Hepatic Steatosis - Histopathology (+ Normal Liver Histology)

Summary

This video explores the intricate structure and function of liver parenchyma, detailing the anatomy of hepatic lobules, including central veins and portal triads. It highlights the three zones of the lobules, emphasizing their varying susceptibility to ischemia and toxic injury. The discussion includes the characteristics of hepatocytes and the role of Kupffer cells. It also addresses fatty liver disease, its causes, and the types of steatosis, emphasizing the condition's reversibility. Additionally, it touches on the importance of histological techniques in accurately visualizing liver pathology.

Takeaways

• 🩺 The liver parenchyma is organized into hexagonal hepatic lobules, with central veins at the center and portal triads at the periphery.
• 🌿 The periportal zone (Zone 1) is well-supplied with oxygen and nutrients, making it less susceptible to ischemia and toxic injury.
• ⚠️ The central lobular area around the central vein is the most susceptible to ischemia and toxic injury.
• 🔍 The portal triad consists of a bile duct lined with cuboidal epithelium, a hepatic artery, and a portal vein.
• 🧬 Normal hepatocytes are polygonal cells with abundant cytoplasm and centrally placed round nuclei, which can vary in size.
• 🌱 Hepatocytes can exhibit clear nuclei due to glycogen content, especially in younger individuals or in conditions like fatty liver disease.
• 🦠 Kupffer cells, which are macrophages, can be found within the liver, some containing pigment in their cytoplasm.
• 💧 Intracytoplasmic clear vacuoles in hepatocytes indicate steatosis or lipid accumulation, which may not be visible in H&E staining.
• 📉 Focal fatty change in the liver is commonly associated with obesity, diabetes, alcohol abuse, and malnutrition.
• 🔄 Steatosis of the liver is reversible, and lifestyle changes can help, often observed in individuals after celebrations.

Q & A

What is the structural shape of the hepatic lobule?

The hepatic lobule is theoretically shaped like a hexagon.

What is found at the center of the hepatic lobules?

The central veins are located at the center of the hepatic lobules.

What are the three zones of the hepatic lobule and their characteristics?

The three zones are: 1) The periportal zone (Zone 1), which is well-supplied with oxygen and nutrients, making it least susceptible to ischemia; 2) The central lobular area, which is most susceptible to ischemia and toxic injury; 3) The mid-zonal area, which serves as an intermediate zone.

What constitutes the portal triad in the portal biliary space?

The portal triad consists of the bile duct lined by cuboidal epithelium, the hepatic artery, and the portal vein.

Describe the characteristics of normal hepatocytes.

Normal hepatocytes are polygonal cells with abundant, slightly granular cytoplasm, centrally placed round nuclei, and often have a prominent nucleolus. Variation in nuclear size is common, especially in older individuals.

What is the significance of clear nuclei in hepatocytes?

Clear nuclei in hepatocytes, often due to glycogen content, are common in younger individuals and may also indicate fatty liver disease or Wilson's disease.

What are Kupffer cells and where are they located?

Kupffer cells are macrophages found in the liver, some of which may contain thyroid pigment in their cytoplasm.

How can lipid accumulation in hepatocytes be detected?

Lipid accumulation can be detected by performing a frozen section and using special stains like oil red, as routine processing may wash away lipids.

What are some causes of focal fatty change in the liver?

Focal fatty change in the liver can be associated with obesity, diabetes, alcohol abuse, dyslipidemia, malnutrition, steroid use, or certain chemotherapeutic agents.

What are the two types of steatosis mentioned in the transcript?

The two types of steatosis are macrovesicular steatosis, where large vesicles distort the nucleus, and microvesicular steatosis, which involves smaller vesicles.