Familial medullary thyroid carcinoma associated with cutaneous lichen amyloidosis.
BACKGROUND
This is a report of a patient with a novel genotype-phenotype relationship of a c804 mutation of the RET proto-oncogene manifesting as medullary thyroid carcinoma (MTC) and cutaneous lichen amyloidosis (CLA).


CONCLUSIONS
Clinical data were obtained for patient appearance and laboratory results. Analyzed were histopathology of the skin lesion and thyroid gland, genetic mutation, and family pedigree. Skin histology and histochemistry were consistent with CLA. Serum calcitonin levels were moderately elevated. Thyroid histology demonstrated a 4 mm focus of MTC. Measurements of serum parathormone, calcium, and plasma metanephrines were normal. DNA analysis demonstrated a mutation in codon 804 of the RET proto-oncogene resulting in a Valine to Methionine (V804M) substitution. Genetic testing in two siblings revealed the same mutation.


CONCLUSIONS
This is the first description of a patient with CLA not associated with a mutation in codon 634. The patient is one of the few with a V804M mutation in whom the clinical expression did not fully conform to the definition of familial MTC.
Rothberg
Amy E
AE
Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109-5354, USA. arothber@med.umich.edu
Raymond
Victoria M
VM
Gruber
Stephen B
SB
Sisson
James
J
D000686:Amyloidosis / Q000150:complications* / Q000235:genetics*; D002116:Calcitonin / Q000097:blood; D018276:Carcinoma, Medullary / Q000150:complications* / Q000235:genetics*; D004247:DNA / Q000235:genetics; D005260:Female; D006801:Humans; D008875:Middle Aged; D009154:Mutation / Q000502:physiology; D010375:Pedigree; D000090063:Proto-Oncogene Mas; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012867:Skin / Q000473:pathology; D012871:Skin Diseases / Q000150:complications* / Q000235:genetics*; D013964:Thyroid Neoplasms / Q000150:complications* / Q000235:genetics*; D013965:Thyroidectomy
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D002116:Calcitonin; D004247:DNA; D051096:Proto-Oncogene Proteins c-ret