Plantar vein thrombosis: a rare differential diagnosis in patients with plantar pain

A female, 42-year-old, smoking patient with previous history of thrombotic thrombocytopenic purpura, undergoing corticosteroid and plasmapheresis therapy was admitted to the hospital presenting with important pain in the plantar region of her right foot, with difficulty in ambulation starting about one week ago. The patient denied the occurrence of any trauma, previous surgery or recent travel. At physical examination, only hyperalgesia was observed at palpation. Magnetic resonance imaging (MRI) of the right foot demonstrated thickening and failure in filling in the whole extent of the lateral plantar vein associated with perivenular enhancement and edema of adjacent structures, suggesting the presence of plantar vein thrombosis (Figure 1). Supplementary ultrasonography showed the presence of hypoechogenic material within de lateral plantar vein in association with ectasia and non-compressibility of the vessel, as well as absence of flow at Doppler study – findings which corroborated the initial hypothesis (Figure 2). The patient was discharged with recommendations for rest and treatment with nonsteroidal antiinflammatory drugs (NSAIDs), and presented with symptoms improvement at clinical follow-up. Plantar vein thrombosis (PVT) is a rare condition characterized by development of an intraluminal thrombus in plantar veins, with less than 100 cases published in the literature. It preferentially affects women of mean age 58.2 years. Generally, the lateral plantar vein is most affected (in 96% of cases), followed by the middle plantar vein (in 41%). Several causal factors are speculated, among them traumas, paraneoplastic syndromes, postoperative conditions, thrombophilias, use of contraceptive drugs, immobilization and HIV infection. However, most cases are classified as being idiopathic.