Endocrine glands:
Lab Pathology of pituitary and ThyroidNormal anterior pituitary gland (pars distalis) - High power Note the mixture of cell types, including the red-staining acidophils, purple-staining basophils, and the chromophobes, whose cytoplasm stains only weakly. The
Normal anterior pituitary gland, immunohistochemical stain for growth hormone (hGH) - Medium power somatotrophic (hGH-secreting) cells have been labeled with an antibody to hGH. The antibody, in turn, has been linked to a chromogen that stains the somatotrophic cells brown.
Morphology of Pituitary Adenomas
Variable pattern of growth May be small, hormonally inactive, incidental findings May be small but cause hormone excess and these are called as MICROADENOMAS less than 10 mm. May be rapidly growing mass lesions as MACROADENOMAS more than 10 mm. Generally are poorly encapsulated.The Spectrum: Pituitary Tumors
Microadenoma: Incidental finding or the cause of serious diseaseMacroadenoma
This MRI demonstrates a large lesion involving the sellar and suprasellar regions. The patient has been injected with contrast material, which causes this particular mass to enhance as a bright (white) lesion
Microscopically:
are formed of fairly uniform sheets of cells. The cells are growing in a diffuse pattern and lack the characteristic nesting architecture of the normal anterior pituitary gland If hemorrhage it is called as pituitary apoplexy.Note the monomorphic cellular proliferation. The cells are growing in a diffuse pattern and lack the characteristic nesting architecture of the normal anterior pituitary gland
At higher magnification, the comparatively uniform, amphophilic staining pattern of the neoplastic cells is apparent . (amphophilic means that the color is between eosinophilic and basophilic)
This specimen shows a pituitary adenoma discovered incidentally in a patient who died of unrelated causes. Pay special attention to the relationship between the adenoma and adjacent structures in order to better understand some of the presenting clinical manifestations of mass lesions in the pituitary region
Brain showing pressure effect of pituitary adenoma - Gross, ventral surface. The pituitary adenoma has been removed to demonstrate local changes due to the mass effect of the tumor. Note the depressed area just anterior to the mammillary bodies,
Brain and pituitary adenoma - Gross, coronal section This specimen shows an advanced pituitary adenoma. The adenoma has grown far beyond the confines of the sella turcica, has markedly distorted the left lateral ventricle, and encases the internal carotid artery
:Craniopharyngeoma
Remnants of the Rathke’s pouch and mostly affect children and young adults and usually benign. But it encroaches on optic chiasm or nerves or rarely on 3rd ventricle or base of brain. 3-4 cm, encapsulated, solid or cystic, with calcification in ѕ of patients.Histologically:Simulate the enamel organ of the tooth, thus called as adamantinomas or ameloblastomas.It looks as cords of stratified squamous epithelium embedded in loose fibrous stroma.Normal Thyroid Gland
Thyroid - NormalNormal resting Thyroid
Hashimoto’s Thyroiditis: Morphology: Grossly: Firm diffuse goiter, with yellow to tan and nodular cut section.Microscopy: Follicle atrophy with lymphocytic infiltration, sometimes in a form of lymphoid follicle formation.Hьrthle cell metaplasia – eosinophilic cells, large enough to be more than 50% of cells.Fibrosis & destruction of follicular tissue.
Hashimoto’s Thyroiditis:
Hashimoto’s Thyroiditis:Hashimoto’s Disease
Anti-thyroglobulin AntibodyAnti- microsomal Autoantibody
DeQuervain's Disease - SAGT Morphology:Patchy microabscess. Lymphocytic and monocytic infiltration. granulomas with giant cells.
DeQuervain's Disease - SAGT
Graves disease:
Thyroid gland is symmetrically enlarged by hypertrophy and hyperplasia, of follicular cells. Cut section, soft, meaty appearance. Microscopically: cells are tall and crowded, causing pseudopapillae (lack fibrovascular core). Colloid is pale, with scalloped margins. Lymphoid infiltration, (mainly T cells), and plasma cells.Graves disease:
Graves DiseaseThe hyperfunctioning follicular epithelium is tall columnar. Papillary infoldings into the follicular lumens result from epithelial proliferation and overcrowding, representing hyperplasia. Peripheral scalloping of the colloid within follicles.
Multinodular goiter, morphology:
Grossly: asymmetric enlargement may reach to 2000 grams. Cut section show multiple nodules contain variable amount of brown gelatinous colloid. Some nodules show cystic degeneration, hemorrhage, fibrosis, and calcification. Microscopy show randomly sized colloid filled follicles lined by flattened cells due to pressure of colloid with focal areas of hyperplasia, fibrosis, microcyst formation and hemosiderin laden macrophages due to old hemorrhage.Colloid goiter: severely enlarged thyroid gland.
Goitre – Iodine Deficiency
Multinodular Goiter with Papillary Carcinoma
Colloid Cysts in MNGMultinodular Goitre
Follicular adenoma:Grossly: Solitary, spherical, encapsulated, lesion, well demarcated from the surrounding thyroid tissue. Average size 3 cm, and can be large up to 10 cm. Color from gray-white, to red-brown, with possible hemorrhage, fibrosis, calcification and cystic changes as in goiter. Well defined capsule demarcates the neoplasm from the surrounding tissue.
Follicular Adenoma
Follicular AdenomaSolitary Adenoma
Microscopy:
Follicular growth pattern, with uniform appearance, differ from adjacent tissues. The epithelial cells of follicles reveal little variation in cell and nuclear morphology. Rare mitotic figures. Intact capsule encircle the tumor.-This neoplastic tissue is very well differentiated, showing follicles containing colloid. -The nuclei are uniform and round with some small nucleoli and no mitotic figures.
Follicular Adenoma
Thyroid CarcinomaType
Age
Spread
Prognosis
Papillary
Young <45y
Lymph
Excellent
Follicular
Middle age
B.V.
Good
Anaplastic
elderly
Local
Poor
Medullary
Elderly familial
All
variable
Papillary carcinoma:
Gross: well defined or infiltrative margins. Solid, or with cystic changes. Fibrosis, calcification or even papillary structures can be seen on cut section. Microscopy: Papillae. Nuclear changes. Psammoma bodies and lymphatic invasion. Variants.This is a lobectomy specimen of thyroid gland showing normal parenchyma, within which is a 2-cm, white, slightly irregular, expansile tumor. No gross papillae are present on the cut surface. The neoplasm is unencapsulated, and it appears to distend and distort the capsule of the thyroid gland without penetrating through it.
Papillary Carcinoma
Microscopy:Branching with fibrovascular stalk, covered by a single to multiple layers of cuboidal epithelial cells. Nuclei of cells contain finely dispersed chromatin, result in optically clear or empty appearance, designed as ground-glass. Also intranulcear inclusions with grooves. Psammoma Bodies are concentrically calcified structures.
Papillary Carcinoma
Papillary Carcinoma-The papillae shown here are covered by cuboidal epithelium. -They have a characteristic nuclei that are large, crowded, and overlapping nuclei with vesicular chromatin, and small nucleoli. -Chromatin clearing (ground-glass "Orphan Annie" nuclei) and irregular nuclear contours with grooves and cytoplasmic pseudoinclusions are hallmark features of papillary thyroid carcinoma.
Medullary carcinoma:
Sporadic cases present as solitary masses, while familial cases present with bilateral and multiple masses. Microscopy: tumors are composed of polygonal to spindle shaped cells, form nets trabeculae, and even follicles. Small anaplastic cells may dominate in some tumors. Acellular amyloid deposits, derived from altered calcitonin polypeptides, seen in stroma.