Exfoliative cytology of nonlymphoreticular neoplasms in children.

During the last 11 years, 144 nonlymphoreticular neoplasms were diagnosed in exfoliative cytology specimens obtained from patients younger than 17 years of age. Neuroblastoma was the single most common neoplasm (30 cases). Other categories of malignant neoplasms were primary bone tumors (30 cases), soft-tissue sarcomas (25 cases), brain tumors (25 cases) and epithelial neoplasms (7 cases). Of the 780 cytologic specimens, 335 were positive for malignant cells. Serous effusions provided most of the positive specimens from patients with neuroblastoma, germ-cell tumors and bone sarcomas. Exfoliated cells of metastatic embryonal rhabdomyosarcoma and primary brain tumors were detected most often in cerebrospinal fluid specimens. A most unusual presentation of an immature teratoma of the ovary is described in some detail. Despite the rarity of pediatric neoplasms, certain specific or suggestive cytologic features were recognized, including rosette formation of neuroblasts, nuclear notching of myoblasts, pleomorphism of osteoblasts and fibrillar processes of glial elements.