Investig Clin Urol.  2016 Mar;57(2):100-105. 10.4111/icu.2016.57.2.100.

The role of Bosniak classification in malignant tumor diagnosis: A single institution experience

• Oh TH
• Seo IY

• KMID: 2363131
• DOI: http://doi.org/10.4111/icu.2016.57.2.100

Abstract

PURPOSE
To evaluate the clinical reliability of the Bosniak classification in Korea, and to identify independent predictors of malignancy in complicated renal cysts.
MATERIALS AND METHODS
We reviewed the records of 368 patients with renal cysts between January 2001 and December 2014; 14 patients were excluded, due to interobserver variability in Bosniak classification between the radiologist and urologist. Clinical characteristics and radiologic findings of malignant cystic masses were analyzed, retrospectively.
RESULTS
In 324 surgically excised lesions from patients (n=312) with renal cysts, the percentages of malignancy in the different Bosniak classifications were as follows: category I, 1.0% (1 of 103); II, 3.8% (2 of 53); IIF, 17.1% (7 of 41); III, 38.0% (27 of 71); and IV, 82.1% (46 of 56). Mean age and lesion size were 59.88+/-11.9 years (180 men, 144 women) and 5.47+/-3.51 cm, respectively. Univariate analysis identified hypertension (p=0.011), a history of smoking (p=0.038), and obesity (p=0.015) as the strongest risk factors of malignancy. In a study of Bosniak category III patients, hypertension (p=0.018), lesion size (p<0.001), and difference of Hounsfield Unit (HU) (p=0.027) were the strongest risk factors of malignancy. Multivariate analysis identified lesion size as the strongest potential predictor of malignancy, followed by hypertension and difference of HU.
CONCLUSIONS
Risk factors of malignancy in complicated renal cyst patients were not different from those published previously. In Bosniak category III lesions, hypertension and lesion size were the strongest predictors of malignancy. Characteristically, the lesion size was smaller than in benign complicated renal cysts, in contrast with other categories.

Keyword

Classification; Diagnostic imaging; Renal cell carcinoma

MeSH Terms

Adult
Aged
Carcinoma, Renal Cell/*diagnostic imaging/pathology
Diagnosis, Differential
Female
Humans
Kidney Diseases, Cystic/*diagnostic imaging/pathology/surgery
Kidney Neoplasms/*diagnostic imaging/pathology
Male
Middle Aged
Preoperative Care/methods
Reproducibility of Results
Retrospective Studies
Tomography, X-Ray Computed

Figure

• 

  Fig. 1 A 62-year-old woman with a category II cystic lesion (hyperdense cyst) in the left kidney. The patient underwent laparoscopic partial nephrectomy. The final pathological diagnosis is renal cell carcinoma (papillary renal cell carcinoma). (A) Unenhanced computed tomography (CT) scan shows small, smooth-walled, high-density left renal cyst. (B) CT scan after administration of contrast material shows no enhancement of the cyst.

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