Melanoma: Pathology report recommendations

Recommended clinical information to be provided to pathologist

Essential Strongly Recommended Optional
Age of patient  Biopsy technique (excisional/incisional)  Clinical description/Level of suspicion 
Gender  Size of lesion  Dermatoscopic features 
Anatomic location    Photograph 
    Macroscopic satellitosis 

Strength of Recommendation: A Level of Evidence: I

Recommended histologic features of primary melanoma to be Included in the pathology report

Essential Optional 
Tumor (Breslow) thickness; mm  Angiolymphatic invasion 
Ulceration Histologic subtype 
Dermal mitotic rate; mitoses per square mm Neurotropism 
Peripheral and deep margin status (positive/negative)  Regression 
Anatomic level of invasion (Clark level)* T-stage classification 
Microsatellitosis Tumor infiltrating lymphocytes 
  Vertical growth phase

*Essential for staging only in tumors ≤1 mm in thickness when mitotic rate cannot be assessed; optional for tumors > 1 mm in thickness.
Strength of Recommendation: A&B Level of Evidence: I&II

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Definitions of histologic features
Term Definition
Clark Levels
Level I Tumor confined to epidermis
Level II Tumor present in papillary dermis
Level III Tumor fills papillary dermis
Level IV Tumor present in reticular dermis
Level V Tumor present in subcutis
Vertical growth phase Presence of 1 or more clusters of dermal tumor cells larger than the largest epidermal tumor clusterand/or presence of any dermal mitotic activity
Tumor regression Apparent loss of dermal tumor with associated nonlamellar fibrosis, mononuclear cell inflammation, and vascular proliferation or ectasia
Microsatellitosis Nest(s) of tumor cells (>0.05 mm in diameter) located in reticular dermis, subcutis, or vessels, separated from invasive component of tumor by≥0.3 mmof normal tissue


When a biopsy is performed of a lesion clinically suspicious for primary cutaneous melanoma, the expert work group recommends that the following pertinent information is provided to the pathologist. For identification purposes, the age and gender of the patient and the anatomic location of the lesion must be included.20-34 The clinical information in the pathology report should contain the type of surgical procedure performed (ie, biopsy intent–excisional or incisional) and size of the lesion. Additional optional, but desirable, clinical information include ABCDE criteria, dermatoscopic features, a clinical photograph, and the presence or absence of macroscopic satellitosis.

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