title: A case of multiple myeloma presenting as a distal renal tubular acidosis with extensive bilateral nephrolithiasis.
abstract: BACKGROUND
  At the time of diagnosis, Multiple Myeloma is commonly associated with renal impairment. Renal tubular acidosis without overt renal insufficiency is an uncommon disease presentation of myeloma. Among tubular acidosis types, isolated renal tubular acidosis is a very unusual presentation of multiple myeloma.
  
  
  METHODS
  We present a 55 years old female who presented with lower limb weakness due to persistent hypokalaemia caused by distal renal tubular acidosis. On further investigation of her anaemia with high erythrocyte sedimentation rate, we diagnosed IgG myeloma.
  
  
  CONCLUSIONS
  Isolated distal renal tubular acidosis is a rare presentation of multiple myeloma. In the absence of hypercalciuria and demonstrable light chain excretion in urine, we assumed that the distal renal tubular acidosis could have been caused by monoclonal hypergammaglobulinaemic state of multiple myeloma.
authors.affiliation: General Medicine, National Hospital, Colombo, Sri Lanka.
authors.forename: Chathuranga Lakmal
authors.initials: CL
authors.lastname: Fonseka
authors.affiliation: General Medicine, National Hospital, Colombo, Sri Lanka.
authors.forename: Sampath Rukshani
authors.initials: SR
authors.lastname: Galappaththi
authors.affiliation: General Medicine, National Hospital, Colombo, Sri Lanka.
authors.forename: Jeewandarage Dhanushka
authors.initials: JD
authors.lastname: Karunarathna
authors.affiliation: General Medicine, National Hospital, Colombo, Sri Lanka.
authors.forename: Dayakshi Dushyantha Kumarihami
authors.initials: DD
authors.lastname: Abeyaratne
authors.affiliation: General Medicine, National Hospital, Colombo, Sri Lanka.
authors.forename: Nirmali
authors.initials: N
authors.lastname: Tissera
keywords: Distal renal tubular acidosis; Multiple Myeloma; Nephrolithiasis