Pathology
Characteristic feature is the identification of intimately related syncytiotrophoblasts and cytotrophoblasts without formation of definite placental type villi. Since choriocarcinomas include syncytiotrophoblasts (beta-HCG producing cells), they cause elevated blood levels of beta-human chorionic gonadotropin. Syncytiotrophoblasts are large multi-nucleated cells with eosinophilic cytoplasm. They often surround the cytotrophoblasts, reminiscent of their normal anatomical relationship in chorionic villi. Cytotrophoblasts are polyhedral, mononuclear cells with hyperchromatic nuclei and a clear or pale cytoplasm. Extensive hemorrhage is a common finding. Treatment
Since gestational choriocarcinoma (which arises from a hydatidiform mole) contains paternal DNA (and thus paternal antigens), it is exquisitely sensitive to chemotherapy. The cure rates, even for metastatic gestational choriocarcinoma, more than 90% when using chemotherapy for invasive mole and choriocarcinoma.As of 2019, treatment with either single-agent methotrexate or actinomycin-D is recommended for low-risk disease, while intense combination regimens including EMACO (etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine (Oncovin) are recommended for intermediate or high-risk disease.Hysterectomy (surgical removal of the uterus) can also be offered to patients >40 years of age or those for whom sterilisation is not an obstacle. It may be required for those with severe infection and uncontrolled bleeding. Choriocarcinoma arising in the testicle is rare, malignant and highly resistant to chemotherapy. The same is true of choriocarcinoma arising in the ovary. Testicular choriocarcinoma has the worst prognosis of all germ-cell cancers. References
External links

00976 at CHORUS
Causes
Conditions contributing to lung abscessAspiration of oropharyngeal or gastric secretion
Septic emboli
Necrotizing pneumonia
Vasculitis: Granulomatosis with polyangiitis
Necrotizing tumors: 8% to 18% are due to neoplasms across all age groups, higher in older people; primary squamous carcinoma of the lung is the most common.OrganismsIn the post-antibiotic era pattern of frequency is changing. In older studies anaerobes were found in up to 90% cases but they are much less frequent now. Anaerobic bacteria: Actinomyces, Peptostreptococcus, Bacteroides, Fusobacterium species,
Microaerophilic streptococcus : Streptococcus milleri
Aerobic bacteria: Staphylococcus, Klebsiella, Haemophilus, Pseudomonas, Nocardia, Escherichia coli, Streptococcus, Mycobacterium

Fungi: Candida, Aspergillus
Parasites: Entamoeba histolytica

Diagnosis
Imaging studies
Lung abscesses are often on one side and single involving posterior segments of the upper lobes and the apical segments of the lower lobes as these areas are gravity dependent when lying down. Presence of air-fluid levels implies rupture into the bronchial tree or rarely growth of gas forming organism. Laboratory studies
Raised inflammatory markers (high ESR, CRP) are common but nonspecific. Examination of the coughed up mucus is important in any lung infection and often reveals mixed bacterial flora. Transtracheal or transbronchial (via bronchoscopy) aspirates can also be cultured. Fiber optic bronchoscopy is often performed to exclude obstructive lesion; it also helps in bronchial drainage of pus. Management
Broad spectrum antibiotic to cover mixed flora is the mainstay of treatment. Pulmonary physiotherapy and postural drainage are also important. Surgical procedures are required in selective patients for drainage or pulmonary resection. The treatment is divided according to the type of abscess, acute or chronic.