question: the difference between fine-needle non-aspiration cytology (FNNAC) and fine-needle aspiration cytology (FNAC) of thyroid lesions
comment: You have a drink in a glass. You take a straw put it in the glass. Cover the top of the straw and remove the straw. Let go your finger over a slide. Look under the microscope. That's FNNAC Take the straw and with your mouth pull up some liquid. Empty that liquid onto a few slides. Look under the microscope. That's FNAC.
passages: Fine Needle Aspiration Cytology (FNAC) is a cheap, simple, and safe method in obtaining cytological specimens for diagnosis by using a needle and a syringe. The "Bethesda System for Reporting Thyroid Cytopathology" is the system used to report whether the thyroid cytological specimen is benign or malignant. It can be divided into six categories:
  
  Section::::Diagnosis.:Blood tests.
   The "Bethesda System for Reporting Thyroid Cytopathology" is the system used to report whether the thyroid cytological specimen is benign or malignant on fine-needle aspiration cytology (FNAC). It can be divided into six categories:
  
  Repeated FNAC is recommended for Category I, followed by clinical follow-up in Category II, repeat FNAC for Category III, and lobectomy for Category IV, near total-thyroidectomy/lobectomy for Category V, and near total thyroidectomy for Category VI. The risk of malignancy in a malignant FNAC report is 93.7% while for a suspicious FNAC report, it is 18.9%.
  
  Section::::See also.
  
  BULLET::::- American Society for Clinical Pathology
  
  Section::::External links.
   BULLET::::- Suspicious for Malignancy (Bethesda category V).
  
  It is important to note that a NIFTP diagnosis cannot be made on the basis fine needle aspiration alone. Evaluation of a surgical resection specimen is required to rule out invasive growth. If molecular studies are applied to the fine needle aspiration material, an "RAS" mutation is the most common identification.
  
  Section::::Diagnosis.:Pathology findings.
  
  Section::::Diagnosis.:Pathology findings.:Size.
   Section::::Procedures.:Diagnostic techniques.
  
  BULLET::::- Fine needle aspiration: biopsy with a fine needle trying to obtain tissue diagnosis by examining the tumour cells.
  
  BULLET::::- Core needle biopsy: similar to fine needle aspiration, only involving the use of larger needles to excise the tissue.
  
  BULLET::::- Vacuum assisted biopsy: similar to core needle aspiration but using vacuum assistance to gather the sample. Vacuum assisted breast biopsy may provide a high diagnostic yield in case of breast tumours.
  
  Section::::Procedures.:Ablation techniques.
   First-generation TSH assays were done by radioimmunoassay and were introduced in 1965. There were variations and improvements upon TSH radioimmunoassay, but their use declined as a new immunometric assay technique became available in the middle of the 1980s. The new techniques were more accurate, leading to the second, third, and even fourth generations of TSH assay, with each generation possessing ten times greater functional sensitivity than the last. Third generation immunometric assay methods are typically automated. Fourth generation TSH immunometric assay has been developed for use in research.
  
  Section::::Thyroid-stimulating hormone.:Current status.
   BULLET::::- Ultrasonographic examination often shows the abscess or swelling in thyroid
  
  BULLET::::- Gallium scan will be positive
  
  BULLET::::- Barium swallow will show fistula connection to the piriform sinus and left lobe
  
  BULLET::::- Elevated white blood cell count
  
  BULLET::::- Elevated erythrocyte sedimentation rate
  
  BULLET::::- Fine-needle aspiration
  
  Section::::Treatment.
   Fine needle aspiration has the advantage of being a brief, safe, outpatient procedure that is safer and less expensive than surgery and does not leave a visible scar. Needle biopsies became widely used in the 1980s, but it was recognized that the accuracy of identification of cancer was good, but not perfect. The accuracy of the diagnosis depends on obtaining tissue from all of the suspicious areas of an abnormal thyroid gland. The reliability of fine needle aspiration is increased when sampling can be guided by ultrasound, and over the last 15 years, this has become the preferred method for thyroid biopsy in North America.
   Fine needles are 23 to 27 gauge. Because needles as small as 27 gauge can almost always yield diagnostic material, FNAC is often the least injurious way to obtain diagnostic tissue from a lesion. Sometime a syringe holder may be used to facilitate using one hand to perform the biopsy while the other hand is immobilizing the mass. Imaging equipment such as a CT scanner or ultrasound may be used to assist in locating the region to be biopsied.
  
  FNAC has become synonymous to interventional cytology.
  
  Section::::Cell collection.:Intervention cytology.:Sediment cytology.
   This involves extracting a fluid sample through a thin needle inserted into the nodule (mass), and creating slides that are then interpreted by a cytopathologist. These tumors are difficult to interpret. As a result, it is likely that over 90% of these tumors will be put into one of the indeterminate categories of The Bethesda System for Reporting Thyroid Cytopathology: Recommended Diagnostic Categories The indeterminate categories of Bethesda include:
  
  BULLET::::- Atypia of Undetermined Significance or Follicular Lesion of Undetermined Significance (Bethesda Category III);
  
  BULLET::::- Follicular Neoplasm or Suspicious for a Follicular Neoplasm (Bethesda Category IV);
   Clinical evaluation is usually done with ultrasound studies, which will usually show a solid, well demarcated mass, often showing limited shadowing (hypoechoic). Depending on the specific character on ultrasound and other clinical findings, a fine needle aspiration is often performed.
  
  Section::::Diagnosis.:Fine needle aspiration.
   The MACIS system of estimating the prognosis of papillary thyroid cancer was developed by Clive S. Grant at the Mayo Clinic, and was based on careful evaluation of a large group of patients. It is probably the most reliable staging method available.
  
  It assigns scores to the main factors involved, and uses the sum of this score to calculate the prognosis:
  
  Most patients fall into the low-risk category (MACIS score less than 6.0) and are cured of the cancer at the time of surgery.
   BULLET::::- () Unilateral thyroid lobectomy
  
  BULLET::::- () Other partial thyroidectomy
  
  BULLET::::- () Complete thyroidectomy
  
  BULLET::::- () Substernal thyroidectomy
  
  BULLET::::- () Excision of lingual thyroid
  
  BULLET::::- () Excision of thyroglossal duct or tract
  
  BULLET::::- () Parathyroidectomy
  
  BULLET::::- () Other operations on thyroid (region) and parathyroid
  
  BULLET::::- () Operations on other endocrine glands
  
  BULLET::::- () Exploration of adrenal field
  
  BULLET::::- () Diagnostic procedures on adrenal glands, pituitary gland, pineal gland, and thymus
  
  BULLET::::- () Partial adrenalectomy
  
  BULLET::::- () Bilateral adrenalectomy
  
  BULLET::::- () Other operations on adrenal glands, nerves, and vessels
  
  BULLET::::- () Operations on pineal gland
  
  BULLET::::- () Hypophysectomy
   Fine-needle aspiration, or fine-needle aspiration cytology (FNAC), involves use of a needle attached to a syringe is to collect cells from lesions or masses in various body organs by microcoring, often with the application of negative pressure (suction) to increase yield. FNAC can be performed under palpation guidance (i.e., the clinician can feel the lesion) on a mass in superficial regions like the neck, thyroid or breast; FNAC may be assisted by ultrasound or CAT scan for sampling of deep-seated lesions within the body that cannot be localized via palpation. FNAC is widely used in many countries, but success rate is dependent on the skill of the practitioner. If performed by a pathologist alone, or as team with pathologist-cytotechnologist, the success rate of proper diagnosis is higher than when performed by a non-pathologist. This may be due to the pathologist's ability to immediately evaluate specimens under a microscope and immediately repeat the procedure if sampling was inadequate.
   Thyroid ultrasonography is the modality of choice for thyroid evaluation. Yet, focal and diffuse thyroid abnormalities are commonly encountered during the interpretation of computed tomography (CT) exams performed for various clinical purposes. For example, CT often detects incidental thyroid nodules (ITNs). It plays an important role in the evaluation of thyroid cancer.
  
  Section::::Introduction.
   Section::::Genetics.:Markers.
  
  While the increased serum concentration of calcitonin is not harmful, it is useful as a marker which can be tested in blood.
  
  A second marker, carcinoembryonic antigen (CEA), also produced by medullary thyroid carcinoma, is released into the blood and it is useful as a serum or blood tumor marker. In general, measurement of serum CEA is less sensitive than serum calcitonin for detecting the presence of a tumor, but has less minute to minute variability and is therefore useful as an indicator of tumor mass.
  
  Section::::Diagnosis.
   A medical biopsy refers to the obtaining of a tissue sample for examination under the microscope or other testing, usually to distinguish cancer from noncancerous conditions. Thyroid tissue may be obtained for biopsy by fine needle aspiration (FNA) or by surgery.
   In 1978, Kopen Wang and colleagues at Johns Hopkins Hospital described the use of transbronchial needle aspiration (TBNA) through a rigid bronchoscope to diagnose a paratracheal mediastinal mass. Following the advent of endobronchial ultrasound (EBUS), which first became available in the early 21st century, EBUS-TBNA swiftly replaced mediastinoscopy as the first-line in mediastinal staging for lung cancer. With these developments, interventional pulmonology became much more firmly established on the map of distinct subspecialties. 
   The main characteristics that can help distinguish a benign vs. malignant (cancerous) thyroid nodule on ultrasound are as follows:
  
  Although ultrasonography is a very important diagnostic tool, this method is not always able to separate benign from malignant nodules with certainty. In suspicious cases, a tissue sample is often obtained by biopsy for microscopic examination.
  
  Section::::Diagnosis.:Radioiodine scanning and uptake.
   BULLET::::- Thyroid cysts: The high frequency thyroid ultrasound (HFUS) can be used to treat several gland conditions. The recurrent thyroid cyst that was usually treated in the past with surgery, can be treated effectively by a new procedure called percutaneous ethanol injection, or PEI. With ultrasound guided placement of a 25 gauge needle within the cyst, and after evacuation of the cyst fluid, about 50% of the cyst volume is injected back into the cavity, under strict operator visualization of the needle tip. The procedure is 80% successful in reducing the cyst to minute size.
   This modality is suitable for young and pregnant people. Indications for thyroidectomy can be separated into absolute indications or relative indications. These indications aid in deciding which people would benefit most from surgery. The absolute indications are a large goiter (especially when compressing the trachea), suspicious nodules or suspected cancer (to pathologically examine the thyroid), and people with ophthalmopathy and additionally if it is the person's preferred method of treatment or if refusing to undergo radioactive iodine treatment. Pregnancy is advised to be delayed for 6 months after radioactive iodine treatment.
   The sum activity of peripheral deiodinases ("G", also referred to as SPINA-GD) is reduced in nonthyroidal illness with hypodeiodination.
  
  "G" is obtained with
  
  formula_5
  
  or
  
  formula_5
  
  formula_7: Dilution factor for T3 (reciprocal of apparent volume of distribution, 0.026 l)
  
  formula_8: Clearance exponent for T3 (8e-6 sec)
  
  "K": Dissociation constant of type-1-deiodinase (5e-7 mol/l)
  
  "K": Dissociation constant T3-TBG (2e9 l/mol)
  
  Section::::Structure parameters.:TSH index.
  
  Jostel's TSH index (JTI or TSHI) helps to determine thyrotropic function of anterior pituitary on a quantitative level. It is reduced in thyrotropic insufficiency and in certain cases of non-thyroidal illness syndrome.
  
  It is calculated with
  
  formula_9.
   Blood free thyroxine and TSH levels are monitored to help determine whether the dose is adequate. This is done 4–8 weeks after the start of treatment or a change in levothyroxine dose. Once the adequate replacement dose has been established, the tests can be repeated after 6 and then 12 months, unless there is a change in symptoms. Normalization of TSH does not mean that other abnormalities associated with hypothyroidism improve entirely, such as elevated cholesterol levels.
   BULLET::::- 30-85% of papillary carcinoma is multifocal disease. Hemithyroidectomy may leave disease in the other lobe. However, multifocal disease in the remnant lobe may not necessarily become clinically significant or serve as a detriment to patient survival.
  
  BULLET::::- Ease of monitoring with thyroglobulin (sensitivity for picking up recurrence is increased in presence of total thyroidectomy, and ablation of the remnant normal thyroid by low dose radioiodine 131 after following a low iodine diet (LID).
  
  BULLET::::- Ease of detection of metastatic disease by thyroid and neck node ultrasound.
   Fine needle aspiration cytology (FNAC) has a sensitivity and specificity percentages of 81% and 100%, respectively, in the histopathology of malignant cervical lymphadenopathy. PET-CT has proven to be helpful in identifying occult primary carcinomas of the head and neck, especially when applied as a guiding tool prior to panendoscopy, and may induce treatment related clinical decisions in up to 60% of cases.
   Diagnosis is primarily performed via fine needle aspiration of the lesion of the thyroid to distinguish it from other types of thyroid lesions. Microscopic examination will show amyloid and hyperplasia of parafollicular C cells.
  
  Section::::Treatment.
  