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Start free with EleplanIsolated familial medullary thyroid carcinoma
ORPHA:99361Disease
Also called Hereditary isolated MTC · Isolated familial MTC
What it is
A rare thyroid tumor characterized by a malignant neoplasm derived from the calcitonin-secreting parafollicular C-cells of the thyroid and occurring familially, but not as a component of multiple endocrine neoplasia syndromes. The commonly multifocal, bilateral nodules are typically located at the junction of the upper and middle thirds of the thyroid lobes. Clinically, patients may present with diarrhea, flushing, or weight loss caused by excessive secretion of calcitonin by the tumor. In rare cases, the tumor can also cause Cushing syndrome due to ectopic corticotropin production.
Key facts
- Inheritance
- Autosomal dominant
- Classified as
- Disease
Recorded for the broader condition
- Prevalence
- 1-5 / 10 000Rare thyroid carcinoma
- Age of onset
- AdultRare thyroid carcinoma
Orphanet records these for the broader condition rather than for this specific form. They are a starting point, not a figure for this subtype — subtypes often differ, and some are defined by being rarer than the condition they sit under.
Genes
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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