[Morphological characteristics of metastasis of undifferentiated cancer into the cervical lymph nodes without previous detection of the site of the primary tumor].

Morphological examination of the lymph nodes with undifferentiated carcinoma metastasis from 52 patients without an identified primary tumour at the time of biopsy has been performed. Metastases are subdivided morphologically into large-cell, spindle-cell and small-cell. Morphological criteria of differential diagnosis are given. The source of metastases was further determined in 42 patients, this being mainly the tumours of organs of the neck and head, predominantly the nasopharynx. Morphological features of undifferentiated carcinoma metastasis may be sometimes helpful in the determination of the primary tumour. Thus, metastasis of undifferentiated nasopharynx carcinoma has rather specific structure.