[doctorF]

A 65-year-old woman has a 6-month history of progressive irritability, palpitations, heat intolerance, frequent bowel movements, and a 6.8-kg (15-lb) weight loss. She has had a neck mass for more than 10 years. 131I scan shows an enlarged thyroid gland with multiple areas of increased and decreased uptake. Which of the following is the most likely diagnosis?

A) Defect in thyroxine (T4) biosynthesis
B) Graves' disease
C) Multinodular goiter
D) Riedel's thyroiditis
E) Thyroid carcinoma
F) Thyroiditis

G) Toxic adenoma

H) Triiodothyronine (T3) thyrotoxicosis

 

[Doc-Yuvi]

should be Graves disease

 

[syedaanaqvi]

multinodular

 

[Seetal]

i tot it was thyroid carcinoma (due the uneven uptake of the radioactive substance)

 

[tomymajor]

answer is c
because multinodular goiter --> heterogenous appearance because there is pathches of increased the upthake representing the pathological areas surrounded by normal tissue which not take iodine
* Toxic adenoma -> single patch of increased uptake
* Graves" --> homogenous increased uptake
* Thyroiditis and carcinoma --- > show decreased uptake
and note that you can know the percentage of uptake by the gland

 

[Seetal]

oh ic.. thanks

answer is c
because multinodular goiter --> heterogenous appearance because there is pathches of increased the upthake representing the pathological areas surrounded by normal tissue which not take iodine
* Toxic adenoma -> single patch of increased uptake
* Graves" --> homogenous increased uptake
* Thyroiditis and carcinoma --- > show decreased uptake
and note that you can know the percentage of uptake by the gland

thanks for the explanation. but i have read that thyroid cancer can uptake radioactive iodine and incidentally it is used to treat thyroid cancer. in fact thyroid cancer is very treatable unless the patient waits till it gets bigger and worse. it is very treatable because the cancer is very radio-sensitive. radiotherapy is highly successful for thyroid cancer.... ryte?

and if the answer was multinodular, wont the physical examination say multinodular mass? this just says 'A' mass.

 

[Seetal]

u know what....

there are multiple areas of decreased and increased Iodine uptake. so which means there are cold and hot nodules. and these could point to multinodular.

im still leaning at thyroid cancer because i have seen pictures (and real cases) of people who leave their multinodular mass for over 5 years and it is HUGE (something worth mentioning in the physical exam). but with thyroid cancer, the mass will not necessarily get terribly huge. it may just as well look like a hypothyroid (Goiter) mass and the distinguishing factor then would be the symptoms.

this is a good question right here!! (its making me think)

 

[tomymajor]

Etiology Fractional 24-Hour Radioiodine Uptake Thyroid Scan Appearance Graves' disease 35–95% Diffuse increased homogeneous uptake; visible pyramidal lobe extending from the isthmus Toxic adenoma 20–60% Solitary focus of intense uptake; suppression of uptake in the remainder of the thyroid Toxic multinodular goiter 20–60% Patchy heterogeneous foci of increased uptake interspersed with regions of diminished uptake Subacute thyroiditis 0–2% Minimal to absent uptake Autoimmune thyroiditis 0–2% Minimal to absent uptake; patchy heterogeneous uptake during recovery Iodine-induced hyperthyroidism 0–2% Minimal to absent uptake Exogenous thyroid hormone intoxication 0–2% Minimal to absent uptake Metastatic differentiated thyroid cancer 0–5% Focal uptake in metastases TSH-secreting pituitary adenoma 30–80% Diffuse increased homogeneous uptake

 

[Seetal]

Thank you dr. tonymajor for yr post. Did u get that from a research? here's what i got from the internet (focus on the bolded sentence):

Thyroid neoplasm or thyroid cancerusually refers to any of four kinds of malignant tumors of the thyroid gland: papillary, follicular, medullary or anaplastic.Most patients are 25 to 65 years of age when first diagnosed; women are more affected than men.Papillary and follicular tumors are the most common. They grow slowly and may recur, but are generally not fatal in patients under 45 years of age. Medullary tumors have a good prognosis if restricted to the thyroid gland and a poorer prognosis if metastasis occurs. Anaplastic tumors are fast-growing and respond poorly to therapy.
Thyroid nodules are diagnosed by ultrasound guided fine needle aspiration (USG/FNA) or frequently by thyroidectomy (surgical removal and subsequent histological examination). As thyroid cancer can take up iodine, radioactive iodine is commonly used to treat thyroid carcinomas, followed by TSH suppression by high-dose thyroxine therapy.

....what do u think?

 

[tomymajor]

i will see and answer

 

[Seetal]

paging dr.F... u still havent given the answer for this question. its killing me!!

 

[doctorF]

o o i just forgot to post answer... sorry dr. seetal...

actually its an nbme ques so i too can only use my logic to it.....

in Goljan's rr it's written that I131 uptake is increased in graves disease and toxic nodular goitre only (hot nodule) whereas in thyroiditis, cysts, adenoma and cancer there is no uptake (cold nodule)

so considering this knowledge in mind.... i personally think that un even uptake shoulg be multi- nodular goitre...

i hope i am right in explaining:happy:

 

[Seetal]

o o i just forgot to post answer... sorry dr. seetal...

actually its an nbme ques so i too can only use my logic to it.....

in Goljan's rr it's written that I131 uptake is increased in graves disease and toxic nodular goitre only (hot nodule) whereas in thyroiditis, cysts, adenoma and cancer there is no uptake (cold nodule)

so considering this knowledge in mind.... i personally think that un even uptake shoulg be multi- nodular goitre...

i hope i am right in explaining:happy:

ok..:happy: thank u. that helps. but damn im still a lil unconvinced because cancer can take up I131 too. perhaps its not as much. hmm....

perhaps i should stop analyzing it too much and just stick to goljan information (although goljan has had misprints before)..

no im gonna stop analyzing. fine! the answer is multinodular due uneven uptake of I131. and cancer DOESNT take up I131. !!!!

 

[khanar]

There's a post about this

Guys,

There's a nice post by Rasheed who explained everything about Thyroid Iodine uptake
here' the link
http://www.usmle-forums.com/usmle-s...dioactive-iodine-uptake-thyroid-diseases.html

Go and read and it will solve your problems I think

 

[hana]

When you want to post a question please always mention that the question is from NBME in the title!