Renal Tumors in Adult Saudi Patients: A Review of 43 Cases

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1 Riyadh F. Talic, FRCS(Ed); Salah R. El Faqih, FRCS From the Division of Urology, Department of Surgery, King Khalid University Hospital, King Saud University, Riyadh. Address reprint requests and correspondence to Dr. Talic: Assistant Professor of Urology, Division of Urology, Department of Surgery, King Khalid University Hospital, P.O. Box 7805, Riyadh 11472, Saudi Arabia. Accepted for publication 9 April Received 23 December Seventy-nine patients with renal tumors were seen at King Khalid University Hospital (KKUH) over a 10-year period from 1985 through November In a retrospective study, we analyzed the records of 43 Saudi patients from all over the Kingdom; they represented 54% of all patients encountered. Fourteen percent of the patients had benign renal tumors in the form of angiomyolipoma and oncocytoma. Eighty-six percent of the patients had malignant renal tumors. The largest subset of 33 patients (76.7%) had renal cell carcinoma (RCC). The mean age of this group was 50.9, with a male-to-female ratio of 1.3:1. The duration of symptoms varied widely from a few months to a few years and the most common presenting symptom was loin pain. Only four patients were smokers and one patient had Von Hippel Lindau syndrome; no other risk factors could be identified in this group. This study shows a large percentage of angiomyolipoma among the tumors encountered. It also shows a high percentage of Saudi female patients in the RCC group; otherwise, the pattern and clinicopathological features resemble those presented in the international literature. Ann Saudi Med 1996;16(5): RF. Talic, SR. El Faqih, Renal Tumors in Adult Saudi Patients: A Review of 43 Cases. 1996; 16(5): Renal tumors include both benign and malignant new growths of the kidney. The majority are malignant, and renal cell carcinoma (RCC) is the most common histological type. 1 The incidence of renal tumors, and in particular of RCC, is unknown in Saudi Arabia. Epidemiological studies show that there is a global trend of a rising incidence of renal cancer, with little definite information on the underlying etiology. 2 The literature on renal tumors in adult Saudi patients is very scarce. We designed this retrospective study to look at the pattern, clinicopathologic features and possible underlying etiologic factors of various renal tumors in adult Saudi patients who presented to the Urology Unit at KKUH. Patients and Methods We reviewed the records of 79 patients with renal tumors who presented from 1986 through November 1995; 36 patients were non-saudi and were excluded from the final analysis because of their diverse ethnic origin. The charts of the remaining patients were analyzed for age, sex, mode of presentation and duration of symptoms. All patients underwent standard laboratory investigations, including complete blood count, serum electrolytes and creatinine, liver function tests and urinalysis. Radiological tests for diagnosis and staging included chest roentgenography, intravenous pyelogram or ultrasound of the kidneys, abdominal computerized tomography and bone scans. Selective renal angiography was carried out as indicated. Associated paraneoplastic syndromes, systemic illnesses and possible etiological factors were noted. The tumor laterality, polarity, size and histological typing were also recorded. Tumor staging of RCC was classified according to Flock's and Kadesky (1958). 1 Stage I: tumor confined to the kidney; Stage II: tumor invading perirenal fat but confined by Gerota's fascia; Stage III (a): tumor in renal vein or inferior vena cava; Stage III (b): tumor in lymph nodes; and Stage IV: involvement of adjacent organs or distant metastasis. Results A total of 43 Saudi patients presenting from various regions of the Kingdom were included in the study. Six patients had 10 benign renal tumors. Table 1 shows the patient characteristics of this group. Four patients presented with symptoms and signs similar to those with renal cancer. Patients 4 and 6 were diagnosed incidentally by ultrasound during investigation of postpartum bleeding and an attack of calculus cholecystitis, respectively. Patient No. 5 had a past history of epilepsy, and was noted to have features of tuberous sclerosis complex after she was diagnosed with bilateral angiomyolipoma; cerebral subependymal calcifications were noted on her computerized tomography scan of the brain. Preoperative diagnosis of angiomyolipoma was also achieved in patient No. 4, ultrasound and computerized tomography showing characteristic findings of angiomyolipoma in both kidneys. Left

2 nephrectomy was carried out on both these patients to remove bleeding tumors. The right kidney, with multiple small angiomyolipomas, is being followed up. The other four patients underwent radical nephrectomy for suspicion of malignancy. The benign nature of their tumors was confirmed on histological examination of the surgically excised kidneys. They remain well on follow-up; one patient (#3 in Table 1) developed a contralateral tumor with radiological features consistent with angiomyolipoma and is being followed up expectantly. Thirty-seven patients had malignant tumors. Two patients in this group had transitional cell carcinoma of the renal pelvis; both were males, 52 and 53 years old, and both presented with hematuria. Both patients underwent nephroureterectomy and were found to have G2PT2 and G2PT3 disease. Renal squamous cell carcinoma was encountered in two patients. A 50-year-old female and a 63-year-old male both presented with loin pain and on investigation were noted to have nonfunctioning kidneys. Intravenous pyelogram demonstrated a staghorn calculus in one patient and chronic pyelonephritic changes in the other, but no suggestion of malignancy. Simple nephrectomy was carried out and histological examination confirmed Stage I and II disease, respectively. The largest group (33 patients) had renal cell carcinoma; they included 19 male and 14 female patients (M:F ratio 1.3:1). Their ages ranged between 17-85, with a mean age of 50.9 ± The mean age for the male patients was 52.9 ± 18.9 (range 17-85), while the mean age for the female patients was 48.8 ± 6.3 (range 40-65). The duration of symptoms varied widely from a few months to a few years. Table 2 shows the various presentations of RCC. Only two patients (5%) presented with the so-called "classical triad," consisting of loin pain, hematuria and renal mass. Eleven tumors in 10 patients (30%) were diagnosed incidentally by ultrasound; the investigation was carried out for upper GI symptoms in six patients, ovarian cyst in one, lower urinary tract symptoms in one, as part of a routine health checkup in one and for screening purposes in one patient with Von Hippel Lindau syndrome initially presenting with blurred vision. This patient, on further investigation, was noted to have cerebellar hemangioblastoma and epididymal papillary cystadenoma. Seven of the incidentally diagnosed RCC were Stage I (64%), two were Stage II (18%) and two were Stage IV (18%). Nineteen patients with RCC had right-sided tumors, 13 had left-sided and one patient had bilateral synchronous RCC. These tumors were occupying the lower pole in 12 patients, the upper pole in 11 patient, and the middle pole in four patients. It was not specified in the rest, mainly due to the large size of the tumor extending beyond one pole. Table 3 show the various presentations by stage of renal cell carcinoma and average size of the tumors. Both patients with Stage III (a) had a tumor thrombus extending into the abdominal part of their inferior vena cava. Five of the patients with Stage IV had systemic metastasis; two patients had metastasis to the liver and the lung, one patient had brain metastasis, one patient had widespread bony deposits, and one patient had metastasis into the contralateral adrenal gland; the other two patients with Stage IV had involvement of a retroperitoneal cyst in one and infiltration into the posterior abdominal wall in the other. Table 1. Patients with benign renal tumors. Patient Age Sex Tumor 1 60 F Left angiomyolipoma 2 66 F Left simultaneous oncocytoma and angiomyolipoma 3 29 F Bilateral asynchronous angiomyolipoma 4 25 F Bilateral synchronous angiomyolipoma 5 29 F Bilateral synchronous angiomyolipoma 6 68 M Right angiomyolipoma

3 Table 2. Clinical features at presentation of RCC. Symptom (%) Loin pain 48 Hematuria 33 Mass 15 Weight loss 18 Fever 12 Malaise 9 Varicocele 3 Raised ESR 45 Anemia 6 Hypertension 12 Polycythemia 3 Table 3. RCC by stage and size. Stage No. of patients (%) Average size (cm) and range I 19 (58%) 7.9 (2.5-16) II 5 (15%) 8.5 (5.0-16) III 2 (6%) 9.7 (7.7-12) IV 7 (21%) 6.0 (4.2-11) Table 4. Presentation by stage of RCC. Source Stage I Stage II Stage III Stage IV Skinner et al % 7% 35% 25% Robson et al % 17% 31% 14% Best 15 46% 5.5% 19.5% 29% Present study 58% 15% 6% 21% All patients with Stages I-III of RCC were subjected to surgery. Radical nephrectomy was the standard procedure; the patient with bilateral RCC had bilateral partial nephrectomy. The patient with solitary metastasis into the adrenal gland had radical nephrectomy and contralateral adrenalectomy; the other patient with involvement of the retroperitoneal cysts had all the tumor mass successfully removed and the patient in Stage IV with infiltration of the posterior abdominal wall underwent exploration, but the tumor was deemed inoperable. Among tumors excised, 15 (44%) were clear cell, six (18%) granular cell, seven (20%) mixed cell type and the rest were undetermined. Only four patients gave a history of smoking; one patient had Von Hippel Lindau syndrome and no patients with chronic renal failure and acquired cystic kidney disease were encountered. Other dietary and environmental risk factors could not be studied from the retrospective data available. Discussion Renal tumors and, in particular, renal cell carcinoma are uncommon, accounting for 3% of adulthood malignancies in the West with variable international variation, 1,3 the incidence of RCC being high in Northern Europe and North America and lower in Asian countries. 3 The incidence in Saudi Arabia is not known; the various studies that looked at cancer pattern in Saudi Arabia either fail to mention renal tumors as an entity, or cite wide variations with relative frequency ranging between l-2.75%. 4-7 These differences may be due to variations in the incidence of the disease in the various provinces of Saudi Arabia; but may also be a reflection of the referral pattern of patients in the country. Among the various recognized benign renal tumors, we encountered only renal angiomyolipoma and oncocytoma. Renal angiomyolipoma accounted for 14% of the cases in our group, which is much higher than that reported in the literature of 1% of all surgically excised tumors. 8 Renal angiomyolipoma is known to affect females predominantly; 9 this is consistent with our findings where all patients but one were females. Fifty percent of all renal angiomyolipoma occur in tuberous sclerosis patients and up to 80% of patients with tuberous sclerosis exhibit

4 angiomyolipoma. 9,10 Only one of our patients had the stigmas of tuberous sclerosis complex. Renal angiomyolipoma in association with renal cell carcinoma has been described previously. 10,11 We did not come across such patients in our group, but one patient (No. 2 in Table 1) had unilateral simultaneous angiomyolipoma and oncocytoma, an association that has been described only once in the international literature. 12 Renal cell carcinoma is the most common solid renal tumor in adults, accounting for 80% of all renal tumors. 1,3 This is consistent with our findings. Half of our renal urothelial tumors were squamous cell carcinoma, which usually account for less than 15% of such tumors. 1 It is difficult to make any firm conclusions on this small number of patients, but this might be due to the high prevalence of renal calculus and chronic renal inflammatory diseases in our community. 1,3 The mean age and clinical presentation for our patients with renal cell carcinoma were consistent with that reported in the literature. 1,13-15 Loin pain or hematuria are the most common presenting symptoms in most series. 1,13,15,16 The most common presenting symptom in our patients was loin pain. Hematopoietic disturbances and endocrinopathies such as polycythemia, anemia and raised ESR have been reported in association with renal cell carcinoma. 1 We did encounter such patients (Table 2), but less frequently than expected. Presentation with paraneoplastic syndromes such as elevated parathyroid-like hormone manifesting as hypercalcemia or hepatic dysfunction is described with variable incidence. 1 No patient in our group presented as such. Renal cell carcinoma affect males predominantly. A male-to-female ratio of 2-3:1 is reported in many series Jamal et al. reported on a group of 30 patients with renal neoplasia; among those, there were 21 Saudi patients with a M:F ratio of 4:1. 16 This was not our observation, where the ratio of 1.3:1 suggests a higher occurrence in Saudi females. This observation is difficult to explain, but if confirmed in future reports, would indicate the necessity to investigate Saudi females closely for peculiar risk factors. Presentation by stage is compared to other series in Table 4. Seventy-three percent of patients with RCC in our group presented in Stage I and II and 21% presented in Stage IV. These results are compatible with other reports and suggest that there is no delay in the presentation or diagnosis of renal cancer in our patients similar to that seen with other urological cancers in Saudi Arabia ,17 Only 6% of the patients presented in Stage III, a much smaller but variable percentage in comparison to other studies. The incidence of patients with Stage III disease varies greatly in different reports and usually follows the referral pattern to tertiary centers that deal with these patients Renal tumors are being diagnosed as an incidental finding with increasing frequency in recent years. In accordance with other reports that show 20% to 30% prevalence of incidental RCC, 30% of our patients were diagnosed incidentally. All our patients were diagnosed with ultrasound examination, which is the most common imaging modality in detecting incidental renal tumors. 19 Recent advances, wider application of imaging diagnostic studies, and availability of medical services in Saudi Arabia may account for this prevalence in our group. The etiology of renal tumors is poorly understood. There are no definite risk factors, with the possible exception of tobacco smoking and acquired cystic disease of the kidney developing in patients with chronic renal failure on chronic dialysis. 2,3 The relation of all other environmental, dietary, and familial factors are not clear. 2 For this reason, it is difficult to establish, in a group of patients like ours, whether there are any particular risk factors peculiar to the Saudi population. We conclude that we encountered a high percentage of renal angiomyolipoma in our group of patients with renal tumors. An interesting finding was the lower incidence of tuberous sclerosis in our patients with renal angiomyolipoma. We also encountered a high percentage of female patients. Otherwise, renal tumors, in particular RCC, in Saudi patients resemble other groups in the literature with regard to their clinicopathological features. It is hoped that established tumor registries and future epidemiological studies will shed more light on the true incidence, patterns and possible risk factors that are relevant to our patients. References 1. dekernion JB. Renal tumors. Campbell's Urology, 5th edition, Philadelphia: W. B. Saunders, Katz DL, Zheng T, Holford TR, Flannery J. Time trends in the incidence of renal carcinoma: analysis of Connecticut tumor registry data, J Cancer 1994;58: Dayal H, Kinman J. Epidemiology of kidney cancer. Sem Onco 1983;10: Mahboubi E. Epidemiology of cancer in Saudi Arabia, Ann Saudi Med 1987;7: Khan A, Hussain NK, Al-Saigh A, Malatani T, Sheikha AA. Pattern of cancer at Asir Hospital, Abha, Saudi Arabia. Ann Saudi Med 1991;11: Ajarim DS. Cancer at King Khalid University Hospital, Riyadh. Ann Saudi Med 1992;12:76-82.

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