title: Obesity-associated lymphoedematous mucinosis.
abstract: BACKGROUND
  Mucin deposition on the shins is considered as an indicator of pretibial myxoedema, which is typically seen in patients with Graves' disease.
  
  
  OBJECTIVE
  The purpose of this study was to report the clinical and histopathological features of a group of patients with pretibial mucinosis in the absence of thyroid disease.
  
  
  METHODS
  Five patients are included in this series and studied both clinically and histologically and compared with similar cases in the literature.
  
  
  RESULTS
  All patients were middle aged or elderly. Four patients were women. They were characterized clinically by morbid obesity and bilateral lower extremity pitting oedema sparing the feet. Semitranslucent papules and/or nodules and sometimes vesicles were found on the shins. Characteristic histological features include (i) hyperorthokeratosis with epidermal atrophy and effacement of the rete ridge pattern, (ii) oedema in the papillary and upper part of the reticular dermis with mucin deposition stained positively with alcian blue and colloidal iron, (iii) angioplasia in the upper part of dermis with upward-running, increased and thickened capillary vessels and (iv) variable fibrosis in the reticular dermis with separation of collagen bundles and increased stellate or linear fibroblasts. A hypocaloric diet was given in two cases, and an important weight loss was observed, which was accompanied by a marked improvement of the pretibial mucinosis.
  
  
  CONCLUSIONS
  Pretibial mucinosis is a histological feature associated with morbid obesity and lymphoedematous features of the legs that should be distinguished from true pretibial myxoedema. The term of 'obesity-associated lymphoedematous mucinosis' seems to be appropriate for this condition.
authors.affiliation: Section of Dermatology, DISEM, University of Genoa, Genoa, Italy. franco.rongioletti@unige.it
authors.forename: Franco
authors.initials: F
authors.lastname: Rongioletti
authors.forename: Pietro
authors.initials: P
authors.lastname: Donati
authors.forename: Ada
authors.initials: A
authors.lastname: Amantea
authors.forename: Gerardo
authors.initials: G
authors.lastname: Ferrara
authors.forename: Martina
authors.initials: M
authors.lastname: Montinari
authors.forename: Francesca
authors.initials: F
authors.lastname: Santoro
authors.forename: Aurora
authors.initials: A
authors.lastname: Parodi
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007866:Leg / Q000473:pathology*; D007868:Leg Dermatoses / Q000473:pathology; D008209:Lymphedema / Q000209:etiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017520:Mucinoses / Q000209:etiology* / Q000473:pathology; D009230:Myxedema / Q000473:pathology; D009767:Obesity, Morbid / Q000150:complications* / Q000473:pathology