Mycosis Fungoides Cooperative Group TNMB classification of cutaneous T cell lymphoma (CTCL)

* For skin, patch indicates any size lesion without significant elevation or induration. Presence/absence of hypo- or hyperpigmentation, scale, crusting, and/or poikiloderma should be noted.
¶ For skin, plaque indicates any size skin lesion that is elevated or indurated. Presence or absence of scale, crusting, and/or poikiloderma should be noted. Histologic features such as folliculotropism or large-cell transformation (>25 percent large cells), CD30+ or CD30-, and clinical features such as ulceration are important to document.
Δ For skin, tumor indicates at least one 1 cm diameter solid or nodular lesion with evidence of depth and/or vertical growth. Note total number of lesions, total volume of lesions, largest size lesion, and region of body involved. Also note if histologic evidence of large-cell transformation has occurred. Phenotyping for CD30 is encouraged.
◊ For node, abnormal lymph node(s) indicates any lymph node that on physical examination is firm, irregular, clustered, fixed, or 1.5 cm or larger in diameter or on imaging is >1.5 cm in the long axis or >1 cm in the short axis. Node groups examined on physical examination include cervical, supraclavicular, epitrochlear, axillary, and inguinal.
§ A T cell clone is defined by polymerase chain reaction or Southern blot analysis of the T cell receptor gene.
¥ For viscera, spleen and liver may be diagnosed by imaging criteria alone.
‡ The clone in the blood should match that of the skin. The relevance of an isolated clone in the blood or a clone in the blood that does not match the clone in the skin remains to be determined.