Polycystic Liver Disease (PLD) with possible underlying infection or malignancy: This condition is characterized by the presence of multiple liver cysts and can be associated with systemic symptoms such as fatigue and weight loss, especially if there's an underlying infection or malignancy affecting the liver.

Pyogenic Liver Abscess: Although typically presenting with fever and right upper quadrant pain, a liver abscess could cause night sweats, fatigue, and weight loss, especially if the infection is chronic or partially treated.
Liver Metastases: Metastatic disease to the liver from a primary cancer elsewhere in the body could explain the liver cysts (if they are actually metastatic lesions) and the systemic symptoms of night sweats, fatigue, and weight loss.
Hydatid Disease of the Liver: Caused by the Echinococcus parasite, this condition can lead to the formation of cysts in the liver and may be associated with systemic symptoms if the disease is advanced or if there's a rupture of a cyst.

Hepatocellular Carcinoma (HCC): Although less likely, HCC could present with liver cysts or lesions that mimic cysts, along with systemic symptoms like weight loss, fatigue, and night sweats. Missing this diagnosis could be fatal.
Tuberculosis (TB) Involving the Liver: TB can cause a wide range of symptoms including night sweats, weight loss, and fatigue. Liver involvement could lead to the formation of cystic lesions or abscesses.
Lymphoma Involving the Liver: Both Hodgkin and non-Hodgkin lymphoma can involve the liver and cause systemic symptoms. The presence of liver cysts might be less common but could be part of the disease presentation.

Cystic Echinococcosis (Hydatid Disease) with Rupture: While not the most common presentation, a ruptured hydatid cyst could lead to severe allergic reactions, secondary infections, or dissemination of the disease, explaining the systemic symptoms.
Biliary Cystadenoma or Cystadenocarcinoma: These are rare tumors of the bile duct that can present as cystic lesions in the liver. They might cause obstructive symptoms or systemic symptoms if they become malignant.
Congenital Hepatic Fibrosis: A rare condition that can lead to the formation of cystic lesions in the liver due to fibrosis and ductal plate malformation. Systemic symptoms could occur if there's significant liver dysfunction or associated conditions like Caroli's disease.