Clinical features of medullary thyroid carcinoma (MTC).
1: easily misdiagnosed as small cell hypofractionated carcinoma and undifferentiated carcinoma
2: Produces calcitonin, CEA, 5-HT and other peptide hormones, may have diarrhea, facial flushing and other symptoms
3: 80% are sporadic, the rest are MEN2A, MEN2B and familial MTC
4: Ultrasound features: clear boundary of the mass, some nodules with coarse calcification, high incidence of calcification in lymph node metastases, no cystic changes
5: Tumor does not uptake iodine, 131 iodine scan has no effect
MTC should be considered in the following clinical conditions
A: Carcinoid syndrome with facial flushing and intractable diarrhea
B: MTC in the family
C: higher than normal serum calcitonin
D: Significantly higher than normal CEA in blood without GI tumor
Postoperative follow-up
Calcitonin has high sensitivity and is the most valuable indicator for preoperative diagnosis and postoperative follow-up, reflecting not only clinically obvious primary and secondary metastases, but also postoperative recurrent subclinical lesions, and is also an effective means of preoperative screening for sporadic MTC, but it should be noted that it can be mildly elevated in children, pregnant women, renal failure and some patients with Hashimoto’s thyroiditis.
2. CEA is elevated in more than 50% of patients
3. If local recurrence or lymph node metastasis is suspected, puncture is feasible, and the presence of spindle cells and amyloid material is a diagnostic feature.
4, RET gene mutation is the basis of the pathogenesis of MTC, familial MTC patients have RET mutation, their family members should perform RET gene testing, once there is a mutation should be operated as soon as possible.
A: 95-100% will develop MTC, the age is usually before 30 years old
B: Preventive surgery pathology is at least C-cell hyperplasia (MTC precancerous lesion)
C: Total thyroidectomy for RET gene mutation carriers
At present, RET gene is an early diagnosis method with high accuracy, and it is recommended that MTC patients and their families should undergo RET gene testing.
5. Upper mediastinal metastasis is a characteristic of MTC, postoperative CT review should include the neck and upper mediastinum
6. It is not necessary to strictly restrict the iodine intake of patients.
7, biologically targeted therapy is the hope for MTC (such as vandetanib, etc.)