a 56-year - old man presented with a 12-month history of tingling ulcers on both feet ( figure 1a ) . he was otherwise well . on examination there were ulcers on both feet , 11.5 cm in diameter with a macerated edge . skin - colored to red - brown papules were noted on both knees ( figure 1b ) as well as irregular red circles on both calves . skin biopsies taken from knee papules and red circles on the lower leg showed extravascular eosinophilic deposits in the dermis ( figure 1c ) , which stained positive with pas , igm ( figure 1d ) and kappa stains , but negative with congo red . investigations are summarised here : serum kappa free chains , 85.9 mg / l ( normal 3.319.4 mg / l ) ; serum lambda free chains , 17 mg / l ( normal 7.726.3 mg / l ) ; serum free kappa chains /free - lambda chains ratio , 5.05 ( normal 0.261.65 ) ; serum electrophoresis , elevated ig m gradient ; serum immunofixation , monoclonal ig m / kappa - type immunoglobulin ; urine immunofixation , monoclonal kappa - free chain ; bone marrow microscopy , infiltrate of lymphoplasmocytic cells ( 15% ) ( most cd20 and cd138 positive ) with preferential expression for igm . the cutaneous manifestations of waldenstrm macroglobulinaemia have been classified as either infiltration by neoplastic cells or those related to the paraproteinaemia , such as immunoglobulin deposition , cryoglobulinaemia or blood hyperviscosity . approximately 5% of patients with waldenstrm macroglobulinaemia develop cutaneous manifestations , with neoplastic infiltration being the least common . prognosis does not appear to be influenced by the presence or absence of cutaneous disease . the patient presented with a burning red face which was initially diagnosed as rosacea but with time the more typical purple infiltration developed . macroglobulinaemia the neuropathy is typically sensorimotor , initially with paraesthesias and numbness in the feet and hands . the possible mechanisms in waldenstrm macroglobulinaemia include microangiopathy , direct infiltration of nerves , endoneural deposition of igm protein or amyloidosis , hyperviscosity or immunoglobulin deposit in blood vessels . the tingling ulcers in our patient are probably an example of this and , although biopsies were not taken from the ulcers , may have been due to igm deposition given he also had macroglobulinaemia cutis . there has been only one other case reported , to our knowledge , of ulcers on the sides of the feet . these developed in areas of hyperkeratosis and were associated with dysaesthesia and a burning sensation . however , the biopsy showed a leukocytoclastic vasculitis with a neutrophilic infiltrate . another report described igm dermal deposits that presented as painful hyperkeratotic papules on the soles of the feet that were not ulcerated . storage papules , also known as macroglobulinaemia cutis , are rare but well described and are usually found on the knees or other extensor surfaces . they are usually skin - coloured , red - brown or translucent , and may be umbilicated , crusted or haemorrhagic . after five cycles the lower limb ulceration and neurological symptoms had resolved , although the blood igm level did not change . waldenstrm macroglobulinaemia is a low - grade lymphoplasmacytoid lymphoma that usually presents with nonspecific systemic symptoms , but cutaneous changes may be the initial manifestation and hence may present first to a dermatologist . although our patient presented with tingling ulcers , the diagnosis was reached after skin biopsy from knee papules demonstrated dermal immunoglobulin deposition .