Cytopathology

Overview of Cytopathology

• Cytopathology focuses on diagnosing diseases by examining the microscopic appearance of individual or grouped cells.
• Unlike histology, which examines solid tissues, cytopathology analyzes 'loose' cells.

Sample Collection for Cytopathology

• Cells can be aspirated, brushed, or collected from various body sites for examination.
• Diagnostic samples can be obtained from tissue surfaces, body fluids, lumps, or lesions.

Screening and Diagnostic Work

• Cytopathology includes both screening and diagnostic work to detect abnormalities.
• A successful screening program needs to identify diseases early, provide effective treatment, and be non-invasive.

NHS Cervical Screening Program

• The NHS runs three main screening programs: bowel, breast, and cervical screening.
• Cervical screening involves a call at age 25 with repeated screenings every three years until age 50 and every five years until age 65.

Cervical Anatomy and Cell Types

• The cervix, located at the top of the vagina and at the entry to the uterus, has both columnar (endocervix) and squamous (ectocervix) epithelial linings.
• The transformation zone, where the endocervix and ectocervix meet, is highly susceptible to precancerous changes.

Cytology vs. Histology

• Cytology uses the cervical smear test to collect and stain loose cells, primarily screening for abnormalities.
• Histology involves cone biopsy to obtain tissue samples for further examination.

HPV Testing and Its Importance

• The primary method in cytology includes PCR testing for HPV, only examining cells if HPV is positive.
• The HPV vaccine significantly reduces the incidence of cervical cancer and other HPV-related cancers.

The Impact of the Pap Test

• The Pap test is renowned as the most effective cancer screening program, reducing cervical cancer death rates by over 70%.
• Prior to its introduction, cervical cancer was the leading cause of cancer death among women but fell to the fifteenth position afterward.

Understanding Pre-Cancerous Changes

• Pre-cancerous changes, known as dyskaryosis, manifest through nuclear enlargement, irregular shape, hyperchromasia, and multinucleation.
• Dyskaryosis grading is based on the nucleo-cytoplasmic ratio (NCR), classifying it into mild, moderate, or severe.

Treatment Methods for Cervical Conditions

• Colposcopy is typically used to treat cervical intraepithelial neoplasia (CIN), allowing for biopsies to determine CIN grade.
• Large loop excision of the transformation zone (LLETZ) is often performed to remove CIN lesions; hysterectomy may be necessary in severe cases.

HPV and Its Mechanisms

• HPV is a double-stranded DNA virus; its oncogenes E6 and E7 contribute to cancer by targeting tumor suppressor genes like p53 and retinoblastoma protein.
• The expression of E6/E7 mRNA is a key indicator for detecting high-risk HPV infections linked to cervical cancer.

Diagnostic Techniques in Cytopathology

• Diagnostic techniques include scraping, centrifugation, brushing, washing, and aspirating cells from various sites.
• Analyzing samples using H&E staining helps visualize cell morphology, highlighting differences indicative of pre-cancerous or cancerous changes.### Cytopathological Evaluation
• Cells can be obtained from lumps or lesions using a blood-taking needle for cytopathological evaluation.
• Common sample sites include the bladder, pancreas, bile duct, breast, thyroid, salivary glands, semen, lymph nodes, and any accumulating fluid.

Fluid Samples and Preparation

• Fluids for cytological examination include urine, cerebrospinal fluid (CSF), and various effusions.
• Fluid samples are centrifuged to separate plasma and cellular components; the Buffy coat contains white blood and tumor cells, which are then prepared on microscope slides for staining.

Staining Methods

• Papanicolaou stain (for 'wet-fixed' specimens): Comprises haematoxylin, EA50, OG6, provides excellent nuclear detail.
• Romanowsky stain (for 'air-dried' specimens): Includes May-Grunwald and Giemsa stains, effective for highlighting cytoplasmic detail.

Cerebrospinal Fluid (CSF)

• CSF is a clear fluid surrounding the brain and spinal cord, crucial for cushioning, chemical stability, and nutrient exchange.
• Cancer spread to the central nervous system may cause neurological symptoms and poor prognosis.

Urine Cytology

• Primarily screens for urinary tract infections, cancer, or precancerous conditions.
• Typically performed in patients with hematuria; may accompany ultrasound and cystoscopy.
• 10-25% of hematuria patients may be diagnosed with bladder cancer, especially in high-risk occupations.

Bladder Cancer Overview

• Urothelial carcinoma is the most common bladder cancer, making up 90% of cases in the UK; it arises from transitional cells.
• Squamous cell carcinoma (5% of cases) is more prevalent in Africa and Asia and linked to bilharzia infection.
• Adenocarcinoma is a rare type (1-2% of cases) that develops from glandular cells.

Cytology Techniques in Bronchoscopy

• Bronchoscopes utilize fiber optics and instruments for sampling; bronchoalveolar lavage (BAL) washes airways for cytology or microbiology.
• BAL is especially useful for diagnosing opportunistic infections in immunocompromised patients.

Lung Cancer Types

• Squamous cell carcinoma: Second most common lung cancer, linked to smoking, often presents with necrosis.
• Adenocarcinoma: Most common lung cancer, occurs in smokers and non-smokers, often diagnosed at advanced stages.
• Small cell carcinoma: Highly malignant, early metastasis, responds dramatically to treatment.

Thyroid Gland and Pathology

• The thyroid gland produces hormones (T3 and T4) crucial for metabolic functions; nodules are common, requiring pathological diagnosis.
• Fine needle aspiration (FNA) is employed to assess nodule malignancy; <10% of suspicious nodules are malignant.

Thyroid Carcinomas

• Papillary thyroid carcinoma: Most frequent, often slow-growing, treated with total thyroidectomy.
• Medullary carcinoma: Arises from parafollicular cells, includes hereditary forms and may present with diarrhea.

Breast Cancer Statistics

• Leading cancer in women, comprising 25% of cases, peak incidence age is 55-69, with a 5-year survival rate of 80-90%.
• Signs include lumps, skin changes, and discharge; about 5-10% of cases are genetically predisposed.

Breast Carcinoma Types

• Ductal carcinoma: Makes up 80% of cases, can be invasive or in situ (DCIS), with significant hormone receptor status implications.
• Lobular carcinoma: Accounts for 10-15% of breast cancers, with distinct histological features.

Breast Aspiration Findings

• Normal aspirates yield benign cells; fibroadenomas present cellular samples with benign ductal cells.
• The absence of myoepithelial cells and crowded epithelial sheets may indicate malignancy.### Lobular Carcinoma
• Characterized by linear cords or clusters of cells with absent myoepithelial cells.
• Difficult to detect due to lack of lump formation, low cellularity, and limited atypia.

Cytology

• Advantages:
  • Quick results (minutes).
  • Cost-effective and less invasive, allowing faster patient recovery.
  • Can provide same-day diagnosis for benign lesions.
• Disadvantages:
  • Requires specialized expertise.
  • May lack sensitivity and specificity.

Histology

• Advantages:
  • Considered gold standard for diagnosis.
  • Easier to perform ancillary tests.
• Disadvantages:
  • Results may not be available on the same day.
  • Generally more expensive and invasive.

Andrology in Hospitals

• Crucial for fertility clinics, offering insights on male fertility.
• Typically found within Gynaecology or Urology departments.
• Andrology labs provide outpatient services, including bookings, patient interviews, and result reporting.

Hormonal Regulation of Sperm Production

• Sperm production is driven by hormones from the hypothalamus and anterior pituitary gland.
• The hypothalamus secretes gonadotropin-releasing hormone (GnRH).
• Anterior pituitary gland releases follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in response to GnRH.
• FSH promotes spermatogenesis; LH stimulates testosterone production by Leydig cells.

Spermatogenesis and Testes Structure

• Occurs within the seminiferous tubules of the testes.
• Leydig cells produce testosterone, essential for male reproductive function.
• Each seminiferous tubule measures approximately 700 feet in length.
• Up to 120 million sperm can be produced daily; spermatogenesis takes about 64 days.
• Stem cells lining seminiferous tubules initiate sperm production.

Germ Cell Arrangement and Quality Control

• Germ cells are arranged in a systematic manner in seminiferous tubules.
• Quality control mechanisms ensure biological and genetic integrity of sperm.

Subfertility and Infertility Statistics

• Defined as the inability to conceive after 12 months of trying.
• Approximately 1 in 7 couples in the UK experience difficulties conceiving.
• Infertility causes: unexplained factors (25%), ovulatory disorders (25%), tubal damage (20%), male factor (30%), and uterine or peritoneal disorders (10%).

Referral Process for Fertility Evaluation

• Referrals typically come from GPs, Gynaecology, and Urology departments for patients trying to conceive for a year without success.
• Patients undergoing radiation or chemotherapy may also be referred for evaluation.

Spermatozoon Structure

• Comprises three sections: head, neck, and tail.
• The head contains a nucleus with compacted DNA and an acrosome for fertilization.
• The neck connects the head and tail, comprising the connecting piece and proximal centriole.
• The tail, powered by the midpiece, consists of the axial filament.

Sperm Morphology and Function

• Sperm morphology refers to the size and shape of sperm, important for fertility assessments.
• Normal morphology is deemed sufficient when 4% or more sperm are normal.
• Abnormal morphology includes misshapen heads, coiled tails, and other defects which can affect fertility.

Semen Appearance and Consistency

• Normal semen is gray, liquefies within 30 minutes, and has a distinct odor.
• Abnormal semen may appear brown or red, fail to liquefy after 60 minutes, or contain mucus.
• Consistency is classified as normal or viscous based on threading with a sample.

Semen pH and Volume Measurement

• pH measured using indicator papers; a pH lower than 7.2 may indicate a blockage, while higher may suggest infection.
• Semen volume, with a lower reference limit of 1.5 ml, is measured by weight.

Sperm Motility and Concentration

• Number of progressive sperm is a key predictor of fertilization and pregnancy success.
• Sperm motility categorized as progressive, non-progressive, or immotile.
• Low motility is classified as progressive motility under 32% or total under 42%.
• Sperm concentration calculated after appropriate dilution and assessed with a haemocytometer.

Assisted Reproductive Technologies

• Options for patients with abnormal sperm characteristics include:
  • Intrauterine insemination (IUI): 10-12% success rate per month.
  • In-vitro fertilization (IVF): 25-50% success rate per round.
  • Intra cytoplasmic sperm injection (ICSI): Single sperm injected into an egg with similar success rates as IVF.
• Donor sperm may be used when a patient's semen is not viable for these techniques.

Explore the fundamentals of cytopathology, including its definition and the types of samples it examines. This quiz covers cell collection methods and the scope of work involved in cytopathological examinations, providing a comprehensive understanding of this essential field in diagnostics.