Eosinophilic effusions
Eosinophilic effusions Eosinophilic pleural effusion is an uncommon disorder characterized by a very high number of eosinophils, usually more than 10% of the cells. Some cases occur in the setting of a predisposing cause, but in about one-third of cases the origin remains obscure. Most cases resolve spontaneously. Eosinophilic pericardial and peritoneal effusions are even […]
Rheumatoid pleuritis
Less than 5% of patients with rheumatoid arthritis develop pleural involvement. The effusion can be unilateral or bilateral and a pericardial effusion may also occur in some cases. The cytologic picture is very characteristic. Abundant clumps of granular debris Macrophages The abundant granular material can stain green, pink, red or orange with the Papanicolaou stain, […]
Systemic lupus erythematosus (SLE)
Systemic lupus erithematosus (SLE) About one-third of patients with SLE develop a pleural or pericardial effusion, or less commonly a peritoneal effusion. The characteristic cell is the lupus erythematosus (LE) cell, a neutrophil or macrophage containing an ingested cytoplasmic particle called hematoxylin body. The hematoxylin body can be green, blue or purple with the Papanicolaou […]
Primary effusion lymphoma
Primary effusion lymphoma It is a large B-cell lymphoma which presents as a pleural, pericardial or peritoneal effusion. There is no associated mass lesion or lymphadenopaty. Most cases arise in the setting of HIV infection. The prognosis is poor. Cytologic diagnostic features Dispersed large cells Round or irregular nuclei, prominent nucleoli Abundant basophilic cytoplasm (Romanowsky […]
Reporting terminology
Diagnoses are reported as negative for malignant cells, positive for malignant cells or suspicious for malignancy, followed by a description. A case is called suspicious when the abnormal cells are too poorly preserved or too few to support a definite diagnosis of malignancy. Criteria for the adequacy of effusion specimens have not been established.
Metastatic tumours
Metastatic tumours Carcinoma Malignant melanoma Non-Hodgkin lymphoma Sarcoma Metastatic carcinoma Metastatic carcinomas are by far the most common tumors found in effusions. Adenocarcinomas are more common than squamous cell or undifferentiated carcinomas. Histologic types which can be diagnosed: Adenocarcinoma Small cell carcinoma Squamous cell carcinoma In most cases the cells are morphologically distinct from mesothelial […]
Benign elements
Benign elements Benign effusions contain mesothelial cells, histiocytes and lymphocytes in varying proportions. Because some bleeding can often occur during specimen collection, red and white blood cells are common. Mesothelial cells Macrophages Lymphocytes Neutrophils Eosinophils Plasma cells Mesothelial cells Usually dispersed as isolated cells Occasional sheets or small clusters with windows Round cells Round nucleus, […]
Non-neoplastic conditions
Non-neoplastic conditions In many benign disorders, effusions show a non-specific cytologic picture. However, some conditions are characterized by specific cytologic features which may be helpful in the differential diagnosis. Acute serositis Eosinophilic effusions Tuberculosis pleuritis Rheumatoid pleuritis Systemic lupus erithematosus (SLE) Effusions due to pulmonary infarct Reactive mesothelial cells (often) Mitoses Haemosiderinophages Eosinophils (up to […]
Acute serositis
Acute serositis Acute pleuritis, pericarditis and peritonitis are usually the result of a bacterial infection. Bacterial infection of the pleura occurs in the setting of pneumonia, secondarily involving the overlying pleura and resulting in a pleuric empyema. Acute infection of the peritoneal cavity is often secondary to inflammation of or injury to the bowel, as […]
Tuberculosis pleuritis
Tuberculosis pleuritis 80-100% lymphocytes No or few mesothelial cells Pleural effusions in patients with tuberculous pleuritis have a characteristic, but not specific, cytologic appearance. The fluid is turbid and greenish-yellow. Cytologic preparations are highly cellular and composed almost exclusively of dispersed small lymphocytes, which immunophenotyping shows to be T cells. Mesothelial cells and histiocytes are […]