An Example of a Melanoma Pathology Report

This is an example of a pathology report for a melanoma diagnosis. The purpose of the report is to describe the specific characteristics of the melanoma that support the diagnosis, and to give information about prognosis. It will help your doctor determine the best melanoma treatment options for you.

Date of Biopsy: The date the biopsy was submitted

Submitting Service/Physician: Your doctor

Accession #: A number assigned to the biopsy specimen

Patient: Your name

Sex: Your gender

DOB: Your birthday

MRN: A medical record number

Clinical History: A description by your physician of the lesion that was biopsied. Usually a doctor will include size, location, and what he is concerned about. (Example: a 7-mm eroded pigmented papule from the left upper back. Please rule out an atypical melanocytic nevus vs. melanoma.)

Gross: A description of the actual size of the biopsied tissue and what it looked like to the naked eye. This is used by the pathologist for identification of the tissue. (Example: One container of formalin, labeled with the patient’s name, and MRN, which contains a bisected skin shave, 5mm depth x 12mm diameter. The epidermis is wrinkled, pink-tan, with areas showing purple preoperative ink)

Diagnosis: A summary of the findings and a diagnosis. (Example: MALIGNANT MELANOMA, 2.4mm in thickness, ulceration not seen)

Description: A description of the appearance of the biopsy under the microscope. There are specific features that are typically commented upon. (Example: A shave of skin demonstrates epidermal ulceration overlying a collection of irregular melanocytes. There is pagetoid spread of melanocytes into the epidermis. Multiple bizarre nuclei are appreciated. There are nests of atypical melanocytes extending down into the dermis without normal maturation.)

Additional Features: In the case of melanoma, pathologists will specifically comment on features that are relevant for prognosis and treatment. These are sometimes included in the description but also may be in list form as shown below:

Diagnosis: Malignant Melanoma

Tumor Site: Location on the body from which the biopsy was taken

Histologic Type: Superficial spreading, nodular, lentigo maligna, acral lentiginous, desmoplastic or unclassified

Level of Invasion (Clark Level): Clark Level was replaced in the revised melanoma staging system in 2010 by more reliably predictive features (mitotic count and ulceration). It is now only used to stage thin melanomas (< 1mm).

Growth Phase: Radial growth phase (present or absent) Vertical growth phase (present or absent). This describes whether the melanoma has begun an invasive pattern.

Greatest Thickness (Breslow Depth): It describes in millimeters the thickest part of the melanoma. It is very important for prognosis. A thinner tumor has a better prognosis.

Mitotic Count (Mitotic Rate): Mitosis is the process by which one mature cell divides into two identical cells. The pathologist counts the number of actively dividing cells (mitoses) that they see. This is seen in many cancers, including melanoma. Averaging this number gives the mitotic count, which is stated as the number of mitoses per square millimeter (mm). Most often this count is reported as:

  • Less than or equal to 1 per square millimeter
  • Or the actual number is provided

A higher mitotic count means more tumor cells are dividing at a given time and is associated with a worse prognosis.

Tumor Infiltrating Lymphocytes (TILs): Lymphocytes are immune cells. Lymphocytes can be present in a melanoma and are described as “brisk,” “nonbrisk,” “sparse”, and “absent.” A brisk immune response has been associated with a better prognosis. However, the true significance of this criterion is still controversial, and some pathologists do not report it.

Regression: Refers to an area of the tumor without active melanoma cell growth and is thought to be evidence that some of the melanoma was destroyed by one’s immune system. There are conflicting reports on whether this finding has useful prognostic significance. Historically, regression has been associated with a worse prognosis.

Ulceration: The breakdown or loss of the top layer of the skin (the epidermis). The presence or absence of ulceration is determined by the pathologist when he reviews the specimen under the microscope. Having ulceration is associated with a worse prognosis. Patients who report bleeding from their melanoma often have ulceration in the biopsy.

Satellite Lesions: Also called “local metastasis.” They are small nodules of melanoma located more than 0.05mm from the primary lesion but less than 2cm. They are described as being present or absent. Some satellite lesions (macroscopic) can be seen with the naked eye. Others, which are smaller (microscopic) can be found only by the pathologists. Both macroscopic and microscopic lesions are reported in the pathology report.

Blood Vessel / Lymphatic Invasion: Evidence that melanoma cells have entered the blood vessels or lymphatic system. The presence of this finding is associated with a worse prognosis.

Neural Invasion: Evidence that melanoma cells are entering the local nerve fibers. The presence of this finding is associated with a worse prognosis.

Margins: Margins are the edge of a biopsy or surgical excision specimen. If melanoma extends to the edge of the sample (the margins), then it is presumed that the biopsy or excision did not remove the entire tumor. Deep margins are located at the base of the biopsy/specimen and lateral margins are the side edges of the biopsy/specimen. If there is no tumor extending to the margins, the pathologist will describe how close the lesion came to the edge. (Example: tumor extends to within 2 mm of the margin). The thickness of the melanoma primary is used to guide the recommended margin of normal tissue the surgeon plans to remove at the time of surgery.

Recommendations: Based on all the above information, the pathologist may make initial recommendations to the doctor, including whether another biopsy needs to be done to get additional tissue, or whether the doctor should perform an excision of the lesion to ensure complete removal.

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