Pathology curriculum

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This curriculum contains the pertinent things a pathologist need to memorize, which can broadly be categorized into:

  • Emergent pathology, mostly relating to intraoperative or frozen section consultations. This includes information that usually cannot be timely looked up on the Internet when needed.
  • Main pitfalls: Most common and dangerous situations where a pathologist may not recognize the need to look something up further or ask a senior colleague.
  • Patterns and signs which can be seen grossly or under the microscope. It confers the ability to translate visuals into words that can be looked up if needed.
  • Knowledge of where to find information for various situations. It includes which person or which search engine is most useful for various clinical situations. Google is generally an appropriate search engine, but sometimes more specific or comprehensive databases are necessary, such as for example ClinVar to look up the pathogenicity of specific genetic variants. The chapter will include a directory of major databases and external guidelines, and how to use them.
  • Proficiency in diagnosing equivocal or borderline cases where readily available sources and evidence usually deal with discrete and specific disease entities and subcategories thereof.  Thus, in the question sections, many questions will be in the format of displaying readily available facts about diseases, including their typical immunohistochemistry patterns, but with equivocal or borderline case presentations.
  • Having an idea of one’s unknowns; being aware of unfamiliar fields. For example, a pathologist generally does not need in depth knowledge about cases that are generally sent out to specialized centers (such as pediatric musculoskeletal oncology), as long as that pathologist is aware of lack of knowledge in that field.
What you need to memorize.jpg
  • Dealing with Internet denialists and their exams. With the ease of access to pathology information on the Internet through smartphones and computers, those studying to for everyday practice as a pathologists should not spend time memorizing what can essentially always be conveniently and timely be looked up in times of need. The topics listed above are already immense enough to cover a lifetime of learning. Nevertheless, the path to pathology certification includes one or more exams, whose questions are largely made up of people who still do not acknowledge the access to the Internet in everyday pathology practice, and therefore this curriculum also includes this chapter.


Other doctors and even laypersons can look up diseases and conditions themselves, including pathology characteristics, without the need for a pathologist consultation, so the expertise of memorizing such readily available information is expendable.

In a world where diseases and conditions can readily be looked up, a major skill that distinguishes a pathologist from any person with Internet access is

Also, unusual or equivocal presentation of very common diseases and conditions are still generally more common than rare diseases, and constitutes a major workload in everyday pathology practice. Most textbooks still give disproportionately large room for rare diseases compared to such presentations. However, strive to master the common conditions (including the most common pitfalls) before diving into the uncommon. Specialists and subspecialists may already have learned the common conditions, at least in their subspecialty, and they will often distract you from this pursuit by presenting rare conditions to you, because that is now interesting to them, but do not spend excessive time or mental effort on such rare conditions.

The goal of this curriculum is to make a pathology trainee able to properly handle at least 95% of cases that are expected at an average general pathology department.



Surprise frozen sections

While most frozen sections can be predicted from schedules of the operating room and thereby be looked up beforehand, this chapter deals with the most common ones that do not offer such preparation time, thus indicating memorization of how to handle them.

(Gather most common situations.)

Other frozen sections

Although these are generally given on schedules of the operating room, any pathologist may end up suddenly covering for another one, and subsequently be presented with the frozen section case without having had the time to look it up beforehand.


Also largely a directory of external guidelines and databases.

Non-emergent pathology questions


Which of the following situations does not have comprehensive guidelines available online?


Ask what are the main locations to look for infection in a specific autopsy case.

Provide algorithm of gram stain etc. and table of main bacteria by various locations.

Where to find information


Provide genetic variant in long format.

- Which database is the best to use to look up the pathogenicity of this variant?

 - ClinVar (correct)

 - gnomAD (population frequencies)

 - PolyPhen (likelihood of protein damaging)

 - PharmGKP (associated treatments)

- In ClinVar, what would you enter

 - A1708V (then BRCA1)

Dealing with Internet denialists and their exams

They take pride in for example memorizing the chromosome locations of even rare mutations, but when being called in for a frozen section of even relatively common specimens such as brain, lung or skin tissues, they may not know how to differentiate even the most common 90% of diagnoses.

An Internet denialist who has memorized something may assume that pathology trainees should memorize it as well, and entire lectures may largely consist of rants of such items. In reality, when something is encountered and looked up something enough times, it will generally get memorized. It is generally more efficient to let time tell which situations will be common versus uncommon, rather than trying to memorize knowledge for even uncommon situations.

Exam studying.


Author: Mikael Häggström [notes 1]

General notes edit

Immediately after sampling, tissue samples should generally be placed in vessels with the correct fixing solution, with a volume that allows them to lie freely in the solution.[1] The standard fixation fluid is generally 10% neutral buffered formalin, which is roughly equivalent to 4% formaldehyde.[2]


  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.

Main page


Selection and trimming

  1. REDIRECT Gross processing

Evaluation of tumors

  1. REDIRECT Evaluation of suspected malignancies


Author: Mikael Häggström [notes 1]

General notes edit

Following are general notes on reporting in pathology.


Selection and trimming

From the stage of selection and trimming, a histopathology report should preferably include:

  • Case:
  • Patient identification and/or sample number
  • Type of tissue sample as described on container
  • Dimensions of original tissue[3]
  • Directions or other features of any inked surfaces.
  • Generally the weight of larger samples[3]
  • Dimensions of pathologic components[3]
  • Whether the entire specimen or representative sections were submitted.

Microscopic evaluation

  • Specimen type and/or surgery type, such as "appendix, appendectomy", for clarification. This is not necessary at all departments.
  • Findings. This is not always necessary, but should be included if the diagnosis is uncertain. One systematic approach is to describe findings from largest to smallest ones. For example, a description of a tumor can start with the demarcation of the tumor, followed by texture, cell shapes, nucleus shapes and chromatin appearance.
  • Diagnosis or most probable diagnoses.
  • In case of malignancy or suspected malignancy:
  • Depth or most distant invasion of malignant findings.[3] Depending on location, it may need to exclude important pathways, such as vascular, neural and/or through capsules or other layers.
  • Whether the resection is radical or not.


Factors supporting a relatively more comprehensive report, particularly in the inclusion of negated findings:

  • Lack of explanation from existing evidence. For example, an inflamed appendix that fits the medical history does not need detailed mention of harmless incidental findings.
  • Double-reading: If your report is likely to undergo double reading by another pathologist before sign-out, it needs to be more detailed, because the doctor who will do the double-reading then knows that you have looked at those locations.
  • Highly suspected locations, such as given from the referral.
  • Defensive precautions, which appears to be more common among doctors in the Unites States compared to for example Europe.[4][5]

Multiple instances of the same type of pathology (such as lung nodules) can often simply be reported as such, at least with a particular mention of the largest or the most severe example thereof.

Where findings are made, general statements of clearing a region should still be given, such as: "There is a 18.0 cm curvilinear well-healed thin scar in the left thorax. Otherwise, there are no puncture marks or healed surgical scars on the torso." The main exception is for aspects that are barely worth mentioning, in which case the description of the finding may imply that the aspect has been considered in general.


The same word used describing the certainty of findings can refer various probabilities, differing between pathologists as well as clinical situations. The following is a suggestion of words, in an attempt to sort them from most to least probable:

(non-lethal condition) cannot be excluded
not likely
(lethal condition) cannot be excluded

For findings and diagnoses, is preferable to write "negative for..." rather than "no..." to emphasize the possibility of false negative findings.


Whenever possible, give numerical quantities of sizes, rather than descriptions that are subjective (such as "small" or "large") or variable (such as "apple-sized").


The information contained in the reporting sections in Patholines assume that the clinician has requested the exam for the topic of the article at hand, but should be tailored to any particular questions or requests by the clinician. Any relevant findings beyond the issues or questions raised by the clinician should also be mentioned.

The most important findings can be moved to near the top of the report if feasible, but doctors performing subsequent double-reading may prefer a consistent anatomic order.

If a certain grammatical rule has a risk of making the report less clear to the reader, ignore it.

Restrict acronyms/abbreviations to those who are certainly well known among all doctors, such as "cm".[notes 2]

Generally describe what can be seen rather than processes (such as preferring "an abundance of" rather than "proliferation of").

Skin excisions

In skin cancers, "peripheral" or "radial" margins are preferred rather than "lateral".[6][notes 3]

See also


  1. For a full list of contributors, see article history. Creators of images are attributed at the image description pages, seen by clicking on the images. See Patholines:Authorship for details.
  2. Acronyms/abbreviations increase reading speed only if the reader is familiar with the abbreviated terms:
  3. A "lateral" margin may be interpreted as opposite to the "medial margin"

Main page




  1. Katarzyna Lundmark, Krynitz, Ismini Vassilaki, Lena Mölne, Annika Ternesten Bratel. Handläggning av hudprover – provtagningsanvisningar, utskärningsprinciper och snittning (Handling of skin samples - Instructions for sampling, cutting and incision. KVAST (Swedish Society of Pathology). Retrieved on 2019-09-09.
  2. . Paraformaldehyde, Formadehyde and Formalin. Duke University. Retrieved on 2019-12-17.
  3. 3.0 3.1 3.2 3.3 . An Example of a Melanoma Pathology Report. Melanoma Foundation. Retrieved on 2019-09-24.
  4. Studdert D. M.; Mello M. M.; Sage W. M.; DesRoches C. M.; Peugh J.; Zapert K.; Brennan T. A. (2005). "Defensive medicine among high-risk specialist physicians in a volatile malpractice environment ". JAMA 293 (21): 2609–2617. doi:10.1001/jama.293.21.2609. PMID 15928282. 
  5. Steurer J.; Held U.; Schmidt M.; Gigerenzer G.; Tag B.; Bachmann L. M. (2009). "Legal concerns trigger PSA testing ". Journal of Evaluation in Clinical Practice 15 (2): 390–392. doi:10.1111/j.1365-2753.2008.01024.x. PMID 19335502. 
  6. David Slater, Paul Barrett. Standards and datasets for reporting cancers - Dataset for histopathological reporting of primary cutaneous basal cell carcinoma. The Royal College of Pathologists. February 2019