Cutaneous Metastasis of Medullary Carcinoma Thyroid Masquerading as Subcutaneous Nodules Anterior Chest and Mandibular Region

Table 2

Molecular classification of MCT (Modified from 2012 Europen thyroid cancer association guidelines and with work done by Boichard et al. [8]).

Hereditary MTC (25% Cases): Associated with almost all cases with germline RET mutation (Exon 5, 8, 10, 11, 13, 14, 15 & 16).
- MEN 2A: 85% cases mutation at Exon 11, codon 634
Other mutations Exon 10 and 11, codon 609, 611, 618, 620
- MEN 2B: Exon 16, codon 918 (Most common)
- Disseminated and aggressive variant (commonly in children and young): M918T
Sporadic MTC (75% of all cases):
- RET positive group: 35% cases with somatic RET mutations
- RET negative group:
(1) Criteria: Negative for common germline mutations in Exon 5, 8, 10, 11, 13, 14, 15 & 16
(2) Other Mutations to be identified:
(i) RAS mutation—(Almost 80% of remaining RET negative cases)
(ii) H-RAS (>50%): Exon 2, codon 13; Exon 3, codon 61; Exon 4, codon 63
(iii) K-RAS (<30%): Exon 3, codon 61; Exon 2, codon 13; Exon 4, codon 117