In this lecture, the following basic steps by which I routinely scan specimens in our hospital will be presented with examples.
1. Evaluate the specimen preparation.
1) Is the incision for the specimen made perpendicular to the skin surface?
2) Is the slice of tissue from volar skin made perpendicular to the furrows of skin?
2. Estimate the specimen size and location.
1) Estimate the size of the lesion from the magnification of the objective lens.
2) Estimate the specimen location.
3. Precaution before evaluation
1) Observe the specimens without clinical information as much as possible.
2) Obtain as much information as possible at low magnification.
4. The steps for observation
1) At low magnification: Check the symmetric properties and circumscription of the lesion based on the following points.
a. Distance from the densest area of the lesion to both ends.
b. Variation of the thickness of epidermis from the center to both ends.
c. Distribution of melanin in the coronoid layer, epidermis, and dermis.
d. Distribution of nests and distance between each nest.
e. Density of solitary distributed melanocytes.
f. Existence of inflammatory infiltration in the dermis and its distribution.
g. Continuity of the spread of nests and tumor cells in both ends.
h. Is the bottom of the lesion smooth or not?
2) At high magnification: Check the details of tumor cells.
a. Tumor cells in the epidermis: Existence of necrosis, atypia (large nucleolus), or mitosis.
b. Other findings in the epidermis: Distribution of melanin in the cornified layer, the existence of tumor cells in the upper epidermis, the polymorphism of tumor cells, the relationship between tumor cells and keratinocytes.
c. In the dermis: An overlapping, crowded, or sheet-like gathering of tumor cells, maturation of tumor cells, mitotic figures, or melanin of tumor cells at the bottom of the lesion.
d. In the adnexal area: The existence of tumor cells in adnexal walls.
5. After provisionally giving a pathological diagnosis, check discrepancies between the pathological diagnosis and clinical findings. Return to the pathological evaluation if necessary.