Clinical and sonographic findings in carcinoma of the penis

This study was performed to assess the accuracy of high-resolution sonography in measuring penile carcinoma.

Sonography was performed using a 7.5-MHz linear-array transducer in 59 patients with penile carcinoma. The sonographic measurement of tumor extent was compared with clinical and pathologic measurements. The tumor extent measured by gross pathologic evaluation on cut sections of the fresh penectomy specimen was used as the definitive standard. The echogenicity of the tumor was compared with that of the surrounding normal penile tissue to classify the tumor as hyperechoic, hypoechoic, or of mixed echogenicity (containing both hyperechoic and hypoechoic elements). We evaluated the relationship between the echogenicity of the tumor and both tumor morphology (exophytic or infiltrative) and tumor grade as determined on pathologic examination.

The overall mean difference +/- standard deviation in the tumor extent between clinical and gross pathologic evaluation was 3.9 +/- 5.3 mm (range, 1-9 mm), whereas the overall mean difference between sonographic and gross pathologic evaluation was 1.2 +/- 1.7 mm (range, 1-7 mm). As determined with reference to the gross pathologic extent, the error in measuring the extent on clinical examination was significantly greater than the error on sonography (p < 0.001). Lesions involving the glans alone were more often underestimated by clinical examination than were lesions involving the shaft (with or without glanular involvement). The error in measuring the extent of tumor by sonography was not related to the site of the tumor. The tumor was hyperechoic in 21 cases (36%), hypoechoic in 28 cases (47%), and of mixed echogenicity in 10 cases (17%). There was no significant association between echogenicity and tumor morphology or grade.

Sonography gives a more accurate estimate of penile tumor extent than does physical examination. Routine use of sonography for such measurements should enable preservation of more of the penis.