12.1 What do you understand by the term “head and neck” cytology?
This broadly refers to assessment of any masses arising in the head and neck region. These masses include assessment of salivary and thyroid glands, and lymph nodes.
12.2 What is the primary purpose of rapid on-site assessment of FNA smears by biomedical scientists?
The primary purpose of rapid on-site assessment of FNA smears is to permit the immediate recognition of inadequate aspirates, thereby minimising unsatisfactory samples and reducing patient recalls.
12.3 Explain the principle and purpose of ‘non-aspiration’ needle cytology.
With ‘non-aspiration’ needle cytology, cellular material collects in the bore of the needle through the cutting and scraping action of the needle tip rather than by suction.
12.4 Which is the largest salivary gland?
12.5 What can you see in an aspirate of a normal salivary gland?
Acinar and ductal cells are aspirated in FNA of “normal gland”
12.6 What is the function of the parathyroids?
Control of calcium levels.The four parathyroid glands make parathyroid hormone (PTH) in response to the level of calcium in the blood. When the calcium in our blood goes too low, the parathyroid glands make more PTH. ... Increased PTH causes the bones to release their calcium into the blood.
12.7 For the initial investigation of salivary gland enlargements, why do many clinicians prefer FNA to incisional biopsy?
FNA is minimally invasive in an area which may present problems for the incisional biopsy (e.g. proximity of facial nerve). The need for surgery is removed if it can be shown that a lesion is non-neoplastic or if it confirms metastatic or recurrent tumour (in the latter two instances chemo- or radio-therapy being the treatment of choice).
12.8 Which is the most common benign salivary gland tumour?
12.9 Provide a justification for the claim that the cytological examination of cyst contents is a form of exfoliative rather than FNA cytology.
The cellular contents of cysts generally accumulate via exfoliation from the cyst wall. While needle aspiration is the most common procedure for collecting such material, the method does not involve any of the needle cutting action that is normally employed during FNA.
12.10 Can you suggest three potential diagnoses for a lymphocyte-rich salivary gland aspirate?
The differential diagnosis for a lymphocyte-rich salivary gland aspirate might include any of the following: a) lymphoma; b) Warthin’s tumour; c) intraglandular lymph nodes (i.e. lymph nodes that are found inside salivary glands); d) autoimmune sialadenitis; e) acinic cell carcinoma.
12.11 Can you suggest two potential diagnoses for an oncocyte-rich salivary gland aspirate?
The differential diagnosis for an oncocyte-rich salivary gland aspirate might include: a) oncocytoma; b) Warthin’s tumour; c) acinic cell carcinoma.
12.12 What is the main purpose of thyroid cytology?
Fewer than 10% of thyroid nodules are malignant and many do not require immediate surgical intervention. The main purpose of thyroid cytology is to help the clinician decide which patients might benefit from surgery.
12.13 What is the main reason for an unsatisfactory FNA of the thyroid?
Thyroid is a highly vascular tissue and readily bleeds during FNA. A certain amount of blood in a cytology preparation can be tolerated but when it is excessive it can cause extreme dilution of the cellular material, thereby increasing the risk of sampling error and false negative reporting.
12.14 Describe the most important cytological feature distinguishing Hashimoto’s thyroiditis from lymphoma.
Apart from the abundance of lymphocytes, which would be expected in both Hashimoto’s thyroiditis and lymphoma, a thyroid aspirate from a patient with Hashimoto’s disease would normally also contain Hurthle cells.
12.15 The terms “hot” and “cold” are sometimes used by clinicians to describe thyroid nodules. What do these terms mean and how might they help in the cytological interpretation of thyroid FNA samples?
A “cold” nodule is one which takes up little radioactive iodine when it is given to the patient. It indicates normal thyroid activity or an underactive thyroid. Normal thyroid tissue is usually “warm”. Many thyroid cancers are “hot”, i.e. they take up a lot of iodine and appear dark on an x-ray scan. The uptake of radioactive iodine by the thyroid gland is only one indicator of disease and the cytologist must be careful not to rely too heavily on this single piece of clinical information in reaching a diagnosis.
12.16 What is the meaning of the term “lymphadenopathy”?
Lymphadenopathy is an increase in the number, size or consistency of lymph nodes.
12.17 What is the primary purpose of lymph node FNA?
Cytological examination of a lymph node can help determine whether lymphadenopathy is due to reactive hyperplasia, metastatic malignancy or malignant lymphoma, which can assist the clinician to decide whether surgical excision for histological examination is required. Cytology has little role to play in lymphoma classification.
12.18 Explain the clinical importance of finding epithelial cells in a FNA aspirate of a lymph node.
As long as the cytologist can confidently exclude sample contamination, the finding of epithelial cells in a FNA aspirate of a lymph node is diagnostic of metastatic carcinoma.
12.19 Distinguish between the terms lymphoma and leukaemia.
Lymphoma and leukaemia are both white blood cell neoplasms. The difference between them lies in their tissue of origin. Leukaemias originate in bone marrow while lymphomas are derived from lymphoid tissue. Immunophenotyping, cytogenetic or molecular studies are often necessary for making a definitive diagnosis.