Virtual Pathology Slide Atlas


Thyroid: Adenoma 


Case 1 R hemithyroidectomy for 40mm solitary nodule.  This haematoxylin and eosin stained slide suggested a follicular variant of papillary carcinoma on the basis of the circulated slide, however the submitting pathologists were able to show that the lesion was Ck19 –ve, and after discussion this lesions was reclassified as a Follicular Adenoma. This highlights some of the difficult problems in distinguishing follicular adenoma from follicular variant of papillary carcinoma, and the relative lack of interobserver reproducibility in these lesions when the lesion is entirely encapsulated, and without capsular or vascular invasion.


Case 2 Female in 50's, previous radioiodine Rx for thyrotoxicosis. Nodular gland, FNA suggestive of oncocytic follicular neoplasm with a macroscopic nodule in the left lobe of the thyroid 15mm in size which stained with galectin 3 and Ck19.  The slide shows two well circumscribed nodules comprising oncocytic cells which were encapsulated, and without evidence of capsular invasion. The papillary areas appear to be hyperplastic rather than forming neofibrovascular cores. A consensus diagnosis of ‘Papillary Oncocytic Neoplasm’ was made as it is uncertain whether this lesion is benign or malignant. The thyroid also shows features of radioiodine therapy and possible Hashimoto's thyroiditis. The Ck19 and galectin 3 result could have been false +ve if a biotin immunohistochemical detection system was used because oncocytic tumours typically are rich in endogenous biotin


Case 3 Male, late 50’s, right thyroid mass with a prior FNA diagnosis suspicious of medullary carcinoma, serum calcitonin normal, total thyroidectomy with right lobe containing a 37mm diameter solid yellow tumour. The diagnosis was an adenomatoid nodule of Hurthle cell type, see here   and here  with marked FNA-related changes  including infarction and haemorrhage but no evidence of malignancy. The nuclear features in this case are not sufficiently convincing for papillary carcinoma carcinoma and definite capsular invasion as opposed to entrapment is not seen. 


Case 4. Male, late 40’s, total thyroidectomy, lesion in left lobe of thyroid. A  Hurthle Cell (Oncocytic) Adenoma  of the thyroid showing typical nuclear features.