DIFFICULTIES IN THE ULTRASOUND DIAGNOSIS OF LYMPH-NODE METASTASES IN CUTANEOUS MELANOMA WITH TUMOR-GROWTH

lymph node ultrasound examinations are performed during the follow-up of cutaneous melanoma in order to early recognise regional metastases. The excision of regional metastases is the only way to inhibit dissem inated metastasis in a certain percentage of cases. Lymph node ultraso und has a sensitivity of 95% in the diagnosis of pathological lymph no de changes. Sonographic findings normally show typical features of mal ignancy; only in some doubtful cases are further control examinations warranted over a period of 4-6 weeks. In violation of this rule, two c ases are presented with a delayed onset of metastases causing difficul ties in the diagnosis of malignant transformation. Four years after th e excision of a nodular melanoma with 0.8 mm tumor thickness at the ri ght lower leg, a suspicious lymph node change in the right groin was s onographically detected which did not fulfill all criteria of malignan cy. Control examinations over a period of 1 year found only a further growth of 3 mm. Excision after 1 1/2 years showed a lymph node metasta sis. The second case presented 9 years after the excision of a superfi cial spreading melanoma with 0.76 mm tumor thickness with a suspicious lymph node in the right axilla which similarly grew very slowly. The subsequent excision showed likewise a melanoma metastasis. A protracte d growth may occur in thin malignant melanomas with late development o f ultrasound features of malignancy. In doubtful cases an early biopsy is recommended.