The term "grossing" means inspecting the specimens, describing and measuring the tissue, inking if needed, and sectioning the tissue to be processed for diagnosis. The skin sample provides the most diagnostically valuable parts of a specimen for the pathologist's review. The gross description provides information that aides the dermatologist or dermatopathologist in rendering a diagnosis during microscopic evaluation of the tissue.
Although the topic of skin gross examination is too broad (and varied) to be covered in its entirety in this course, the content is reflective of the most common grossing practices in the dermatopathology laboratory. Gross examinations can be performed by: pathologists, dermatologists, pathologist assistants, lab personnel qualified to perform high complexity testing per CLIA '88.
General Considerations During Gross Examination
- First and foremost, the patient information on the requisition and on the specimen container MUST match in its entirety. This includes at least three patient identifiers as well as the specimen site(s). Requisitions typically identify the surgical procedure, such as punch, shave, excision, and so on. Any missing, conflicting, or unclear information must be investigated before proceeding. Also, the cassette number/ bar code must match the specimen as well as the requisition. Most errors occur during this pre-analytic phase.
- The grossing station must be well ventilated to prevent inhalation of formaldehyde fumes. Personal protective equipment (PPE) should include disposable gloves and lab coat, as well as protective eye wear. Blades and sharps used during grossing must be disposed of in approved biohazardous waste containers.
- One specimen container should be opened at one time during grossing to prevent mix-ups.
- The number of pieces in each container should be noted. In the case of curettage, samples are measured in aggregate, since there may be over a dozen fragments submitted.
- The color description of skin tissue will be most often "tan." Unusual skin surface or pigmentation should be noted.
- Measurements of the skin surface dimensions and depth should be documented. Any tissue that is small enough to slip through the cassette holes should be submitted whole and wrapped in processing tissue paper or a processing mesh bag.
- Tissue should be inked only if it conveys information such as orientation and margins in excisions, or which side to embed down. Inking cut surfaces of tissue one color will help the embedding tech determine which surface should be embedded down, where inked surfaces will meet the blade first during the microtomy process. Inking is typically reserved for excisions. Inking margins on biopsies is not required since a second procedure is anticipated based on the diagnosis of the biopsy.
- Tissue should be sectioned according to accepted protocols for the laboratory. Generally, the sections should be approximately 3 -4 mm thick/wide. Skin grossing protocols must be standardized for all grossing personnel so that the results are consistent and quality is reproducible.
- Tissue should be submitted for the appropriate paraffin processing protocol, such as biopsy or routine processing.
Although most grossing techs are not familiar with the embedding and microtomy of tissue, familiarity with those techniques is a necessary prerequisite to ensure the quality of grossing in dermatopathology. Isn't the focus of grossing, after all, the proper embedding of a skin sample?