Spleen & Pancreas Flashcards
Normal appearances of Spleen
Size: should not be >12-13cm
Shape: ovoid shape that looks like a half moon
- Convex - superior surface
- Concave - inferior surface
- well defined hilum- splenic Vein & Art* visible
Contour: smooth
Echotexture: very smooth & homogeneous
Echogenicity: mid to low level echoes (should be hyperechoic to liver, sometimes isoechoic, but will be hypoechoic to the pancreas & renal sinus
Spleen: normal variants & anomalies
Accessory spleen or Splenunculus:
- found in nearly 1/3 of pop*
- <1 cm diameter or splenic tissue separate from spleen
- commonly seen at hilum w normal splenic appearance
- can be mistaken for lymph node, pancreatic tumour, renal tumour, or adrenal gland mass
Asplenia: absence of spleen
Polysplenia: 2 or more spleens w multiple congenital abnormalities in the abdo & chest
Ectopic accessory spleen:
- small rounded masses of splenic tissue found in various locations other than the LUQ (eg; pancreas or scrotum)
Wandering/mobile spleen:
- due to lax ligaments, spleen can undergo torsion &/or lie in unusual locations
Spleen: indications
- routine abdo US
- detection/confirmation of splenomegaly
- portal hypertension invest* inc a spleen assess*
- masses (1* splenic masses are rare)
- trauma (rupture &/or haemorrhage)
- bacterial endocarditis: abscess, infarction (rare)
Spleen S&S
- palpable enlarged spleen in LUQ
- pain & tenderness LUQ over spleen
- haemolytic abnormalities (blood tests showing inc/dec WBC or RBC counts)
- infection: pain, fever, malaise, nausea, vomiting & leukocytosis (eg; abscess)
- causes of splenomegaly (most common finding in spleen but non-specific)
- infectious Dx: abscesses, TB, mononucleosis, AIDS & malaria
- blood Dx: sickle cell anaemia, polycythemia, or thalassaemia
Infiltrative/Neoplastic Dx: lymphoma & leukaemia
Acute trauma
Splenic cysts
- not commonly seen
- classified as true cysts (rare) or pseudocysts
True cysts:
- epithelial cell lining
- can be further divided into parasitic (hydatid) & non-parasitic
Pseudocysts:
- from past trauma, infarction, or infection
Splenic haemangioma
- most common benign neoplasm of the spleen
- consists of vascular channels
- mostly singular but can have multiple
US:
- well-defined echogenic lesion
Splenic calcifications
- can range from small calcifications to large solitary lesions
Splenic granulomatous Dx:
- multiple small clarified granulomas
- infective (eg; splenic TB)
- non-infective (eg; splenic sarcoidosis)
- large calcifications uncommon - may be caused by hydatid cysts, old infarcts, healed abscesses
Splenic trauma
- among the most common trauma-related injuries
- classified as either penetrating or blunt trauma
- severity can be objectively classified by a grading system
Splenic Injury Scale
Grade I:
- haematoma - subcapsular, <10% surface area
- lac - capsular tear, <1cm parenchymal depth
Grade II:
- haemat* - subcapsular, 10-50% surface area
- intraparenchymal, <5cm diameter
- lac - 1-3cm parenchymal depth (does Not involve trabecular vessel)
Grade III:
- haemat* - subcapsular, >50% surface area or expanding; ruptured subcapsular or parenchymal haematoma
- lac - >3cm parenchymal depth or involve trabecular vessels
Grade IV:
- lac - involving segmental or hilar vessels & producing major devascularisation (>25% of spleen)
Grade V:
- lac - completely shattered spleen
- vascular - hilar vascular inj* that devascularises the spleen
*Advance 1 grade for multiple injuries up to Grade III
Splenic rupture
- AKA splenic lac
- most commonly caused by blunt trauma to abdo (MVA, sports, assault)
S&S
- usually accompanied by other signs of injury form blunt trauma (#ribs, #pelvis, bruising)
- LUQ pain but can be referred to L chest wall/shoulder (Kehr’s sign)
Treatment depends on severity of inj*
Splenic haematoma
Assoc* w:
- splenic trauma
- infection
- haematological Dx
- neoplasms (haemangiosarcoma, lymphosarcoma)
- idiopathic
Can be subcapsular or within parenchyma
Can lead to splenic rupture esp. post trauma
Splenic abscess
- most often seen as a complication of infective endocarditis
- can be: bacterial, fungal, or parasitic origin
Splenic infarct
- blood supply to the splenic artery or one of its branches is compromised
- necrosis of supplied tissue
- most commonly caused by thromboembolic Dx & infiltrative haematologic Dx
- can also occur as result of trauma, torsion if splenic artery in ‘wandering spleen’, post surgery (pancreatectomy, liver Tx)
Pancreas: normal appearance
Shape: dumbbell, tadpole, sausage & comma-shaped
Exhogenicity: Mod echogenic but hyperechoic to adj* liver
- can be isoechoic to liver
- echogenicity inc* w age due to fatty changes
Parenchymal echotexture:
- generally homogenous, but can appear heterogeneous if there is a lot of intralobular fat
- considered more ‘coarse’ than liver
Contour: altho* it does NOT have a capsule, it has a smooth, curvilinear contour
Echogenicity ladder
Renal sinus => pancreas => spleen => liver => renal cortex
