Sono 131: Spleen sonographic patterns

• The spleen is studied in Spokane Community College Sono 131.
• The material aims to enable one to describe normal sonographic patterns of the spleen.
• It also provides understanding of sonographic findings for differential diagnosis of splenic pathologies.

Normal Spleen

• The spleen is variable in size and shape.
• It possesses a protective capsule and a bare area.
• Measurements: its length is 8-13 cm, width is 7 cm and thickness is 3-4 cm.
• Volume: Normal range is 107-315 cm3.
• The formula to calculate volume is 0.524 X width X thickness X (ML +CCL)/2.

Splenic Physiology

• The functions include:
• Filter
• Reservoir
• Destruction of red blood cells
• Formation of bile pigments
• Destruction of microorganisms
• Provides Immunity
• Production of lymphocytes
• Production of plasma cells erythropoiesis in the fetus
• Additional information is available at https://youtu.be/Ar6k8-hLxJ4

Role of Ultrasound

• Ultrasound helps assess the size, shape, texture and vascularity of the spleen.
• Indications include trauma, liver disease, and malignancy.
• More information is available at https://www.youtube.com/watch?v=cOzcSyXgedc (spleen ultrasound tutorial) and https://www.youtube.com/watch?v=1yMzX19809w&list=PLcvf7v2FbcnDEPM_HDapPIXN7nbmTipKa (7 spleen pathology videos)

Normal Sonographic Findings

• A fine uniform homogeneous mid to low level echo pattern is normal.
• The texture is more echogenic than the liver.
• An increase in spleen size equals an increase in echogenicity.

Congenital Disorders

• Congenital disorders include Asplenia Syndrome and Polysplenia.

Variants of normal

• Variants of normal include wondering spleen and accessory spleens (Splenule).
• Wandering spleen (Pelvic spleen, ectopic, ptotic, or aberrant) is a rare medical disease caused by the loss or weakening of the ligaments that normally hold the spleen stationary.
• This makes it susceptible to torsion around the vascular pedicle.

Splenomegaly

• Splenomegaly is categorized as congestive, hematologic, infiltrative, metabolic, chronic inflammatory, hematopoietic malignancies, and trauma.
• Congestive: Can be caused by portal hypertension.
• Hematologic: Can be caused by Thalassemia, Hereditary spherocytosis, autoimmune hemolytic anemia, sickle-cell disease.
• Infiltrative: Can be related to Leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma.
• Metabolic: Related to Gaucher's disease, Niemann-Pick disease.
• Chronic inflammatory: Related to Sarcoid, tuberculosis, malaria.
• Hematopoietic malignancies: Acute lymphocytic leukemia, chronic myelogenous leukemia, chronic lymphocytic leukemia, agnogenic myloid metaplasia.
• Trauma: Can be parenchymal hematoma, subcapsular hematoma.

Splenomegaly

• Clinical presentation may include LUQ fullness or pain, jaundice and lymphadenopathy.
• Clinical presentations can also include fever, hemorrhage, and compression of the left kidney, pancreas, stomach, and intestines.
• Etiology related to systemic inflammation and to blood or metabolic disorders.
• Sonographic Findings: Length > 13 cm, Volume >300ccs.
• In addition, it may displace the stomach or fill the abdominal cavity.

Splenomegaly (Congestive)

• Congestive includes heart failure, portal hypertension, cirrhosis, cystic fibrosis and portal or splenic vein thrombosis.
• Acute splenic sequestration is also included in sickle cell disease –.

Hematologic Splenomegaly

• Hematologic causes can include Thalassemia and Hereditary spherocytosis.
• Other hematologic issues are autoimmune hemolytic anemia and sickle-cell disease.

Splenomegaly (Infiltrative)

• This may be caused by Leukemia, Hodgkin's lymphoma, and non-Hodgkin's lymphoma.

Storage Diseases of the Spleen include:

• Amyloidosis
• Gaucher disease
• Niemann-pick disease
• Diabetes mellitus
• Histiocytosis
• Hemochromatosis

Splenic Storage Disease

• Amyloidosis occurs due to abnormal deposition of a particular protein (amyloid), in various tissues of the body.
• Localized amyloidosis means its deposited in a localized area and may not be harmful or only affect a single tissue of the body.
• Systemic amyloidosis affects tissues throughout the body, causing serious changes in virtually any organ of the body.
• Sonographic appearance: Normal size (nodular) or enlarged (diffuse).

Splenic Storage Disease

• Gaucher's disease: 50% of patients are less than 8 years of age.
• Other symptoms are bone pain, changes in skin pigmentation and splenomegaly.
• In Gaucher's disease the patient will have diffuse inhomogeneity and multiple splenic nodules.
• Niemann-Pick disease: a rapidly fatal disease.
• It affects female infants causing hepatomegaly, digestive disturbances and lymphadenopathy.

Splenic Storage Disease – Histiocytosis

• It presents as diffuse sinusoidal infiltration of red pulp by neoplastic histiocytes with extension into cords.
• Hemochromatosis is a specific genetic problem that causes more iron to be absorbed by the body than normal.

Splenomegaly, Systemic Infection & Inflammation

• Mononucleosis is a viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck.
• Tuberculosis occurs through Mycobacterium tuberculosis (mtb), one of the world's most prevalent and deadly infectious diseases.
• Histoplasmosis is a fungal infection with > 6 calcifications. Larger calcifications are typical.
• Schistosomiasis is a parasitic disease from contaminated water.
• It causes severe form of disease and develops into periportal fibrosis and portal hypertension in nearly 10% of infected individuals.
• Sarcoidosis is an inflammatory disease that produces lumps of cells (granulomas) within various organs and tissues throughout the body.
• Granulomas consist of highly differentiated mononuclear phagocytes and lymphocytes.
• People with HIV/AIDs can have Multi-organ involvement or Focal lesions.
• Focal lesions can be candida and Pneumocystis carinii pneumonia.
• Lesions can also be caused by mycobacterium and Disseminated pneumocystis, as well as Lymphoma.

Splenomegaly - Systemic Infection – Candidiasis

• Candidal and other fungal splenic abscesses consist of pus, necrotic tissue, and fungus surrounded by layers of histiocytes, chronic inflammatory cells, and fibrosis.
• A Wheel within a wheel appearance may be present.

Splenic Focal Disease Includes:

• Splenic abscess, Splenic infection, and Acquired immunodeficiency syndrome.
• It also includes Splenic trauma, Splenic cysts and Benign primary neoplasms.
• Benign neoplasms: Hamartoma, cavernous hemangioma, and Cystic lymphangioma
• Malignant primary neoplasms: Hemangiosarcoma and Lymphoma.
• Another disease found in these studies is metastases.

Splenic Cysts include:

• True cysts, Post-traumatic, and cysts caused by infections issues cysts.
• They can also be Neoplastic or Parasitic such as echinococcal.
• Focal Infections & Inflammations can cause: Splenic Abscess.
• Focal Lesions can cause: Splenic Artery Occlusion or be are caused by an Embolic Source, like the heart and lead to Infarction

Splenic Hemtoma

• Forms due to Parenchymal or Subscapular hematoma

Primary Neoplasm – Benign

• Hamartoma is a vascular space occupying lesion lymphoid tissue.
• Hemangioma is a collection of vessels.

Neoplasia – Malignant

• Malignant conditions include Leukemia, Lymphoma and Hemangiosarcoma.
• Metastasis can also be the cause.
• Lymphoma arises from lymph nodes, usually, and be a primary spleen condition. Lymphoma also has Hodgkin's and non-Hodgkin's types which show : Normal, Splenomegaly, and Multiple hypoechoic lesions
• Angiosarcoma is rare, primary, originates from vessel lining and as a result has a poor prognosis.
• Angiosarcoma symptoms include Splenomegaly and Mixed echogenicity as seen through ultrasound or US.
• In cases that are metastasis Us Varies, is rare and commonly results from melanoma and is usually primary.

Some Common Pathologies

• Splenomegaly, Splenic infarction, and Varices, which is also called portal hypertension.
• Other common pathologies are Hemangioma, Metastases, Infection- multiple echogenic foci, Lymphoma.
• Additional pathologies are Cysts, Hematomas, and Abscess.