Various patterns of calcifications may be seen in thyroid cancers on ultrasonography (USG)
of thyroid. Coarse calcifications seen in medullary thyroid carcinoma
(MTC) are generally associated with posterior shadowing on thyroid ultrasound.
We briefly report
this case of MTC with an emphasis on its
radiological features.
A 45-year-old post-menopausal female presented with a goiter
(8 cm ×
7 cm) of ten
years duration. History was uneventful otherwise. Thyroid function tests were:
free T3-2.20 pg/ml (ref. range: 1.71-
3.71), free T4-1.18 ng/100ml (ref.
range: 0.7-1.48) and TSH-1.42 µIU/ml (ref. range: 0.35-4.94) respectively. Subsequently, thyroid
ultrasound revealed prominent
calcifications and increasedvascularity (Figure
1), (Figure 2).
Computed Tomography (CT) scan of neck showed large (80 mm × 78 mm) well defined,
calcified mass lesion in the left lobe of the thyroid (Figure 3). Fine
needle aspiration biopsy (FNAB) confirmed
evidence of MTC. A highly elevated calcitonin (20,000 pg/ml) (ref. range: < 5 pg/ml) was
consistent with the diagnosis of MTC.
MTC may be associated
with dense, irregular foci of calcifications
which are in contrast with homogeneous calcifications of other
thyroid tumors. MTC,
first described by Hazard et al. in 1959, has become the focus of
increasing clinical and experimental investigations.
However, in thyroid
carcinomas, ultrasonographic evidence of
an abundance of calcifications may
be rarely seen nowadays due to improved
health awareness and earlier diagnosis. To conclude, in an asymptomatic patient
with long standing goiter, coarse
macrocalcifications in imaging findings should make the physician vigilant in ruling
out MTC.
