e-Manual for Specimen Gross Examination in Surgical Pathology (4rd Ed)
Key Elements to Observe (MICROPALMS)
M atch specimen label with requisition form
I dentify specimen by its label
C linical information
R equest of the clinician
O rientation of the specimen
P arts or portion of the specimen
A ppearance of the specimen and lesion
L esion, location and extent
M argins of the specimen
S ampling and sections
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This is the first step in error prevention. Identification of the specimen label must be documented (in the pathology report) for each specimen. It is important to match identification information on the specimen container with that on the requisition form while dictating "Received in formalin' labeled 'John Doe', and 'appendix' ..." in the report. See also General Advice on Gross Examination
A match between the container label and requisition form does not necessarily guarantee that the specimen has been labeled correctly. For example, a container labeled as "Stomach biopsy" may contain a long needle core biopsy of the liver, or a gallbladder may be in a container labeled as "appendix". Such errors mainly occur in the surgical procedure room or nurses' station where a wrong label is attached to the container or the specimen is put into the wrong container. Although the specific tissue type may not always be apparent on gross inspection (e.g., stomach biopsy vs. colon biopsy), it should be possible to detect major discrepancies macroscopically in most instances. It is important to determine whether a specimen is correctly designated whenever possible especially prior to its dissection and tissue processing (see also Elements of the Gross Description).
In addition to the patient's demography, information provided by clinician is of great help in generating likely differential diagnoses as the focus of gross examination. For example, the main differential diagnosis for a liver explant from a 56-year old man with end-stage liver disease usually includes alcohol, hepatitis C, hemochromatosis, alpha-1-antitrypsin deficiency, and hepatocellular carcinoma, whereas a liver explant from a 25-year old female with fulminant liver failure is unlikely to be due to alcohol, hemochromatosis or hepatocellular carcinoma. Gross examination should be guided by the differential diagnosis and should always accomplish two tasks: 1) look for expected features, and 2) detect "unusual" features that may lead to an unexpected diagnosis.
Ignoring or overlooking clinicians' specific requests often results in very unpleasant and "unforgivable" medical errors that are easily avoidable. For example, requested bacterial culture of a lung nodule can no longer be performed if the specimen is transferred to formalin or/and contaminated in the pathology lab. If there is doubt or reasons (e.g., specimen submitted in formalin by the clinician) that prohibit such requested test, a verbal clarification and/or written documentation should be made to avoid later problems.
Lesions, important anatomic structures, and resection margins are not always easily identifiable or properly designated, yet these are important to recognize for correct diagnosis and assessment. It is therefore imperative to determine whether or not a resection specimen is oriented before touching the specimen, and to document as such. To assist in specimen orientation, clinicians often use ink, sutures, or staples to mark areas of interest. Do not remove these orientation markers before specimen orientation is secured (e.g., by painting the specimen with ink yourself). Also avoid pulling sutures or staples when handling the specimen, since this may result in detachment of the orientation markers, resulting in loss of specimen orientation. Not infrequently, a clinician has to be called in to clarify specimen orientation. Once orientation is appreciated, specific measures (e.g., paint with multiple colors) must be taken to allow gross-microscopic correlation.
Anatomically-related structures are not always submitted as an integrated specimen. For example, gallstones are often received outside the gallbladder lumen but within the same container if the gallbladder has been surgically opened in the operating room. Different parts of the submitted specimen must be identified whether they come connected or not. The presence or absence of an anatomically related portion of a specimen should also be documented. Examples include an ileocolectomy specimen from a patient who has had a prior appendectomy, a uterus without ectocervix or with an amputated cervix received separately, and a uterus with detached fallopian tubes and ovaries. See also Elements of the Gross Description.
A good description of a lesion should enable the reader to re-create a graphic mental image closely reflecting the features of the lesion. The description is important for generation of a differential diagnosis and correlation with microscopic findings. An orderly description of essential aspects of the physical appearance is preferred. Some key aspects are: size, border (circumscription, demarcation, etc.), shape (roundness vs. irregularity, lobulation, etc.), architecture (solidity, nodularity, cavitation or cystic features, etc.), color, pattern (uniformity, trabeculation, etc.), consistency (firmness, softness, rubbery or fleshy texture, etc.), secondary changes (hemorrhage, necrosis, calcification), and content (mucoid, serous, pus). See also Elements of the Gross Description.
All surgical (tissue) specimens should be assumed to harbor structural abnormalities (lesions) until proven otherwise. In addition to obvious lesions, care must be taken to identify subtle or unexpected changes. If no obvious abnormality is noted, consult with another pathologist or the clinician, take additional measures (e.g., gross photography) to document the absence of a lesion, and submit more tissue sections. Equally important is documentation of the location and extent of involvement by the identified lesion since stage and adequate management (esp., if it is malignant) depend on these factors (i.e., size, margins, lymphovascular invasion, lymph node status, etc.). Different parameters may be used to measure the extent of involvement (predominantly by tumor) depending on the organ and type of tumor. For example, the size of a malignant tumor is a key parameter of tumor extent in a solid organ, whereas the depth of invasion becomes a more critical measure of extent of involvement in a hollow organ.
The guiding principle of surgical treatment is "to live without it" ("it"= lesion), which is determined by two key parameters: negative resection margins and absence of lymphovascular invasion/metastasis. Resection margin is a critical element in gross examination (while lymphovascular invasion is assessed microscopically). A resection margin is defined as a surgically created plane of separation from the rest of the body in a resected specimen. For example, the right middle lobe of the lung obtained by lobectomy typically has one resection margin, i.e., the hilar bronchovascular margin; however, if the visceral pleura of the lobeis adhesed to the chest wall or to an adjacent lobe, the area of adhesion in the specimen also becomes a margin since it is a plane of surgical separation necessary for the resection. A segment of transverse colon is generally considered to have a proximal and a distal resection margin, whereas the rectum also has radial margin since the resection requires separating the rectum from the surrounding pelvic soft tissue.
Adequate sampling of a specimen requires diagnostic knowledge and an understanding of how the choice of tissue sections will impact the final report. For example, it is important that samples be taken from the capsular area rather than from the center of a thyroid follicular neoplasm since distinction between follicular adenoma and carcinoma relies on identification of capsular invasion. Specifics of a particular case may justify deviation from the typical grossing protocol. Depending on the case scenario, a similar lesion may be sampled in different fashions. In a hollow organ (e.g., esophagus, colon), if a tumor is located <1.0 cm from the resection margin (end) of a segmental resection specimen, longitudinal sections that include the tumor and (inked) margin should be taken, whereas a cross section of the margin is preferred if the tumor is several centimeters away from the margin. The extent of a lesion (especially a malignant tumor) is as important as the diagnosis clinically, since stage and adequate management also depend on the extent of involvement (i.e., size, margins, lymphovascular invasion, and lymph node status, in particular). Thus, tissue sampling must also aim to accurately assess extent of involvement. See also Elements of the Gross Description.
There is nothing more dangerous than a man with a sharp knife but with no idea what he's doing.