Ans. a. Nutmeg liver with dark areas of perivenular dead hepatocytes and gray areas of periportal viable hepatocytes (Ref: Robbins 9/e p864. 8/e p872)This is a classical picture of nutmeg liver seen in chronic passive venous congestion on liver. The dark congested areas consist of necrotic hepatocytes while the surrounding paler and brownish appearing regions are viable hepatocytes."The combination of hypoperfusion and retrograde congestion acts synergistically to cause centriiobular hemorrhagic necrosis. The liver takes on a variegated mottled appearance, reflecting hemorrhage and necrosis in the centriiobular regions. This finding is known as nutmeg liver due to its resemblance to the cut surface of a nutmeg. "-- Robbins 9/e p864Passive Congestion and Centriiobular NecrosisHepatic manifestations of systemic circulatory compromise-passive congestion & centriiobular necrosis can be seen in both left & right-sided heart failureQ.Pathology:Right-sided cardiac decompensation leads to passive congestion of the liver. The liver is slightly enlarged, tense, and cyanotic, with rounded edges. Microscopically there is congestion of centriiobular sinusoids. With time, centriiobular hepatocytes become atrophic, resulting in markedly attenuated liver cell platesQ.Left-sided cardiac failure or shock may lead to hepatic hypoperfusion & hypoxia, causing ischemic coagulative necrosis of hepatocvtes in the central region of the lobule (centrilobular necrosisQ).Combination of hypoperfusion & retrograde congestion acts synergistically to cause centriiobular hemorrhagic necrosis. The liver takes on a variegated mottled appearance, reflecting hemorrhage & necrosis in the centriiobular regions. This finding is known as nutmeg liver due to its resemblance to the cut surface of a nutmegQ.Liver with chronic passive congestion and hemorrhagic necrosisCentral areas are red & slightly depressed compared with the surrounding tan viable parenchyma, forming a "nutmeg liver" patternCentriiobular necrosis with degenerating hepatocytes and hemorrhage