Slide 93.Medullary carcinoma, Thyroid

A. Brief Descriptions

  1. Derived from the parafolliular cells, C cell, secrete calcitonin.

  2. Sporadically (80%), MEN syndrome IIA or IIB.

  3. One lobe (sporadic), bilaterality and muticentricity(familial).

B. Gross Findings

  1. Well circumscribed, gray-white lesion.

  2. Range in size, they may be barely visible or may replace the entire thyroid, the larger lesions are sharply circumscribed but not encapsulated.

C. Micro Findings

  1. Nests of cells separated by stroma with prominent small capillary vasculature.

  2. Round or oval or angulated or spindle cells with uniform, round to oval nuclei& ill-defined eosinophilic or amphophilic and finely cytoplasm.

  3. Amyloid deposition which show green birefringence in polarized light after Congo red stain. (extensive amyloid deposition in our slide).

D. Others:


E. Reference

  1. Robbins Pathologic Basis of Disease, 6th ed.  P.1146.





Fig. 93-1(Congo stain)




Fig. 93-2 (Congo red stain under polarized light)




Fig. 93-3 (4X)




Fig. 93-4 (4X)




Fig. 93-5 (10X)




Fig. 93-6 (10X)




Fig. 93-7 (20X)




Fig. 93-8 (20X)






Fig. 93-9 (20X)




Fig. 93-10 (40X)




Fig. 93-11 (40X)