Spleen Flashcards
What system does the spleen belong to?
Reticuloendothelial system
*the spleen is the largest of lymphoid tissue
Where is the spleen located?
Intraperitoneal
LUQ
Between stomach and diaphragm
Histology of the normal spleen
Enclosed by a fibroelastic capsule
Has trabeculae which divide the spleen into compartments filled with
White and red pulp
What are the measurements of the spleen?
12 cm long
8 cm trv
4 cm AP
What is a useful landmark in identifying the spleen and splenic hilum?
Splenic vein
Which ligament attaches the spleen to the dorsal body wall?
Lienorenal ligament
Which ligament attaches spleen to the stomach?
Gastroluenal ligament
Which ligament supports the spleen inferiorly?
Phreniccocolic ligament
What are the functions of the spleen?
Production of lymphocytes RBC production Erythrocyte destruction Hemoglobin breakdown Bile pigment formation Filtration and trapping of foreign particles Bacteria and virus destruction Storage of iron
What is Aplasia?
Absent spleen
What is splenoptosis?
Downward displacement of the spleen
What are other names for supernumerary spleen?
Accessory spleen
Splenunculus
Polysplenia
What is posttraumatic splenosis?
Following splenic rupture, splenic cells may implant throughout the peritoneal cavity and increase in size, resulting in ectopic spleens
What causes splenomegaly?
Increased work load Portal HTN Budd Chiari syndrome Cirrhosis Hepatitis CHF Cystic Fibrosis
What lab tests are used to evaluate spleen?
Bone marrow test for cancer
Blood protein can r/o multiple myeloma to malaria
Uric acid and ALP to determine presence of leukemia or lymphomas
LFT
What are the dilated sinusoids in an enlarged spleen called?
Reflective channels
What causes a spleen to rupture?
Blunt trauma Crushing injury Spontaneous rupture Infectious mononucleosis Malaria Typhoid fever
Clinical findings of a ruptured spleen
Abdominal pain Rigid abdomen No bowel movement Slow leak may be asymptomatic yet cause hypovolemic shock Left pleural effusion
Lab findings of splenic rupture
Decreased hematocrit
Low HTC
What kind of splenic cysts are there?
Blood Parasite cyst (Hydatid) Congenital cyst: epidermoid Simple cysts: Polycystic disease Pseudocyst: acute pancreatitis Because of high vascularity, pseudocyst may erode the vessels, causing Pseudoaneurysm and bleeding into pseudocyst
Etiology of splenic infarct
Bacterial endocarditis Sickle cell anemia Malignant METS Hypotension Occluded vascular supply
Sonographic appearance of splenic infarct
Atypical
Echogenicity related to age of infarct
Hypoechoic in early stages
Hyperechoic as time progresses
Splenic abscess etiology
Heterogenously disseminated infections 80% Bacterial endocarditis Diverticulitis Osteomyelitis Pelvic infections Trauma Surgery Altered immune system
Clinical/labs of splenic abscess
Pain Fever Leukocytosis Bacteremia and septicemia Blood culture is necessary
Sonographic appearance of splenic abscess
Irregular borders Septa Internal echoes Thick wall Pleural effusion Reverberation artifact due to gas
What is Granulomatous Inflammatory Calcifications?
Focal lesions resulting from previous infections
Etiology of Granulomatous Inflammatory Calcifications
Tuberculosis Histoplasmosis Sarcoidosis Splenic artery Calcifications Reactive hyperplasia Secondary to previous infections Sickle cell disease
Which the most common benign splenic tumor?
Hemangioma
Benign splenic Tumors
Hemangioma Fibroma Lymphangioma Chondroma Plamocytoma Sarcoma
Which is the most common tumor METS to the spleen?
Malignant melanoma
Sonographic findings of splenic mets
Discrete solid mass usually hypoechoic but may have mixed echogenicity
May be multiple
May be complex due to cystic necrosis
