Venous thromboses of upper limbs are more frequently associated with occult cancer as compared with those of lower limbs.

Three hundred and forty-three consecutive patients with deep vein thrombosis (DVT) were investigated for the possible presence of occult or undiagnosed cancer, of whom 305 patients had DVT of the lower limbs whereas 38 had DVT of the upper limbs. Cancer was diagnosed during a 12-month follow-up in nine patients with DVT of the upper limbs (23.7%) and in 34 patients with DVT of the lower limbs (11.1%). The difference was statistically significant. Furthermore, it was shown that the majority of cancers (seven of nine) in the case of DVT of the upper limbs were discovered during the first week of hospital admission. In contrast, in the case of DVT of lower limbs, only eight of 34 cancers were discovered during the initial investigation. Lung cancer and lymphomas represented the majority of cancers associated with upper limb venous thrombosis (seven of nine). In the case of DVT of the lower limbs, cancers were heterogeneous; however, 12 of 34 were cancers of the colon or prostate.