Figure 1
Teaching Case
SectionUroradiology & genital male imaging
Case TypeClinical Cases
Authors
Athina C. Tsili1, Aikaterini Lentoudi1, Maria I. Argyropoulou1 Efi Mpalasi2, Vasiliki Malamou-Mitsi2, Konstantinos Tsampoulas1
1Department of Clinical Radiology
2Department of Pathology
University Hospital of Ioannina, Greece.
Connected authors
70 years, male
A 70-year-old man with a history of chronic renal failure was referred for an incidentally found non-cystic left renal mass, sonographically. CT examination revealed the presence of a heterogeneously enhancing renal tumour and retroperitoneal lymphadenopathy.
Unclassified renal cell carcinoma
conventional RCC
transitional cell carcinoma of the pelvicaliceal system with invasion of renal parenchyma
CT examination showed an expansile, left upper pole renal mass, with ill-defined margins (Figs. 1, 2, 3). The lesion was inhomogeneous, with a CT density similar to that of normal renal parenchyma on plain images (Fig. 1). A small calcification was revealed within the tumour. The mass showed moderate, heterogeneous enhancement after contrast-material administration (Fig. 2), causing amputation and erosion of the upper and middle calyces (Fig. 3). The CT findings were strongly suggestive of renal malignancy. Perinephric stranding (Figs. 2a, b) in the vicinity of the mass indicated spread of the tumoural tissue. The inferior vena cava and the left renal vein were patent. Retroperitoneal lymphadenopathy (Fig. 2c) was found to coexist, confirming the diagnosis of malignancy.
Left radical nephrectomy showed a high-grade (grade IV) unclassified renal cell carcinoma (Fig. 4), with invasion of the perinephric fat (stage pT3a).
Left radical nephrectomy showed a high-grade (grade IV) unclassified renal cell carcinoma (Fig. 4), with invasion of the perinephric fat (stage pT3a).
Background
Renal cell carcinoma (RCC) represents 1-3% of all malignancies in the adult population, representing a significant cause of morbidity and mortality [1, 2]. According to 2004 WHO classification RCC includes five main histological subtypes, that is conventional (clear cell), chromophil (papillary), chromophobe, collecting duct and unclassified category [3-5].
Unclassified renal cell carcinoma (URCC) is a category that does not fit into the other histological types of RCC, based on histological and/or genetic characteristics [6-11]. This rare variant accounts for 3-5% of RCCs [6-11]. Zisman et al. in a study of 31 URCCs reported an aggressive biologic behavior and a poor prognosis for unclassified variety of RCC [6]. More specifically, unclassified disease was associated with larger tumour size, increased risk of adrenal gland involvement, direct invasion to adjacent organs, bone, regional and nonregional lymph node metastases and sarcomatoid differentiation [6]. The median survival time for these patients was reported at 4.3 months [6]. In an analysis of 85 cases of URCCs, Karakiewich et al. reported a mortality rate 4.7 times higher than for patients with conventional RCC [7]. Crispen et al. reported that URCCs are more likely to have regional lymph node metastases, higher tumour grade, tumor necrosis and sarcomatoid differentiation when compared to clear cell RCC, although no statistically significant difference in patient outcome was noted [8]. The above characteristics were met in this case. Our patient presented with a high grade URCC and advanced stage at diagnosis.
Imaging Perspectives
Computed tomography is considered the examination of choice for the detection and staging of RCC [1, 2, 12-15]. Multidetector CT with the improvement of spatial resolution and the ability to obtain multiplanar and three-dimensional reconstructions devoid of artefacts resulted in improvement in the preoperative evaluation of RCC [1, 2, 12-15]. Tumour size, lesion contour, presence or absence of calcification and/or necrosis, mass homogeneity or heterogeneity, pattern and degree of contrast enhancement represent important imaging features, which a radiologist must consider when interpreting a CT study [12]. The presence and pattern of enhancement remains a significant predictor of diagnosis and aggressiveness of renal cell carcinoma. More specifically, a strong and heterogeneous enhancement, as seen and in this case is more likely to represent an aggressive disease, whereas peripherally enhancing lesions are more likely to represent a less aggressive behavior [12].
Renal cell carcinoma (RCC) represents 1-3% of all malignancies in the adult population, representing a significant cause of morbidity and mortality [1, 2]. According to 2004 WHO classification RCC includes five main histological subtypes, that is conventional (clear cell), chromophil (papillary), chromophobe, collecting duct and unclassified category [3-5].
Unclassified renal cell carcinoma (URCC) is a category that does not fit into the other histological types of RCC, based on histological and/or genetic characteristics [6-11]. This rare variant accounts for 3-5% of RCCs [6-11]. Zisman et al. in a study of 31 URCCs reported an aggressive biologic behavior and a poor prognosis for unclassified variety of RCC [6]. More specifically, unclassified disease was associated with larger tumour size, increased risk of adrenal gland involvement, direct invasion to adjacent organs, bone, regional and nonregional lymph node metastases and sarcomatoid differentiation [6]. The median survival time for these patients was reported at 4.3 months [6]. In an analysis of 85 cases of URCCs, Karakiewich et al. reported a mortality rate 4.7 times higher than for patients with conventional RCC [7]. Crispen et al. reported that URCCs are more likely to have regional lymph node metastases, higher tumour grade, tumor necrosis and sarcomatoid differentiation when compared to clear cell RCC, although no statistically significant difference in patient outcome was noted [8]. The above characteristics were met in this case. Our patient presented with a high grade URCC and advanced stage at diagnosis.
Imaging Perspectives
Computed tomography is considered the examination of choice for the detection and staging of RCC [1, 2, 12-15]. Multidetector CT with the improvement of spatial resolution and the ability to obtain multiplanar and three-dimensional reconstructions devoid of artefacts resulted in improvement in the preoperative evaluation of RCC [1, 2, 12-15]. Tumour size, lesion contour, presence or absence of calcification and/or necrosis, mass homogeneity or heterogeneity, pattern and degree of contrast enhancement represent important imaging features, which a radiologist must consider when interpreting a CT study [12]. The presence and pattern of enhancement remains a significant predictor of diagnosis and aggressiveness of renal cell carcinoma. More specifically, a strong and heterogeneous enhancement, as seen and in this case is more likely to represent an aggressive disease, whereas peripherally enhancing lesions are more likely to represent a less aggressive behavior [12].
References
[1] Sheth S, Scatarige JC, Horton KM, et al. (2001) Current concepts in the diagnosis and management of renal cell carcinoma: role of multidetector CT and three-dimensional CT. Radiographics 21:S237-S254 (PMID: 11598260)
[2] Catalano C, Fraioli F, Laghi A, et al (2003) High-resolution multidetector CT in the preoperative evaluation of patients with renal cell carcinoma. AJR 180:1271-1277 (PMID: 12704036)
[3] Prasad SR, Humfrey PA, Catena JR, et al (2006) Common and uncommon histologic subtypes of renal cell carcinoma: imaging spectrum with pathologic correlation. Radiographics 26:1795-1810 (PMID: 17102051)
[4] Dai JR, Zhang LY, Zhang J, et al (2010) Differentiation of subtypes of renal cell carcinoma by double- phase helical computed tomography. Zhonghua Yi Xue Za Zhi 90:2177-81 (PMID: 21029656)
[5] Kim JK, Kim TK, Ahn HJ, et al (2002) Differentiation of subtypes of renal cell carcinoma on helical CT scans. AJR 178:1499-1506 (PMID: 12034628)
[6] Zisman A, Chao DH, Pantuck AJ, et al (2002) Unclassified renal cell carcinoma: clinical features and prognostic impact of a new histological subtype. J Urol 168:950-5 (PMID: 12187197)
[7] Karakiewich PI, Hutterer GC, Trinh QD, et al (2007) Unclassified renal cell carcinoma: an analysis of 85 cases. BJU 100:802-808 (PMID: 17822461)
[8] Crispen PL, Tabidian MR, Allmer C, et al (2010) Unclassified renal cell carcinoma: impact on survival following nephrectomy. Urology 76:580-6 (PMID: 20223503)
[9] Ljungberg B, Alamdari FI, Stenling R, Ross G (1999) Prognostic significance of the Heidelberg classification of renal cell carcinoma. Eur Urol 36:565-569 (PMID: 10559609)
[10] Amin MB, Amin MB, Tamboli P, et al (2002) Prognostic impact of histologic subtyping of adult renal epithelial neoplasms: an experience of 405 cases. Am J Surg Pathol 26:281-291 (PMID: 11859199)
[11] Ficarra V, Schips L, Guille F, et al (2005) Multiinstitutional European validation of the 2002 TNM staging system in conventional and papillary localized renal cell carcinoma. Cancer 104:968-974 (PMID: 16007683)
[12] Zhang J, Lefkowitz RA, Ishill NM, et al (2007) Solid renal cortical tumors: differentiation with CT. Radiology 244:494-504 (PMID: 17641370)
[13] Hallscheidt PJ, Bock M, Riedasch G, et al (2004) Diagnostic accuracy of staging renal cell carcinomas using multidetector-row computed tomography and magnetic resonance imaging. A prospective study with histopathologic correlation. J Comput Assist Tomogr 28:333-339 (PMID: 15100536)
[14] Dighe M, Takayama T, Bush Jr WH (2007) Preoperative planning for renal cell carcinoma – Benefits of 64-Slice CT imaging. International Braz J Urol 33:305-312 (PMID: 17626646)
[15] Hallscheidt P, Wagener N, Gholipour F, et al (2006) Multislice computed tomography in planning nephron-sparing surgery in a prospective study with 76 patients: comparison of radiological and histopathological findings in the infiltration of renal structures. J Comput Assist Tomogr 30:869-874 (PMID: 17082687)
Case information
| URL: | https://eurorad.org/case/9599 |
| DOI: | 10.1594/EURORAD/CASE.9599 |
| ISSN: | 1563-4086 |
Figure 1
Tsili A, Department of Clinical Radiology, Greece
Figure 3
Tsili A., Department of Clinical Radiology,Greece
