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Spleen Fine Needle Aspiration Nothing to be afraid of A. A. Pérez Martínez, M. Adán-Martín B. R. Juárez Tosina, C. Y. Herrero Gómez D. A. Enríquez Puga,J. Pinto Varela Objetives • • • To review the basic anatomy and CT imaging findings of spleen abnormalities To review the main indications, contraindications and potential complications of spleen fine-needleaspiration (FNA) guided by CT. To highlight the adecuate interventional procedures to obtain enough cytologic material. Gross Anatomy The spleen is an oblong or ovoid organ in the left upper abdomen. The contour of the superior lateral border of the spleen is convex, conforming to the shape of the adjacent abdominal wall and left hemidiaphragm. The hilum is concave where it conforms to the shape of the adjacent left kidney. The medial surface anterior to the hilum is in contact with the stomach. Microscopic Anatomy White Pulp: lymphoid compartment. Consists of both follicular Bcell-rich areas as well as T-cell-rich periarteriolar lymphoid sheaths. Red Pulp: large volume of erythrocytes. Four vascular structures: slender and nonanastomosing arterial vessels; splenic cords; large, thin-walled venous vessels called sinusoids; pulp veins which drain the sinusoids. CT Anatomy On images performed without intravenous contrast material, the spleen has homogeneous density (55-65 Hounsfield units). Normal size: 12x7x4cm. 150g of weight. CT Anatomy The splenic artery and vein and their branches enter the spleen in the hilum The spleen has smooth margins sharply demarcated from the adjacent fat Imaging findings Technique 5mm slice thickness with 5mm reconstruction interval The use of intravenous contrast material is essential. Normal heterogeneous enhancement during the parenchymal phase of opacification. Imaging findings Infectious diseases Bacterial abscess may be due to metastatic infection, contigous infection, embolic noninfectious events, iatrogenic, immunodeficiency conditions and trauma. Lowattenuation center of fluid or necrotic tissue with minimal peripheral contrast enhancement. The presence of gas inside the collection is diagnostic. Fungal Microabscess: multiple small lesions of low attenuation. Tuberculosis: irregular areas of low density. May produce septic emboli and infaction. Imaging findings Cysts Incidental. Primary (true) and secondary (false) are difficult to differenciate Typically seen as round, well-defined cystic lesions with water attenuation with a thin or imperceptible wall and no rim enhancement. Imaging findings Infarction Key imaging finding: wedgeshaped, peripheral, hypoattenuating lesion. Many appear round or irregular. Also as hypoattenuating lesion with poor defined margins, indistinguishable from other lesions (abscesses, tumors). Imaging findings Splenomegaly There are a lot of causes: congestion (portal hypertension), infiltrative diseases (histiocytosis) hematologic disorders (polycytemia vera), inflamatory diseases (infectious mononucleosis), cysts or tumors (metastases, lymphoma, leukemia). Imaging findings Benign tumors Hemangioma usually an indicental finding. They appear as solid or cystic mass, and may enhance with contrast material in a similar fashion to that of hepatic hemangioma. Hamartoma: incidentally found. Iso- or hypoattenuating mass. Imaging findings Malignant tumors Angiosarcoma: may manifest with well-defined nodules or difusse splenic involvement. CT shows an enlarged spleen with hypoattenuating lesions on nonenhanced scans and contrast enhancement is variable. Lymphoma: most common spleen malignancy. The CT appearances is similar to a variety of splenic pathologies: homogeneus enlargment without a discrete mass, solitary mass, multifocal mass and diffuse infiltration. Imaging findings Malignant tumors Metastatic disease: up to 7% of patients with malignancy. 50% melanoma. CT images show slighty hypoattenuating areas, that may be solid or cystic. The role of Interventional Radiology in Spleen Diagnosis As stated before, many pathologies affecting the spleen have a similar appearance on CT imaging. Characterization of spleen lesions only by imaging techniques may be impossible. Spleen FNA and microbiopsy may help to achieve a final diagnosis. Clinical Indications of FNA Suspected lymphoma Known primary malignancy with suspected metastases Immunosuppressed patients with splenic lesions Incidental splenic lesion with uncertain diagnosis. Contraindications Abnormal coagulation status Infectious mononucleosis Polycythemia vera Megakaryocytic myelosis with thrombocytosis Complications Low rate of complications (0-2% reported in the literature) Potentially: -- Subcapsular hematoma (most common) -- Peritoneal hemorrhage -- Infection -- Pneumothorax -- Pleural effusion -- Colonic, renal or pancreatic injure FNA procedure Prerrequisites: Signed informed consent form Normal platelet count and coagulation screen -- platelet count: 150-450x109/l -- prothrombin time:11.3 -13.3 sec. -- activated partial thromboplastin time: 20-33sec. FNA procedure Unenhanced CT scan is performed Contrast enhanced CT scan is performed if no previous diagnostic study is available. FNA procedure A radiopaque grid is placed on the skin of the patient, to define the entry point The path is chosen trying to cross the lowest volume of normal splenic tissue. FNA procedure The skin is cleaned with a bactericidal agent and infiltrated with a local anesthesic agent (1-2% lidocaine). FNA procedure Fine-needle aspirations are performed with 20gauge or 22-gauge self-aspirating Crown needle. FNA procedure The needle is placed at the periphery of the splenic lesion, and then rapidly and repeatedly advanced and withdrawn 1-2cm. Each biopsy is performed during suspended respiration FNA procedure Biopsy material is sent for histologic examination preserved in a tube containing formalin and for cytologic examination smeared on a slide and immersed in 96% ethyl alcohol. Our Experience 27 Spleen FNA 2002-2009 All were CT guided FNA: 20-g Microbiopsy: 19-g Only FNA: 14 cases FNA and microbiopsy : 13 cases Stains: HE, Giemsa, Papanicolau Aditional techniques: Inmunohistoquímic Molecular techincque 8 patients underwent splenectomy (diagnostic / therapeutic) RESULTS Patients 27 Women 13 Men 14 Complaint Abdominal pain + constitutional syndrome 14 Constitutional syndrome 1 Incidental 12 Imaging findings Splenomegaly + nodule/s 18 Nodules/s 5 Cyst 2 Difuse splenomegaly 1 RESULTS DIAGNOSIS NEOPLASMS NON TUMORAL LESIONS INSUFICIENT Nº Linfoid 12 Non linfoids 4 Cysts 2 Granulomes 2 Negative 6 1 RESULTS The spleen-FNA combined with microbiopsy was diagnostic in 96% of the cases. In 1 case (3,7%) there wasn´t enough cytologic material for diagnosis. COMPLICATIONS We only had 1 case with complications (3,7%). The patient developed a splenic abscess, which was succesfully treated with percutaneous drainage and antibiotherapy Our Cases Patient admitted to complete splenomegaly study. A bone-marrow biopsy was performed. It was normocellular, without evidence of lymphoproliferative process. Spleen FNA and microbiopsy were performed. FNA Microbiopsy CD20 Our Cases Abdominal CT: homogeneous splenomegaly. FNA and microbiopsy were performed. FNA: monomorphic proliferation of small lymphoid cells. Microbiopsy: diffuse proliferation of small lymphoid cells : cd20+, bcl2+ Diagnosis: SMALL CELLS B LYMPHOMA. Our Cases Patient admitted due to anemia and possible GI bleeding. CT findings: hepatic hypodense nodules, with multiple lymphadenopaties in hepatic hilium compressing the vena porta. Retroperitoneal mass involving pancreatic body and tail. Splenomegaly with multiple hypodense nodules. Lymphoma was the first diagnostic possibility. CT guided FNA and Microbiopsy were performed. ACT DESM Microbipsy ACT FNA: fibrosis, isolated grups of atipyc cells with fusiform and hypercromatic nuclei: actine and desmine +. Microbiopsy: elongated cells with fusiform, pleomorphic and hypercormatic nuclei, and atipycal mitosis . Actine, desmine and vimentin +. s100, cd34, ckit,alc, cd68-. Diagnosis: Leiomyosarcoma Summary Characterization of spleen lesions only by imaging techniques may be impossible. The FNA is a usefull and safe procedure to diagnose infections and tumorals diseases of the spleen.