TYPES OF PITUITARY ADENOMAS identify what prolactenemia 1. Due to pregnancy 2. Due to to lactotroph hyperplasia, stalk effect, drugs, estrogens, renal failure, and hypothyroidism.

1. Physiologic Prolactinemia 2. Pathologic Prolactinemia Treatment includes surgery or bromocriptine

[M] Week 7: Endocrine System - Part 1 Flashcards by Geno Alinsub

What are the parts of endocrine system?

Pituitary gland
Thyroid gland
Parathyroid gland
Endocrine pancreas
Adrenal glands
Pineal gland

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The endocrine signaling mechanism occurs through the action of?

HORMONES

Hormones trigger biochemical signals upon interacting with cell-surface receptors

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Most of the regulation of the endocrine system is through?

feedback inhibition

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Diseases within the endocrine system may be due to three patterns, what are those?

Under-production of hormones
Over-production of hormones
Development of mass lesions

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Small, bean-shaped organ encased by the brain within the sella turcica

Pituitary Gland

It measures 1 cm, and weighs 0.5 grams.
Consists of the anterior and posterior lobe

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Pituitary Gland

Otherwise known as ADENOPHYPOPHYSIS.
It is where most of the hormones that stimulate signaling come from.

Anterioir Lobe

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Pituitary Gland

Match

Somatotrophs
Lactotrophs
Corticotrophs
Thyrotrops
Gonadotrophs

A. Basophils, produce adrenocorticotropic hormone (ACTH), proopiomelanocortin (POMC), melanocyte-stimulating hormone (MSH), endorphins, and lipotropin
B. Basophils, produce thyroid-stimulating hormones (TSH)
C. Acidophils; produce growth hormones (GH)
D. Basophils, produce follicle-stimulating hormone (FSH), and luteinizing hormone (LH)
E. Acidophils, produce prolactin

check niyo nalang pic sa trans

Most of the hormones are released through positive signaling, EXCEPT for prolactin and growth hormone.

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Pituitary Gland

Also known as the NEUROHYPOPHYSIS, as it is a direct continuation of the hypothalamus

Posterior Lobe

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Pituitary Gland

Cells of the posterior pituitary are less than that of the anterior portion, wherein it only consists of what cells

modified glial cells (pituicytes)
axonal processes

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Pituitary Gland

What does posterio lobe of pituitary gland secrets?

ADH controls the excretion of urine or diuresis for the maintenance of blood volume levels.
Oxytocin assists during cervical dilation when giving birth or parturition

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PITUITARY ADENOMAS AND YPERPITUITARISM

What are the most common cause of hyperpituitarism

adenoma arising in the anterior lobe

**Pituitary adenoma **

Adenoma is defined as a benign lesion secreting extra hormones

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what is the morphology of a pituitary adenoma

soft, well-circumscribed with sparse reticulin framework

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TOF

The physical adenoma impinges on the adjacent structures of the brain, and is considered to be 30% invasive

True

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Pituitary adenoma is benighn, what will be shown in the histology?

monomorphic pattern– appearing the same, and with no mitosis

However, a benign adenoma that is impinging and is infiltrating structures within the brain will be treated as a malignant adenoma.

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CLINICAL COURSE OF PITUITARY ADENOMA

Adenomas are diagnosed through:

Stereotactic biopsy
Transphenoidal biopsy–which enters through the nose and punctures the bony sphenoid to reach the sella turcica
Radiation therapies measure the amount of radiation to actually hit the adenoma and lyse the tumor

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What are the types of pituitary adenomas

Prolactinoma
Growth Hormone or Somatotroph Cell Adenomas
Corticotroph Cell Adenomas

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TYPES OF PITUITARY ADENOMAS

this is the most frequent type - comprising 30% of all clinically recognized pituitary adenomas

Prolactinoma

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TYPES OF PITUITARY ADENOMAS

Small to large, expansile tumors
Weakly acidophilic or chromophobe cells
Propensity of dystrophic calcification–psammoma bodies to pituitary stone
Characterized by its efficiency and proportionality.

Prolactinoma

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In prolactinoma this secretes excess prolactine resulting in?

PROLACTENEMIA which may result to amenorrhea, galactorrhea, loss of libido, and infertility

Galactorrhea is defined as the secretion of milk which may be seen in women after giving birth.
Amenorrhea is the absence of menses which may result to infertility.

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TYPES OF PITUITARY ADENOMAS

identify what prolactenemia

Due to pregnancy
Due to to lactotroph hyperplasia, stalk effect, drugs, estrogens, renal failure, and hypothyroidism.

Physiologic Prolactinemia
Pathologic Prolactinemia

Treatment includes surgery or bromocriptine

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TYPES OF PITUITARY ADENOMAS

the second most common type
Manifestations are subtle but large on the diagnosis–meaning that effects are very visible.
Histologic subtypes consist of densely (acidophilic) and sparsely (chromophobe) granulated

Growth Hormone or Somatotroph Cell Adenomas

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Growth Hormone or Somatotroph Cell Adenomas

Bihormonal mammosomatotroph adenomas (acidophilic)
are due to

excess of both GH and prolactin

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Growth Hormone or Somatotroph Cell Adenomas

The persistent hypersecretion of GH may lead to?

hepatic secretion of insulin-like growth factor (IGF-1) or
somatomedin C

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Growth Hormone or Somatotroph Cell Adenomas

The persistent hypersecretion of GH may lead to the hepatic secretion of insulin-like growth factor (IGF-1) or
somatomedin C that may result in

GIGANTISM or ACROMEGALY

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# Growth Hormone or Somatotroph Cell Adenomas If it occurs **BEFORE** the closure of the epiphysis of the long bones, the patient will suffer from

GIGANTISM

# Growth Hormone or Somatotroph Cell Adenomas If it occurs **AFTER** the closure of the epiphysis of the long bones, the patient will suffer from.

ACROMEGALY

# Growth Hormone or Somatotroph Cell Adenoma Diagnosis are confirmed how?

elevated serum GH and IGF-1 levels

# TYPES OF PITUITARY ADENOMAS Excess production of ACTH by functioning corticotroph adenomas leads to adrenal hypersecretion of cortisol and the development of hypercortisolism–also known as the **CUSHING SYNDROME.**

Corticotroph Cell Adenomas

# TYPES OF PITUITARY ADENOMAS * Diagnosed through the presence of **microadenomas**. * Often basophilic (densely granulated), occasionally chromophobe (sparsely) * Periodic acid schiff **(PAS) positive (+)** due to carbohydrate in POMC

Corticotroph Cell Adenomas

# Corticotroph Cell Adenomas When hypercortisolism is due to the excessive production of ?

**ACTH** by the **PITUITARY** it is designated as a CUSHING DISEASE.

# Corticotroph Cell Adenomas If it is due to the excessive production by the **ADRENAL**, it is designated as?

Cushing SYNDROME.

Decreased secretion of pituitary hormones due to hypothalamus or pituitary diseases

Hypopituitarism

A person suffers from hypopituitarism when ____ of parenchyma is lost, absent, or nonfunctional

75%

When accompanied by evidence of posterior pituitary dysfunction in the form of diabetes insipidus, hypopituitarism is almost always of

hypothalamic origin

# OTHER MECHANISMS OF HYPOPITUITARISM Most cases of hypopituitarism arise from destructive processes involving the anterior pituitary, as follows:

1. Tumors and other tumor masses 2. Pituitary surgery or radiation 3. Pituitary apoplexy 4. **Ischemic necrosis and Sheehan syndrome** 5. Rathke cleft cyst 6. Empty sella syndrome (rare) 7. Genetic defects 8. Hypothalamic lesion

# OTHER MECHANISMS OF HYPOPITUITARISM postpartum hypopituitarism caused by necrosis of the pituitary gland, which usually happens in pregnant women.

Sheehan's syndrome

# CLINICAL MANIFESTATIONS OF HYPOPITUITARISM Match 1. GH Deficiency 2. Gonadotropin (GnRH) (LH and FSH) deficiency 3. TSH deficiency 4. ACTH deficiency 5. Prolactin deficiency 6. MSH deficiency A. Amenorrhea and infertility in women; decreased libido, impotence, and loss of pubic and axillary hair in men B. Hypothyroidism C. Failure of postpartum lactation D. Hypoadrenalism E. Pallor F. Pituitary dwarfism

1. F 2. A 3. B 4. D 5. C 6. E

# POSTERIOR PITUITARY SYNDROMES Enumerate all the syndrome mentioned

1. Diabetes Insipidus 2. Secretion of Inappropriately High Levels of ADH

# POSTERIOR PITUITARY SYNDROMES - Characterized by polyuria (same manifestation with Diabetes Mellitus) * Mostly due to a problem with ADH * Causes: head trauma, tumors and inflammatory lesions and surgery of hypothalamus and pituitary;spontaneously * Central, if due to ADH deficiency, or nephrogenic, if due to renal tubular unresponsiveness to ADH

Diabetes Insipidus

# POSTERIOR PITUITARY SYNDROMES - causes resorption of excessive amounts of free water, giving rise to hyponatremia * Serum Na+ is diluted, thus decreased in levels * Causes: ectopic ADH by neoplasms, non-neoplastic diseases of the lung, local injury to hypothalamus or posterior pituitary or both * Signs and Symptoms: hyponatremia, cerebral edema and neurologic dysfunction; total body water increased; blood volume, normal; no peripheral edema

Secretion of Inappropriately High Levels of ADH

* An organ located in the middle of the neck with two bulky lateral lobes, thin isthmus * Arise from evagination of pharyngeal epithelium that descends from foramen cecum as part of thyroglossal duct

Thyroid Gland

What are the two important hormones secreted by the thyroid gland

T3 (triiodothyronine) and T4 (thyroxine)

In the synthesis of the thyroid hormones, the presence of what is required?

**iodine**

What causes the transient hyperplasia

- Puberty - Pregnancy - Stress

Function of Thyroid gland

1. Up-regulation of carbohydrate and lipid catabolism 2. Stimulation of protein synthesis 3. Brain development (1 & 2 increase BMR)

The function of the thyroid gland can be inhibited by a variety of chemical agents, collectively referred to as goitrogens. Because they suppress T3 and T4 synthesis, the level of TSH increases, causing subsequent?

hyperplastic enlargement of the gland (goiter)

The thyroid gland follicles also contain a population of ____ or ____ which synthesize and secrete calcitonin

parafollicular cells or C cells

* **Thyrotoxicosis**: hypermetabolic state due to elevated circulating levels of T3 and T4 (to compensate baba TSH) - due to hyperfunction of thyroid gland

Hyperthyroidism

Most common causes of hyperthyroidism

- diffuse hyperplasia (common, abnout 85%) - hyperfunctional multinodular goiter - hyperfunctional adenoma of thyroid

# CLINICAL FEATURES: HYPERYHYROIDISM Excessive levels of thyroid hormone result in?

- increase in the basal metabolic rate 170 - 200 | eto lang pinatanda ni maam

Laboratory findings that support the diagnosis of hyperthyroidism includes?

**low TSH value** accompanied by an **increase in free T4**

In occasional patients, hyperthyroidism results predominantly from increased circulating levels of ____ In these cases, free T4 levels may be decreased, and direct measurement of **serum T3 is useful.**

T3 (“T3 toxicosis”)

- a condition caused by a structural or functional derangement that interferes with the production of thyroid hormone. - can result from a defect anywhere in the hypothalamic-pituitary-thyroid axis

Hypothyroidism

Identify what classification of hypothyrodism 1. intrinsic thyroid abnormality 2. pituitary and hypothalamic disease

1. Primary 2. Secondary | Primary hypothyroidism can be congenital, autoimmune, or iatrogenic

Types of Hypothyroidism

1. **Congenital Hypothyroidism** (iodine deficiency in the diet.) 2. **Autoimmune Hypothyroidism** (most common cause of hypothyroidism in iodinesufficient areas of the world) 3. **Iatrogenic Hypothyroidism** (surgical or radiation-induced ablatio)

what are the clinical manifestaion of hypothyroidism

1. Creatinism 2. Myxedema

# CLINICAL MANIFESTATIONS OF HYPOTHEROIDISM refers to hypothyroidism that develops in infancy or early childhood

CRETINISM

# CLINICAL MANIFESTATIONS OF HYPOTHEROIDISM Sporadic cretinism is due to

enzyme deficiency ## Footnote Clinical features of cretinism include severe intellectual disability, short stature, coarse facial features, a protruding tongue, and umbilical hernia.

# CLINICAL MANIFESTATIONS OF HYPOTHEROIDISM applied to hypothyroidism developing in the older child or adult.

MYXEDEMA (GULL DISEASE)

# CLINICAL MANIFESTATIONS OF HYPOTHEROIDISM Myxedema is marked by a

slowing of physical and mental activity

# CLINICAL MANIFESTATIONS OF HYPOTHEROIDISM * Early symptoms include generalized fatigue, apathy, and mental sluggishness, which may mimic depression. Speech and intellectual functions are slowed, and patients are listless, cold intolerant, and frequently overweight. * **Reduced cardiac output** probably contributes to shortness of breath and decreased exercise capacity, two frequent complaints. * **Decreased sympathetic activity** results in constipation and decreased sweating.

MYXEDEMA (GULL DISEASE)

Diagnosis of Hypothyroidism are through?

Measurement of the **serum TSH level** is the most sensitive screening test for this disorder

The TSH level is increased in ____ ____ as a result of a loss of feedback inhibition of TRH and TSH production by the hypothalamus and pituitary, respectively

primary hypothyroidism

The TSH level is not increased in persons with hypothyroidism due to?

hypothalamic or pituitary disease

T4 levels are decreased in individuals with?

hypothyroidism

What are the three most common and clinically signioficant subtypes of thyroiditis

1. Hashimoto Thyroiditis 2. Granulomatous (De Quervain) Thyroiditis 3. Subacute Lymphocytic Thyroiditis

- **'Chronic Lymphocytic Thyroiditis’** * autoimmune disease that results in **destruction of the thyroid gland** and **gradual and progressive thyroid failure.** * It is the most common cause of hypothyroidism in areas of the world where **iodine levels are sufficient** * It is most prevalent between **45 and 65 years of age** and is more common in women than in men, with a female predominance of **10:1 to 20:1.** * SIGNIFICANT GENETIC COMPONENT: **Multiple Genes**; **Turner Syndrome** and **Trisomy 21**; Chromosome **6p & 12q**

Hashimoto Thyroiditis

# MORPHOLOGY: HASHIMOTO THYROIDITIS The thyroid is usually?

usually diffusely enlarged.

# MORPHOLOGY: HASHIMOTO THYROIDITIS The capsule is ____, and the gland is well demarcated from adjacent structures The cut surface is?

- Intact - pale, yellow-tan, firm, and somewhat nodular.

# MORPHOLOGY: HASHIMOTO THYROIDITIS There is extensive infiltration of the parenchyma by a

**mononuclear inflammatory infiltrate** Containing small lymphocytes, plasma cells, and well-developed germinal centers

# MORPHOLOGY: HASHIMOTO THYROIDITIS What will be the morphology of thyroid follicles?

**HÜRTHLE CELLS** atrophic and are lined in many areas by epithelial cells with abundant eosinophilic, granular cytoplasm

# MORPHOLOGY: HASHIMOTO THYROIDITIS They are also at increased risk for development of?

extranodal marginal zone B-cell lymphoma (B-cell hodgkin lymphoma)

* ‘De Quervain Thyroiditis ‘ * The disorder is most common between **30 and 50 years of age** and, like other forms of thyroiditis, affects women more often than men. (female:male ratio is 3-5:1)

Granulomatous Thyroiditis

# PATHOGENESIS: GRANULOMATOUS THYROIDITIS Granulomatous thyroiditis is believed to be triggered by a?

viral infection or a post viral inflammatory process ## Footnote stimulates a cytotoxic T-lymphocyte response to one or more thyroid antigens that damages thyroid follicle cells

- **painless** or **silent thyroiditis**, is a presumed autoimmune disease * **Uncommon** cause of hyperthyroidism * Although it can occur at any age, it is most often seen in **middle-aged adults** and is more common in **women**. Some patients transition from hyperthyroidism to hypothyroidism before recovery. * Pathogenesis is still **unknown** * Comes to medical attention due to mild hyperthyroidism, goiter, or both * A similar disease process can occur during the **postpartum** period in up to 5% of women (postpartum thyroiditis)

Subacute Lymphocytic (Painless) Thyroiditis

most common cause of endogenous hyperthyroidism

Graves Disease

Graves Disease is characterozed by a triad of clinical findings, what are those?

1. Hyperthyroidism 2. Infiltrative ophtalmopathy 3. Localized, infiltrative dermopathy, sometimes called pretibial myxedema

What are the genetic factors of grave disease?

- family members - HLA-B8 & -DR3 - CTLA-4 gene polymorphism - chromosome 6p and 20q

# MORPHOLOGY: GRAVES DISEASE What are the main characrterization of grave disease? (highlighted ni maam)

* Too many cells, crowding * Pale, scalloped colloid (prominent)

Enlargement of thyroid (goiter) is most common manifestation of?

THYROID DISEASE!!!! | bobo kaba kung dimo nasagot

Impaired synthesis of hormone caused by dietary iodine deficiency leads to compensatory rise in TSH, which, in turn causes hypertrophy and hyperplasia of follicular cells→ goiter→?

euthyroidism

Congenital biosynthetic defect or endemic iodine deficiency results in

goitrous hypothyroidism

Enlargement proportional to duration of thyroid hormone (Deficiency or Efficiency)

Deficiency

Goiter can be divided into 2 types, what are those:

diffuse nontoxic and multinodular

# Goiter <3 - causes enlargement of the **entire gland** without producing nodularity. * Because the enlarged follicles are filled with colloid, the term **colloid goiter** has been applied to this condition. * This disorder occurs in both an **endemic** and a **sporadic** distribution

Diffuse Nontoxic (Simple) Goiter

# Endemic or Sporiadic Goiters occurs in geographic areas where the soil, water, and food supply contain low levels of iodine. The term ____ is used when goiters are present in **more than 10%** of the population in a given region.

Endemic goiter

# Endemic or Sporiadic Goiters occurs less frequently than does endemic goiter. There is a striking female preponderance and a peak incidence at puberty or in young adult life.

Sporadic goiter

# Goiter <3 - produce the most **extreme thyroid enlargements** and are more frequently *mistaken for neoplasms* than any other form of thyroid disease * Occurs when the simple goiter **involutes or increases in size**, and it may produce hemorrhage and scarring with calcification. * Due to **recurrent episodes** of hyperplasia and involution of simple goiter

Multinodular Goiter

# Multinodular or Diffuse nontoxic - MORPHOLOGY * It may be hanging on the thoracic cavity that may compress other structures causing difficulty breathing, swallowing, hoarseness of voice, * **Multilobulated, asymmetrically enlarged glands** * Intrathoracic or plunging goiter -goiter grows behind the sternum * Irregular nodules, variable amount of colloid * Hemorrhage, fibrosis, calcification, cyst * Colloid-rich follicles flattened, inactive epithelium, areas of hypertrophy, hyperplasia

MULTINODULAR GOITER

# Multinodular or Diffuse nontoxic - MORPHOLOGY * Hyperplastic phase or colloid involution phase; abundant colloid flattened, cuboidal epithelium * Enlargement of the thyroid gland with **abundant colloid flattened epithelium**

DIFFUSE NONTOXIC GOITER

* Comprise only 1.5% of all cancers * Comprises only 1.5% of thyroid cancer * Mostly adults, papillary Ca may be in childhood * Female, early and middle-adult years * Mostly well-differentiated * Most are derived from thyroid follicle epithelium (except medullary carcinoma, which is derived from parafollicular C cells)

Thyroid Carcinoma

# Thyroid Carcinoma - Major Subtypes 1. Papillary carcinoma 2. Follicular carcinoma 3. Medullary carcinoma 4. Poorly differentiated and anaplastic (undifferentiated) carcinoma C. 5% A. >85% D. <5%) B. 5-15%

1. A 2. B 3. C 4. D

# Thyroid **Most common form** of thyroid cancer and is said to be indolent, accounting for nearly **85% of primary thyroid** malignancies in the United States

Papillary Carcinoma

# Thyroid Cancer Named by the appearance of the tumor; some sections would appear like papillae or finger-like projections. Branching papillae have a fibrovascular stalk covered by a single to multiple layers of cuboidal epithelial cells.

Papillary Carcinoma

# Thyroid Cancer * They are lined by cells with **empty nuclei or grooved nuclei** (MOST COMMON FINDING) * Due to the nuclei with finely dispersed chromatin and an optically clear or empty appearance, it is sometimes called as **Orphan Annie eye nuclei**

Papillary Carcinoma

# Thyroid Cancer - Papillary Carcinoma Concentrically calcified structures termed ____ ____ are often present, usually within the cores of papillae strong indication that it is a papillary carcinoma, when present in fine-needle aspiration material

psammoma bodies

# Thyroid Cancer One of the nicest course of carcinoma

˚ʚ♡ɞ˚˚ʚ♡ɞ˚˚ʚ♡ɞ˚˚ʚ♡ɞ˚ ‪‪❤︎‬ **Papillary Carcinoma** ‪‪❤︎‬ ˚ʚ♡ɞ˚˚ʚ♡ɞ˚˚ʚ♡ɞ˚˚ʚ♡ɞ˚ ## Footnote Just like any other malignancies, when caught late, then the prognosis is not good

# Thyroid Cancer - account for **5% to 15% of primary thyroid cancers**, but are more frequent in areas with dietary *iodine deficiency*, where they constitute 25% to 40% of thyroid cancers. * It is more common in **women (1:3)**, in older age groups compared to papillary carcinoma; its peak incidence is between 40s to 60s

Follicular Carcinoma

# Thyroid Cancer - Composed of **neuroendocrine neoplasms** derived from the parafollicular cells (C cells). o They account for 5% of thyroid neoplasms * They secrete **calcitonin**, which is measured for diagnosis and post-operative follow-up; other polypeptide (PP) hormones such as serotonin, ACTH, and vasoactive intestinal peptide (VIP)

Medullary Carcinoma

what to remember about the morphology of MEDULLARY CARCINOMA

- Formation of nests, trabeculae, or follicles by polygonal to spindle-shaped cells in medullary carcinomas - **Acellular amyloid deposits** in the stroma

# Thyroid Cancer - Undifferentiated tumors of thyroid follicular epithelium * Aggressive tumors with almost 100% mortality rate * Mean age: 65 y/o * 50%, history of multinodular goiter * 20%, history of differentiated carcinoma * 20-30%, with concurrent differentiated cancer, frequently papillary CA * **one of the most aggressive** cancers known; in most cases death occurs in less than 1 year.

Anaplastic Carcinoma

# Thyroid Carciinoma - Morphology Anaplastic, Medullary, Follicular, or Papillary 1. Orphan Annie eye nuclei 2. Minimally and Widely invasive follicular carcinoma 3. nests, trabeculae, or follicles by polygonal to spindle-shaped cells in medullary carcinomas 4. Large, pleomorphic giant cells, Spindle cells with sarcomatous appearance, Mixed spindle and giant cells, and Small cells

1. Papillary 2. Follicular 3. Medullary 4. Anaplastic