Clark level
Oncology, staging and radiology
Also known as: Clark's level of invasion · Clark-Level · Invasionslevel nach Clark · Clark seviyesi · Clark level of invasion (cutaneous melanoma, historical)
What it is for
The Clark level describes which anatomical skin layer an invasive cutaneous melanoma reaches. It is less reproducible than Breslow thickness, which replaced it for staging.
Classification
| Category | Description |
|---|---|
| Level I | confined to the epidermis (melanoma in situ). |
| Level II | invasion into the papillary dermis. |
| Level III | invasion filling the papillary dermis up to the interface with the reticular dermis. |
| Level IV | invasion into the reticular dermis. |
| Level V | invasion into the subcutaneous fat. |
| Status | the AJCC 6th edition (2001) still used the Clark level to subdivide thin (T1) melanomas; the 7th edition mainly used the mitotic rate instead, and the 8th edition uses only thickness and ulceration for T. |
Source
The histogenesis and biologic behavior of primary human malignant melanomas of the skin
Cancer Res 1969;29:705–727 (Clark WH Jr et al.)
PMID: 5773814
- Edition
- Clark 1969; no longer part of the AJCC 8th edition T category (historical, still seen in older reports)
- Checked on
Summary of the published classification in our own words. Not a substitute for the original publication.
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