The need, impact, importance and disagreement rate for second opinion pathology referrals has been a constant topic of discussion for many years.  These second opinions generally come in two flavors.  The first is a consultation of a particularly challenging case by a pathologist or clinician.  Patients can also initiate these consults if they are uncomfortable with a diagnosis.  The second flavor is the review of pathology diagnoses of patients now seeking treatment at a new institution who were originally diagnosed by an outside pathologist from the referring institution.  The popular press contains many stories about misdiagnoses in patients and mismanagement until second opinion/expert review identified a problem with the original pathology review.  The pathology literature contains dozens of studies and meta-analyses looking at disagreement rates from referral centers looking at "us versus them", working off the notion that the second opinion/referral/expert diagnosis is "the right one", "the gold standard" or represents "the absolute truth" for treatment, management, outcomes measurements and classification for subsequent tissue/molecular studies.  In a similar, but distinctly different scenario, pathologists, clinicians and patients can each seek a "second opinion" or consultation on challenging cases or diagnoses they are uncomfortable with.

Here is the typical scenario and how this works:

"Most people never consider the possibility of getting a second opinion on the pathology report from which the diagnosis was made, but the entire plan of treatment depends on what kind of cancer you have and how far it has spread, both of which usually depend in part or whole on the pathologists interpretation of the biopsy or surgical specimen. Changes in the interpretation of the pathology can dramatically change both the treatment and the prognosis.

At the same time, most patients probably do not need a second pathology opinion. There are some common sense cues that can let you know if it might make sense. I think that if you have a really rare cancer, it is always advisable to get a second pathology opinion.

If your pathology report doesn't give a definite diagnosis, a second opinion is probably in order.

Your hospital/group name here Pathology Department has the expertise to diagnose and classify all types of cancer, which helps oncologists choose the most effective treatment method for their patients. We provide second opinion evaluation of tissue samples submitted by physicians and pathologists for patients outside Your health care system name here.

We have experts in a wide range of cancer subspecialties, including:

• Breast
• Dermatopathology
• Gastrointestinal
• Genitourinary
• Gynecological
• Head and neck
• Neuropathology
• Bone and soft tissue
• Thoracic

Fees must be paid at time of the review. Many insurance carriers will reimburse the costs of second opinion consultations. If payment is a problem, we can work with you. Follow-up reviews are payable separately. Please remember that our service is for pathology second opinions only. We cannot discuss or recommend treatment options."

Consultations in pathology are an integral and routine part of daily practice.  Except for the pathologist or the group that claims "I/we don't send anything out".  That person/group may not but informed patients/clinicians will.  As a resident I was warned if you don't show cases to others or get consults from external sources you are doing your patients and yourself a disservice.  

Institutions/individuals who provide second opinion reads as part of or exclusively as their practice of pathology have from time to time, in many subspecialties made claims about disagreement rates that justify the practice for risk management and appropriate patient management with published disagreement rates from 2-5%, depending on the specimen tissue source or part type.  There is also the issue of defining what constitutes a "disagreement", although most studies cite a difference that would alter prognosis or treatment.

Teleconsultations using whole slide imaging, as frequent readers know, I think are one of the many use cases/applications for digital pathology.  Mitigating slide handling issues, improving turn around time, retaining original glass slides onsite, reviewing cases with your consultant in real-time and education/training from external review at another site.

A recent paper shows that, in general, there is a very high level of agreement among pathologists for secondary review of pathology for referral patients, in this study, a rate of 99.4% agreeement.  While small (0.6%), the diagnostic differences may be highly clinically significant, arguing that secondary review of pathology materials should be standard of care.  This high agreement rate should allay concerns of patients and clinicians (and perhaps some pathologists) alike regarding the value and consistency of diagnoses rendered by the pathology community at large.

With such high agreement, why not digital pathology for second opinions/specimen review for patient referrals/slide review prior to additional surgery/treatment?

And in some cases, with follow up case sharing, even outsmart the consultant?

Ryan Swapp, M.D., Marie Christine Aubry, M.D., Diva Salomao, M.D., and John Cheville, M.D., all of Mayo Clinic’s Division of Anatomic Pathology, recently released a study, “Outside Case Review of Surgical Pathology for Referred Patients: The Impact on Patient Care,” that can now be found as an early online release in CAP Archives of Pathology & Laboratory Medicine.

The Division of Anatomic Pathology reviewed the pathology of nearly all patients that were referredto Mayo Clinic for treatment from 2005-2010. The objective was to identify the rate of major disagreements with diagnoses from external institutions and to characterize the nature and impact of discordant diagnoses on patient care.

Interestingly, they also concede that that their review diagnosis was not always the correct one.

Summary:  Major disagreements occurred only 0.6% of the time (457 of 71,811 cases) from 2005-2010.  The most frequent areas of disagreement were gastrointestinal (80 cases; 17.5%), lymph node (73;16.0%), bone/soft tissue (47; 10.3%), and genitourinary(43; 9.4%).  The disagreeing diagnosis was not always the correct one.  In a subset of these cases for which additional tissue was taken (n=86 disagreements from July 2009 – Dec 2010), this subsequent tissue showed that the original diagnosis was correct 15.1% of the time (13 of 86 cases).

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