[Thermographico-histologic study of the lymph drainage areas in malignant melanoma]

In an investigation including 176 patients with malignant melanoma (MM) of the skin, the preoperative infrared telethermograms (IR-TT) obtained from the draining lymph node area were compared with the clinical and histologic data on lymph nodes removed by dissection. In 19 out of 92 cases with high-risk MM subjected to primary tumor excision and draining lymph node dissection, metastatic involvement of one or more lymph nodes was found histologically. In 18 of 19 cases (= 95%) with metastatic spread of MM, there was a considerable degree of hyperthermic radiation in the respective axillary or inguinal area. On palpation, only 13 of 19 patients (= 68%) showed conspicuous lymph node enlargement. The histologic sections of the lymph nodes of the above 18 patients with both regional spread of MM and hyperthermia were reexamined in order to compare the extent of tumor involvement with the q-classification of IR-TT. There was a remarkable correlation between an increase in the number of macrometastases (and conversely, a drop in the number of micrometastases) and the grades of regional hyperthermia.