Metastatic melanoma of the skin: Surgical treatment

[Ultrasonographic findings validity in the identification of metastatic regional lymph nodes in patients with cutaneous melanoma]

BACKGROUND/AIM. Early identification of lymph node (LN) metastases has both therapeutic and prognostic significance in patients with cutaneous melanoma. Ultrasonographic (US) examination of LN morphological characteristics and US of LN morphological and vascular characteristics are diagnostic methods used in identification of regional LN metastases, thus rendering a base for lymphonododisection indication. The aim of this study was to determine validity of these two US diagnostic methods and eventual statistically significant difference between them. METHODS. The study included the two groups of the patients with clinical stage III melanoma. The group I included 31 patients followed up by the use of US of LN morphological characteristics due to the fact that US findings described them only. The group II included 30 patients in whom morphological and vascular LN characteristics were followed up. The patients of both groups were examined in the Institute for Radiology, Military Medical Academy using an ultrasonographic unit type Akuson Sequoia Model 2000. After that, therapeutic and elective radical disections were performed. Sensitivity, specificity and accuracy of US examination of LN were checked by histopathological examination.

RESULTS

The presence of LN metastases in the group I was suggested by LN enlargement and its extent, while in the group II it was suggested by the ratio of LN length and width in 83.3% of the patients, echogenicity of LN center in 76.7% of the patients, LN resistance index in 73.3% of the patients, pathologic LN vascularization in 86.7%, and pathologic intranodal arborization in 83.3% of the patients. In 67.7% of the patients in the group I and in 93.3% of the patients in the group II matastatic changes of LN were diagnosed by pathohistology. A difference between validities of the two groups was statistically significant (p < 0.05).

CONCLUSION

LN size without other US morphological and vascular characteristics of LN does not provide enough valid US finding for a reliable preoperative identification of LN with metastatic changes in patients with cutaneous melanoma.

Skin metastasis: a pathologist's perspective

Skin metastasis is defined as the spread of malignant cells from a primary malignancy to the skin. It is one manifestation of systemic spread of cancer. The tumor cells originate either from an internal malignancy or from a primary skin cancer. This study presents a literature review concerning these issues as well as this author's experience encountered throughout 19 years of surgical pathology and dermatopathology practice. Several conclusions are evident. Generally, skin metastases are encountered in 0.7-9% of all patients with cancer and as such the skin is an uncommon site of metastatic disease when compared to other organs. There is usually a long-time lag between the diagnosis of the primary malignancy and the recognition of the skin metastases. However, these metastases may be the first indication of the clinically silent visceral malignancies. The regional distribution of the skin metastasis, although not always predictable, is related to the location of the primary malignancy and the mechanism of metastatic spread. The relative frequency of skin metastasis correlates with the type of primary cancer, which occurs in each sex. For instance, lung and breast carcinomas are the most common primaries that send skin metastasis in men and women, respectively. The head and neck region and the anterior chest are the areas of greatest predilection in men. The anterior chest wall and the abdomen are the most commonly involved sites in women. Skin metastases usually appear as non-specific groups of discrete firm painless nodules that emerge rapidly without any explanation. They vary in size from so tiny as to be of 'miliary lesions' to as large as 'Hen's egg size'. Some skin metastasis may mimic specific dermatological conditions such as cutaneous cyst, dermatofibroma, pyogenic granuloma, hemangioma, papular eruptions, herpes zoster eruptions, rapidly infiltrating plaques, alopecic patches, cellulitis and erysipelas. Histologically, the skin metastases usually show features reminiscent of the primary malignancy, but with variable degrees of differentiation. Molecularly, skin metastasis is an organized, non-random and organ-selective process orchestrated by interaction among several heterogeneous molecules, which are largely unknown. Metastasis to the skin is often a pre-terminal event that heralds poor outcome.