[Sonographic appearance of benign subcutaneous nodules--including color Doppler sonography]

OBJECTIVE

Color Doppler sonography is used to distinguish malignant from benign subcutaneous nodules because many malignant tumors show an increased number of vessels. But benign lesions, such as inflammatory epidermal cysts, pilomatricomas, palmoplantar fibromatoses show vascular flow signals. We analyze diagnostic factors for subcutaneous nodules on the basis of ultrasonographic appearance including color Doppler sonography.

METHODS

We evaluated with sonography 79 subcutaneous nodules in histopathologically proven cases.

RESULTS AND DISCUSSION

The diagnostic findings for 28 epidermal cysts were increased posterior echo(sensitivity 77%, specificity 90%). Vascular flow signals were seen in 7 cases(25%). The signals were seen from periphery to adjacent zone of the mass. They were accompanied by inflammatory granulation tissues histologically. The percentage of blood flow may be related to the percentage of "ruptured" epidermal cysts. Pilomatricomas (n = 9) had internal echogenic foci or Doppler flow signals, and no posterior enhancement (sensitivity 89%, specificity 78%). Seven pilomatricomas showed Doppler flow signals in the mass. The percentage of flow signals is explained by the degree of internal echogenic foci because remarkable calcium deposits producing posterior acoustic shadowing prevent us from flow signals. Palmoplantar fibromatoses (n = 5) were ill-defined margins and showed internal vascularity with no posterior enhancement (sensitivity 80%, specificity 94%).

CONCLUSION

More benign lesions showed vascular flow signals than reported previously. We have to diagnose subcutaneous nodules referring to not only color Doppler but also gray scale sonography.

Microvascular distribution and vascular endothelial growth factor expression in bovine cystic follicles

The aim of this study was to examine the distribution of microvessels in the theca and the expression of vascular endothelial growth factor (VEGF) in the theca and granulosa of cystic follicles. Paraffin sections of cystic follicles were stained with Bandeiraea simplicifolia-I (BS-I) to visualize the endothelial cells of microvessels. The other sections were immunostained with anti-VEGF antibody. The mRNA expression of VEGF in the theca interna of cystic and healthy follicle was determined by RT-PCR. In the theca interna, cystic follicles with granulosa cells had significantly greater microvessel number density (the number of microvessels per given field) and area (area occupied by microvessels per given area) than healthy follicles in various sizes (<3, 4-8, >9 mm). Loss of granulosa cells from cystic follicles resulted in a similar number density, but significantly smaller area of microvessels in the theca interna. There was no significant difference in the microvessel number density and area of the theca externa between the types of follicle. VEGF protein was expressed in the granulosa and theca interna of healthy and cystic follicles. These results demonstrate that cystic follicles have a highly developed vasculature network in the theca interna, especially in cystic follicles containing granulosa cells. It is also suggested that VEGF is highly expressed in the cystic follicle as well as healthy follicle, which may be associated with advanced vasculature and the accumulation of follicular fluid in cystic follicles.