separate entity of an IVC-associated tumour lesion.14
For surgical strategy according to KULAYAT, tumour expansion of level 2 (middle segment) was assessed (from confluence of renal veins to hepatic veins).15,16
In this context, complete resection of the tumour mass is the only efficient treatment of choice for cure and needs to be possibly achieved in the primary approach to avoid tumour fragmentation as happened. For curative intention, it needs to be included in planning surgery because, as mentioned above, 5–10% of all patients with RCC have already developed a continuous tumour infiltration of the anatomically neighboured IVC or even a tumour thrombus into IVC.17
In these cases, complete tumour resection comprising nephrectomy and resection of tumour-infiltrated parts or segments of the IVC or IVC-associated tumour thrombus has to be the basic aim of surgical treatment if there are no distant metastases. Since there are surgical options to achieve R0 resection status in case of an IVC tumour thrombus but no distant metastases, this seems to be of no significant disadvantage for patient’s prognosis,18–20
although there is no extensive experience on this subject. Again, the aim is, despite primarily advanced tumour growth, to achieve macro- and microscopically complete resection to provide the patient’s best outcome.
In addition, such complex and advanced findings are manageable by modern (vascular) surgical techniques and materials.15,16,21,22
A subsequent, secondary, additive (adjuvant) or alternative medication with tyrosine kinase inhibitors can be considered a further therapeutic option according to novel and recent reports.23,24
Despite the overall successful outcome, the initial treatment has to be critically discussed because of the only non-complete primary resection leading to remaining and residual tumour lesions in situ, including the fact that preoperatively IVC-associated tumour thrombus had not been diagnosed. This might have worsened the patient’s mid- or long-term prognosis.
Therefore, a diagnostically complete and conclusive preoperative imaging is essential for the assessment of tumour extension, surgical options and planning the specific approach as well as prognosis.
Preferably in advanced, complex and complicated tumour manifestations, diagnostic and primary treatment should be performed in a centre of excellence to achieve an optimal outcome by interdisciplinary cooperation of operative disciplines and adequate perioperative intensive care.
In conclusion, achieving R0 resection with a reasonable risk-benefit ratio for the patient, which should be the primary aim, can distinctly improve survival chances.
- This is the first report in literature of a rare case with co-incidence of RCC, IVC thrombus, horseshoe kidney and doubled right organ.
- In advanced tumour lesions of the kidney, aiming for resection is feasible and necessary for cure by primarily using an interdisciplinary cooperation in diagnostic work-up and treatment in a centre of excellence.
- To prevent any unexpected intraoperative events and needs, advanced surgical skills or special technical equipment (eg, off-pump cardiopulmonary bypass) are favoured, leading to the fact that further surgical disciplines, such as heart or vascular surgery, are included in planning and performing surgery as well as in postoperative care.
- Cure of RCC with IVC thrombus is possible by radical surgery, which includes complete tumour nephrectomy as well as resection of the tumour thrombus of the IVC. In case of thrombus adherence within the IVC or (rare) tumour infiltration of the IVC, resection or partial replacement of the IVC is necessary.