Pathologic Stage III Cutaneous Merkel Cell Carcinoma AJCC v8

**Semantic type:** Neoplastic Process

**Definition:** Stage III includes: IIIA: (T1-4, N1a(sn) or N1a, M0); (T0, N1b, M0); IIIB: (T1-4, N1b-3, M0). T0: No evidence of primary tumor. T1: Maximum clinical tumor diameter equal to or less than 2 cm. T2: Maximum clinical tumor diameter more than 2 cm but equal to or less than 5 cm. T3: Maximum clinical tumor diameter more than 5 cm. T4: Primary tumor invades fascia, muscle, cartilage, or bone. N1a(sn): Clinically occult regional lymph node metastasis identified only by sentinel lymph node biopsy. N1a: Clinically occult regional lymph node metastasis following lymph node dissection. N1b: Clinically and/or radiologically detected regional lymph node metastasis, microscopically confirmed. N2: In-transit metastasis (discontinuous from primary tumor; located between primary tumor and draining regional nodal basin, or distal to the primary tumor) without lymph node metastasis. N3: In-transit metastasis (discontinuous from primary tumor; located between primary tumor and draining regional nodal basin, or distal to the primary tumor) with lymph node metastasis. M0: No distant metastasis detected on clinical and/or radiologic examination. (AJCC 8th ed.)

**Synonyms:** - Pathologic Stage III Neuroendocrine Carcinoma of the Skin AJCC v8