Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
103 Cards in this Set
- Front
- Back
|
Primary cause: of Hypothyroidism
|
failure of thyroid gland to secrete hormone
|
|
|
Secondary causes: of Hypothyroidism
|
failure of pituitary gland to secret TSH or hypothalamus to secrete TRH
|
|
|
TSH stimulates pituitary thyroid _____
|
T4- 5 deiodinase activity
Above stimulates pituitary gland to release additional T3 |
|
|
Heart problems assoc with Hypothyroidism
|
Heart: myxedematous heart disease: decreased contractility, cardiac enlargement, pericardial effusion, decreased pulse, decreased cardiac output
|
|
|
GI probs assoc with Hypothyroidism
|
achlorhydria, decreased intestinal transit with gastric stasis
|
|
|
Sexual dys funcs of Hypothyroidism
|
Delayed puberty, anovulation, amenorrhea, infertility
|
|
|
Nutritional problems with Hypothyroidism
|
Hypercholesterolemia with increased levels of LDL
Insulin resistance |
|
|
Classic Signs & Symptoms of Hypothyroidism
|
Cold intolerance
Puffiness Decreased sweating Coarse skin Above reported in 90-97% of patients, more common in elderly, 50-64% in younger pts. |
|
|
Definition of Myxedema
|
Severe form of hypothyroidism associated with:
Altered mental status Hypothermia Bradycardia |
|
|
Myxedema coma: occurs in pts with myxedema who are subjected to ________
|
external stress
|
|
|
Worldwide, ________remains as foremost cause of hypothyroidism
|
iodine deficiency
|
|
|
In the US and other areas of adequate intake, _______is most common cause of hypothyroidism
|
autoimmune thyroid disease
|
|
|
Most Common Cause of Acquired Hypothyroidism
|
Most frequent cause is autoimmune thyroiditis
Up to 95% of affected pts have thyroid autoantibodies (antimicrosomal & antiperoxidase, most common) |
|
|
Up to ___% of post-partum women develop lymphocytic thyroiditis
|
10
|
|
|
Up to 10% of post-partum women develop lymphocytic thyroiditis
With women with type 1 diabetes, the percentage rises to ___% |
25
|
|
|
High titers of _______antibodies reported as 97% sensitive and 91% specific for post-partum autoimmune thyroid disease
|
anti-TPO
|
|
|
Hypothyroidism associated with the following drugs:
|
Amiodarone
Interferon alpha Thalidomide Stavudine |
|
|
Radioactive Iodine (RAI) for treatment of Graves disease generally results in permanent hypothyroidism within (how long) after therapy
|
one year
(Frequency much lower in pts with toxic nodular goiters and solitary “hot” nodules) |
|
|
A solitary thyroid nodule is detected by palpation
A more direct approach to determine the nature of the nodule is the ______ |
fine needle aspirate
|
|
|
Thyroid gland, radionuclide scan, solitary cold nodule
|
?
|
|
|
Thyroid gland, radionuclide scan, cold nodule
|
?
|
|
|
Thyroid gland, radionuclide scan, multiple cold nodules
|
?
|
|
|
Nearly all of the cold nodules, when removed, have proven to be _____(benign or malig).
|
benign
|
|
|
Remember: Nearly all solitary thyroid nodules are ____.
|
cold
|
|
|
Of the cold solitary nodules, only 10% are _______
|
malignant
|
|
|
Prior to the introduction of FNA, the decision to remove a solitary nodule because it was cold, depended on clinical factors, such as, ____ (4)
|
sex, palpatory findings, family history, exposure to radiation
|
|
|
Thyroid gland, FNA, follicular cells, Wright stain
|
?
|
|
|
The reliability of the FNA resides in the ______
|
competency of the aspirator in obtaining a good specimen
(The aspirate should then be interpreted by an equally competent pathologist) |
|
|
FNA is reliable in the detection of papillary, medullary & anaplastic carcinomas.
However, with ______ carcinomas, FNA is less dependable |
follicular
|
|
|
Thyroid gland, unifocal medullary carcinoma of sporadic type
|
?
|
|
|
Thyroid gland, papillary carcinoma
|
?
|
|
|
Thyroid gland, follicular adenoma
|
?
|
|
|
Thyroid gland, follicular carcinoma in nodular goiter
|
?
|
|
|
A solitary nodule which is more active in concentrating radionuclide and results in a ____ nodule, usually with suppression of the remainder of the thyroid parenchyma
|
“hot”
|
|
|
The hot nodule can be the cause of ____
|
hyperthyroidism
|
|
|
Thyroid gland, solitary hot nodule, with suppression of remainder of gland
|
?
|
|
|
Thyroid gland, multiple hot nodules, nodular goiter
|
?
|
|
|
Thyroid gland, radionuclide scan, multiple hot nodules
|
?
|
|
|
The consensus is that solitary hot nodules are nearly all benign.
However, they can be the cause of _____ |
hyperthyroidism
|
|
|
Thyroid Neoplasms
Benign: called what? |
adenoma
|
|
|
Thyroid Neoplasms
Carcinomas: (4) |
Papillary
Follicular Medullary Anaplastic |
|
|
Thyroid Neoplasms
another malignant type (not carcinoma) |
Malignant lymphoma
|
|
|
What Thyroid Neoplasm?
Solitary nodule Normal or goitrous background Encapsulated Interior of adenoma, differs histologically from surrounding parenchyma |
Adenoma
|
|
|
Thyroid gland, follicular adenoma
|
?
|
|
|
Follicular adenoma
|
?
|
|
|
What type of thyroid neoplasm?
A well demarcated nodule in one lobe. The remainder of the thyroid gland appears normal, or it may have changes of a nodular goiter |
Follicular adenomas
|
|
|
Follicular adenomas usually do not develop into ______
|
follicular carcinomas
|
|
|
What type of carcinoma?
Solitary nodule, in background of normal parenchyma More common in iodine-sufficient areas Affects any age, not unusual in children or young adults Predisposing factors: radiation is the most important factor Not encapsulated, well demarcated Invasive microscopically Prone to metastasize to regional lymph nodes Distant metastases to lungs and bones |
Papillary Carcinoma
|
|
|
Cellular
No nuclear pleomorphism, no increased mitoses No vascular or capsular invasion in some cases, like this one, if invasive growth were present, a diagnosis of well differentiated follicular carcinoma or minimally invasive follicular carcinoma would be made |
?
|
|
|
Usual papillary carcinoma
Size, 2 cm Well demarcated but not encapsulated when viewed microscopically |
?
|
|
|
Papillae, papillary carcinoma
Papillae present Psammoma bodies, laminated & calcified Nuclear changes Clear nuclei Nuclear grooves (nuclear membrane folds) Intranuclear inclusions (of cytoplasm) |
?
|
|
|
Psammoma body, papillary carcinoma
|
?
|
|
|
Psammoma body in smear
of aspirated material |
?
|
|
|
.
|
?
|
|
|
Clinical Features of papillary carcinoma
|
Presence of thyroid nodule
Aspiration cytology: should be diagnostic Distant metastases: recognized in radiographs or total body radionuclide scans Palpatory findings may be suggestive |
|
|
Thyroid gland, FNA, papillary carcinoma
|
?
|
|
|
Papillary carcinoma, follicular variant. Note: nuclear changes
|
?
|
|
|
Treatment of pap carcinoma
|
Thyroidectomy, ranging from lobectomy to total thyroidectomy; Lymph node dissection, when indicated
Postoperative RAI, when indicated |
|
|
Prognostic Factors of pap carcinoma
|
Age: the older the patient the worse the prognosis. Children & adolescents associated with a good prognosis
Metastases: distant metastases, i.e., to lung and/or bones predict a bad prognosis. However, metastases to regional lymph nodes does not Extension of neoplasm across the capsule of the thyroid gland forebodes a bad prognosis Size: the larger the tumor the worse the prognosis Metastases to regional lymph nodes do not affect prognosis |
|
|
Lymph node, metastatic papillary carcinoma of thyroid gland
|
?
|
|
|
Papillary thyroid carcinoma
Invading adjacent skeletal muscle |
?
|
|
|
By definition, smaller than 1 cm
Like all papillary carcinomas, tumors can be bilateral, multifocal Such tumors, previously considered as metastatic foci, now accepted as primary lesions Easily metastasizes to regional lymph nodes Early metastases to regional lymph nodes Not unusual for pt to present with enlarged lymph nodes without a palpable thyroid lesion |
Papillary Microcarcinoma
|
|
|
US incidence: of Papillary Microcarcinoma
|
6-9%
With such high frequencies, the rate of clinically significant thyroid cancers should be higher, but it is not |
|
|
Papillary microcarcinoma, note invasive borders
|
?
|
|
|
Thyroid gland, multiple foci, papillary y carcinoma.
?.Intrathyroidal metastasis or multiple primary neoplasms |
?
|
|
|
Papillary Carcinoma Predisposing Factors
|
There is only one predisposing factor and that is radiation.
|
|
|
Thyroid Carcinoma:
A rate of _?_%, in a population exposed to radiation for benign conditions: enlarged thymus, tinea capitis, chronic sinusitis. This rate is for an American population |
9
|
|
|
Radiation and Chernobyl:
Genetic studies reveal that a large proportion of thyroid glands showed rearrangements of ______ type. |
RET/PTC3
|
|
|
Chernobyl Accident:
majority were _____ carcinomas |
papillary
|
|
|
RET protooncogene has become a factor in developing familial forms of ______ carcinoma
|
medullary
|
|
|
In medullary carcinomas, germline point mutations of ____ are involved
|
RET
|
|
|
RET also has a role in ____ carcinomas.
|
papillary
|
|
|
The changes are gene rearrangements resulting in oncogenes, RET/PTC1 to _____.
|
RET/PTC4
|
|
|
____-more common in irradiated thyroid glands from Chernobyl
|
RET/PTC3
|
|
|
What carcinoma?
No distinctive histology like papillae, nuclear changes or psammoma bodies Encapsulated tumors with well developed capsules Most tumors, well-differentiated with well formed neoplastic follicles May be difficult to differentiate from follicular adenoma |
Follicular Carcinoma
|
|
|
2 divisions of Follicular Carcinoma
|
minimally or markedly invasive follicular carcinomas
|
|
|
Follicular Carcinoma:
Unlike papillary carcinomas, do not usually metastasize to ____ |
lymph nodes
(Prefers hematogenous spread to bones and lungs) |
|
|
Follicular Carcinoma:
Usually arise in glands involved by _____ goiters |
multinodular
|
|
|
Gross and microscopic look of Markedly invasive follicular carcinoma
|
Gross: diffuse infiltration of thyroid parenchyma or blood vessels by tumor
Microscopic: breach of capsule with extension of tumor into thyroid parenchyma and invasion of larger blood vessels |
|
|
Follicular Carcinoma Clinical Features
|
Older females, with nodular goiter, perhaps, with a dominant nodule
Usually euthyroid Distant metastases identified by chest x-ray films and radionuclide total body scans |
|
|
Predisposing Factors for Follicular Carcinoma
|
No known predisposing factors, except for the possibility of iodine deficiency and nodular goiters
|
|
|
Prognostic Factors for Follicular Carcinoma
|
Like papillary carcinomas, age is a factor
Post-menopausal women harbor more aggressive tumors |
|
|
Treatment for Follicular Carcinoma
|
Thyroidectomy: from lobectomy to total thyroidectomy
Radioactive iodine, postoperatively, when indicated. Survival rate is worse than for papillary carcinomas |
|
|
Medullary Carcinoma originates from __-cells.
|
C
|
|
|
Normal secretory product of Medullary Carcinoma
|
calcitonin
|
|
|
Multiple endocrine neoplasia syndromes assoc with 20% Medullary carcinoma
|
MEN IIa
MEN IIb |
|
|
no stigmata of MEN II
Most difficult to detect Most benign of medullary carcinomas |
Familial Medullary Thyroid Carcinoma
|
|
|
Medullary carcinoma
Pheochromocytomas and/or adrenal medullary hyperplasia, bilateral, or mixtures of both Parathyroid hyperplasia with hyperparathyroidism – 30% of patients |
Multiple Endocrine Neoplasia IIa
|
|
|
Medullary carcinoma
Bilateral pheochromocytomas or adrenal medullary hyperplasia or mixtures of both Other stigmata: facies, mucosal neuromas, colonic ganglioneuromatosis, Marfanoid habitus, hyperextensible joints, hypertrophic corneal nerves Few associated with Hirschsprung disease No parathyroid hyperplasia |
Multiple Endocrine Neoplasia IIb
|
|
|
Medullary Carcinomas: Sporadic vs Familial Forms
|
Sporadic: unilateral and unifocal lesion, well demarcated, poorly encapsulated
May be associated with lymph node metastases that may be large and bulky. Familial: bilateral, multifocal, well-demarcated, poorly encapsulated |
|
|
Sporadic or non-familial medullary carcinoma
|
?
|
|
|
Thyroid gland, bilateral medullary carcinomas, of familial type
|
?
|
|
|
Two types of C-cell hyperplasia
|
Physiologic – associated with other lesions, like AIT, hyperparathyroidism
Pre-neoplastic-- associated with and gives rise to medullary carcinomas |
|
|
Screening for Medullary Carcinomas
|
Present method: screen for RET protooncogene
|
|
|
method now used to follow pts postoperatively for persistent or recurrent Medullary Carcinomas
|
intravenous injection of pentagastrin and calcium
Positive test: elevated serum calcitonin |
|
|
treatment of Medullary Carcinomas
|
Total thyroidectomy with dissection of regional lymph nodes, when indicated
Thyroid gland must be totally removed because any remaining C-cell is a potential source for carcinoma When post-operative levels of calcitonin remain elevated, this indicates that pt is harboring more neoplasm, most likely in form of metastases |
|
|
prognosis of Medullary Carcinomas
|
FMTC – best prognosis
MEN IIa – next best MEN IIb – worst Sporadic – 50% survival rate at 5 yrs. |
|
|
pathology of MEN IIb
|
Microscopic: small neuroendocrine cells
Therefore: stain like neuroendocrine cells: Chromogranin + Neuron-specific enolase + Synaptophysin + Stains for calcitonin, CEA Cells are versatile and may produce other peptides: CEA, VIP, serotonin, ACTH Associated C-cell hyperplasia is found in familial forms Amyloid is regularly produced by tumors |
|
|
Anaplastic carcinoma points
|
Older patients, usually with long histories of goiters
Recent rapid growth of goiters, at times leading to respiratory distress, requiring tracheotomy Large, hard, fixed mass in neck, vicinity of thyroid gland Often, inoperable Poor response to radiation or chemotherapy |
|
|
Anaplastic Carcinoma – Pathology
|
Gross: extensively invasive, large white mass, may or may not see origin from thyroid gland.
Microscopic: Undifferentiated neoplasm, composed of spindle and giant cells, differentiated carcinomas often found within anaplastic areas. |
|
|
Anaplastic tumors, often arise from differentiated carcinomas, most commonly ______ carcinomas
|
follicular
|
|
|
Anaplastic carcinomas, very rare in US, probably due to iodine sufficiency, lack of nodular goiters and _____ carcinomas
|
follicular
|
|
|
Clinical Features
of anaplastic carcinoma |
Typically women
Older pts. (57-67 yrs) Rapidly enlarging neck mass Hoarseness & dyspnea |
