Art by Davidoff

Ashley Davidoff MD

Introduction

The Butterfly Shaped Organ

The butterfly shaped form of the thyroid gland is appreciated in this image.

Butterfly in Sepia

The butterfly shaped form of the thyroid gland is appreciated from a more subtle perspective in this sepia rendering

The Normal Thyroid

The H shaped form of the thyroid gland is appreciated in this image. The isthmus may be broad in its craniocaudad dimension or may be relativel narrow. In the anetroposterior dimension it is only about 3-5mm thick

Thyroid Moods

Thyroid Moods

A Thyroid for All Seasons

A thyroid for all seasons Spring – pink summer green fall orange winter gray

Artistic Rendition Showing the Combined Macroscopic and Microscopic Features

The normal gland has a unique appearance both macroscopically and microscopically. Its name implies a shield like shape, and it mirrors the shape of the thyroid cartilage. It is brownish red in color and at a histological level is made of variably sized rounded glandular rosettes with spaces that contain colloid in which thyroglobulin is stored. Thyroglobulin is a precursor of the thyroid hormones.. Storage of endocrine products outside of the cell is a unique feature of the thyroid gland.

The Thyroid Gland – Unique Appearance

Artistic rendition of the normal thyroid gland The histological make up of the thyroid has a unique appearance consisting of variably sized rounded glandular rosettes with spaces that contain a homageneously pink materail called colloid, subtended by a basal layer of cells that secrete the colloid. This diagram shows these rosettes which in fact make up the whole gland. The base of the rosettes contain a single layer of an epithrlium almost cuboidal cells that secrete the colloid (shown in navy blue)

Massive Non Toxic Multinodular Goiter

This 75 year old male presents with an asymptomatic multinodular goiter, consisting many nodules of varying size and density, some with macrocalcifications as seen by coronal CT reconstruction (a,b) and axial images (c,d). The windows of the CTscan have been narrowed (a,c), to enhance the morphological characteristics of the components of retrosternal goiter. Each lobe of the thyroid measures about 12 cms in sagittal 6cms. in transverse and 12cms in A-P dimension. These findings are consistent with a non toxic multinodular goiter.

Thyrotoxicosis

This diagram shows the structural possibilities in a patient who presents with thyrotoxicosis. Reading from upper left the normal thyroid is shown for reference of size and normal activity (pink). Next is the single toxic nodule that suppresses the function of the gland and the also causes the rest of the gland to shrink. This is followed by a diagram of multiple toxic nodules and the gland in this case may also be smaller than normal. The lower series of images include Grave’s disease, which is the most common cause of thyrotoxicosis, followed by acute thyroiditis and then subacute thyroiditis.

Exopthalmos and Grave’s Disease

Bilateral exopthalmos or bulging of the eyes is most commonly associated with Grave’s disease which is an autoimmune disease associated with thyrotoxicosis. Upperlid retraction results in the ability to see the whites of the eyes on both sides of the iris.

Changes in Disease

A variety of appearances of the thyroid gland in disease including (from top left to right a simple cyst (yellow) the small atrophied gland seen in hypothyroidism, the large hyperemic gland seen in acute thyroiditis and Graves disease, the hemorrhagic cyst (maroon) normal, multinodular goiter of cysts (yellow), heterogeneous (light green) and solid (dark green), the malignant nodule, hot nodule with secondary atrophy of the gland, and the large multinodular retrosternal gland.

The Normal Sized Thyroid Gland

The normal sized thyroid gland

Thyrotoxicosis

The diffusely hyperactive gland is enlarged and hypermetabolic

The Diffusely Enlarged Gland

Enlarged thyroid gland The histological make up of the thyroid shows an overall increase in the volume of the thyroid with the individual glands still being normal – just more of them resulting ina rotund appearance This appearance would be in keeping with an acute thyroiditis where the gland has become swollen.

Acute Thyroiditis

Multinodular Goiter

Enlarged thyroid gland Several large nodules of varying size are scattered throughout the gland. This basic appearance is characteristic of a multinodular goiter.

Small Thyroid Gland

Small thyroid gland The thyroid gland is depicted as a small shrunken gland characteristsic of entities such as end stage thyroiditis and myxedema.

Foundation Principles

This diagram frames the underlying principles and approach to the thyroidin this module

Image Courtesy Ashley Davidoff MD 93852g05c.8s