title: An objective measure of growth rate using partial biopsy specimens of melanomas that were initially misdiagnosed.
abstract: BACKGROUND
  To calculate melanoma rate of growth (ROG), previous studies have relied on subjective patient recall to estimate time delay to diagnosis.
  
  
  OBJECTIVE
  To objectively calculate ROG by measuring the rate of increase in melanoma thickness between 2 sequential biopsy specimens over time.
  
  
  METHODS
  This was a retrospective review of 51 melanomas in which pathologic misdiagnosis of a partial biopsy specimen caused a delay before referral and excisional biopsy between January 1998 and January 2013. ROG was calculated as rate of increase in tumor thickness between biopsy specimens.
  
  
  RESULTS
  The median delay between the 2 biopsy specimens was 27 months (range, 3-89 months). Biopsy specimens of melanomas that were obtained initially in their in situ phase were thinner at excision compared to those that were first obtained as invasive tumors (median, 0.7 vs. 3.2 mm; P<.01) and had a lower ROG (median, 0.04 vs. 0.11 mm/month; P=.05). Faster growth was associated with increased tumor thickness, higher mitotic rate, symptoms, elevation, and amelanosis.
  
  
  CONCLUSIONS
  Partial biopsy specimens may not be representative of deepest tumor thickness.
  
  
  CONCLUSIONS
  We have demonstrated an objective measure of melanoma growth rate using sequential biopsy specimens. The correlation between faster growth and aggressive tumor features supports what others have found and validates the historical measure of growth rate as a reliable clinical marker.
authors: Victorian Melanoma Service, Alfred Hospital, Melbourne, Australia. Electronic address: drmatthewlin@gmail.com.
authors: Matthew J
authors: MJ
authors: Lin
authors: Victorian Melanoma Service, Alfred Hospital, Melbourne, Australia; Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.
authors: Victoria
authors: V
authors: Mar
authors: Victorian Melanoma Service, Alfred Hospital, Melbourne, Australia; Department of Anatomical Pathology, Alfred Hospital, Melbourne, Australia.
authors: Catriona
authors: C
authors: McLean
authors: Victorian Melanoma Service, Alfred Hospital, Melbourne, Australia.
authors: John W
authors: JW
authors: Kelly
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle; D002278:Carcinoma in Situ / Q000473:pathology*; D015331:Cohort Studies; D016208:Databases, Factual; D003951:Diagnostic Errors; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D012017:Referral and Consultation / Q000639:trends; D012189:Retrospective Studies; D018570:Risk Assessment; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology*; D018709:Statistics, Nonparametric; D013997:Time Factors; D047368:Tumor Burden
keywords: melanoma; misdiagnosis; rate of growth; tumor kinetics