A flow cytometric analysis of 23 carcinoid tumors.

Twenty-three carcinoid tumors were investigated from paraffin-embedded tissue with flow cytometry (FCM) in order to correlate the DNA ploidy with clinical variables. DNA aneuploidy was found in ten tumors (45%) and one tumor was classified as tetraploid. Diurnal urinary excretion of 5-hydroxy indolic acetic acid (5-HIAA) was known to be elevated in seven of eight diploid tumors and in four of seven aneuploid carcinoids with distant metastases. Six (55%) of the diploid tumors had not given rise to metastases at the time of diagnosis, compared with three (30%) of the aneuploid tumors. Six of seven patients with an aneuploid tumor and three of five patients with a diploid tumor, observed for at least 10 years, died of the disease. It was concluded that, unlike in earlier studies with static DNA cytometry, DNA aneuploidy is common in human carcinoid tumors and may occur in tumors secreting biogenic amines.