I think this posting raises two issues:
1. The different versions of pathology compared to a gold standard.eg:
cytology, fine needle biopsies, frozen section, parrafin section with basic
stains, and the full gamut: parrafin sections with EM, immunocytochemistry
+/- flow cytometry and DNA analysis. The full gamut is generally considered
the "gold standard" (Im not aware of any studies comparing this with results
of long term follow-up)
There are studies looking at cytology (eg PAP. smears Ann Intern Med 2000
May 16;132(10):810-9 Accuracy of the Papanicolaou test in screening for and
follow-up of cervical cytologic abnormalities: a systematic review. Nanda K,
McCrory DC, Myers ER, Bastian LA, Hasselblad V, Hickey JD, Matchar DB
suggesting lowish senstivity 30-85% and reasonable specficity up to 100%)
fine needle biopsy (eg Cancer 2000 Apr 25;90(2):96-101
Invasive carcinoma in clinically suspicious breast masses diagnosed as
adenocarcinoma by fine-needle aspiration.
Chhieng DC, Fernandez G, Cangiarella JF, Cohen JM, Waisman J, Harris MN,
Roses DF, Shapiro RL, Symmans WF showing that specificity of FNA was high
(98% for invasive cancer), basically 100% if you also included DCIS)
So for cytology or FNA 2% error rate is reasonable.
2. The other issue is the different pathologists looking at the same
slides/data issue
a. the "difficult" diagnoses/subtypes
eg subtyping of lymphomas Ann Oncol 2000;11 Suppl 1:123-6 The effect of
Rituximab on patients with follicular and mantle-cell lymphoma. Swiss Group
for Clinical Cancer Research (SAKK).
Ghielmini M, Schmitz SF, Burki K, Pichert G, Betticher DC, Stupp R, Wernli
M, Lohri A, Schmitter D, Bertoni F, Cerny T
found 76/78 follicular lymphomas and 39/42 mantle cell lymphomas were
confirmed as such by central pathology review. Obviously no denominator here
to work out how many MCL & FL were "missed" by the outside pathologists.
Also work has been done by the Swedes in Soft Tissue sarcoma
b. the "routine" detection of malignancy vs benign diagnosis
ther only thing i can find on this is : : Arch Pathol Lab Med 1998
Apr;122(4):303-9 Amended reports in surgical pathology and implications for
diagnostic error detection and avoidance: a College of American Pathologists
Q-probes study of 1,667,547 accessioned cases in 359 laboratories.
Nakhleh RE, Zarbo RJ
As part of this program labs (347) prospectiobely collected amended reports
over 5 months. There were 3417 amendments: " ...The aggregate mean rate of
amended reports was 1.9 per 1000 cases (median, 1.5 per 1000 cases). Of
these, 19.2% were issued to correct patient identification errors, 38.7% to
change the originally issued final diagnosis, 15.6% to change a preliminary
written diagnosis, and 26.5% to change clinically significant information
other than the diagnosis. Most frequently, a request from a clinician to
review a case (20.5%) precipitated the error detection. "
So this suggests your 2% incorrect rate may not be too far from the real
world.
hope this helps
Brian Stein
Ashford Cancer Centre
[log in to unmask] voice: +61 8 8351 0211 fax: +61 8 8351 0255
"...in the field of observation chance favours the prepared mind."
----- Original Message -----
From: "Ted Harding" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, June 14, 2000 6:48 AM
Subject: histopathology error rates
> Hi Folks,
>
> I wonder if any of you can give me a ball-park figure for
> the error rate (False Positive and False Negative) in
> histopathological diagnosis (specifically cancer)?
>
> Would say 200 in 10,000 examinations (2 per cent) be
> considered at all high? Or even rather low?
>
> With thanks,
> Ted.
>
> --------------------------------------------------------------------
> E-Mail: (Ted Harding) <[log in to unmask]>
> Fax-to-email: +44 (0)870 284 7749
> Date: 13-Jun-00 Time: 22:18:02
> ------------------------------ XFMail ------------------------------
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