Usually located within peritoneal cavity (greater omentum, bowel serosa, parietal peritoneum, undersurface of diaphragm)
Less common locations include thorax (usually after diaphragmatic rupture) and subcutaneous soft tissues
• MDCT: Multiple nodules or masses scattered throughout abdomen or pelvis (usually peritoneal cavity)
Should follow appearance of spleen on all phases of enhancement
Slightly hypoattenuating (5-10 HU less) compared to liver on NECT, striated enhancement on arterial phase, and homogeneous enhancement on venous/delayed phases
• MR: Follows appearance and enhancement of normal spleen on all sequences
• Can mimic peritoneal carcinomatosis or primary malignancies on CT and PET
• No other clinical significance in most cases
• Most patients are asymptomatic, but rarely, symptoms are due to hemorrhage, rupture, torsion, infarction, or bowel obstruction
(Left) Axial CECT demonstrates absence of the spleen (patient had a history of prior splenectomy for trauma) with small enhancing nodules in the left upper quadrant. Splenosis is not infrequently seen in close proximity to the splenectomy bed.
(Right) Axial CECT in the same patient shows additional splenic implants along the serosal surface of the left colon and along the posterior margin of the right liver lobe. Splenosis is most commonly seen within the peritoneal cavity, with extraperitoneal splenosis more rare.
(Left) Axial CECT in a patient with remote history of abdominal trauma shows multiple soft tissue nodules along the peritoneal surfaces, which might be mistaken for carcinomatosis, but represent splenosis.
(Right) Axial CECT shows an enhancing soft tissue nodule in the left cardiophrenic angle. The patient had a distant history of traumatic splenic injury with diaphragmatic rupture, the most common reason for thoracic splenosis. Thoracic splenosis is quite rare compared to abdominal/pelvic splenosis.
TERMINOLOGY
Definitions
• Dissemination of splenic tissue into ectopic locations following splenic rupture (either traumatic or iatrogenic)
IMAGING
General Features
• Location
Most common in abdomen/pelvis (65% of cases)
– Usually located within peritoneal cavity (greater omentum, bowel serosa, parietal peritoneum, undersurface of diaphragm)
– Involvement of extraperitoneal spaces uncommon
Can occur in virtually every compartment of body
– Less common locations include thorax (usually after diaphragmatic rupture), subcutaneous soft tissues, and even intracranial cavity
• Size
Few mm to 12 cm; usually < 3 cm
• Morphology
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Usually located within peritoneal cavity (greater omentum, bowel serosa, parietal peritoneum, undersurface of diaphragm)
Less common locations include thorax (usually after diaphragmatic rupture) and subcutaneous soft tissues
in the left upper quadrant. Splenosis is not infrequently seen in close proximity to the splenectomy bed.
along the serosal surface of the left colon and along the posterior margin of the right liver lobe. Splenosis is most commonly seen within the peritoneal cavity, with extraperitoneal splenosis more rare.
along the peritoneal surfaces, which might be mistaken for carcinomatosis, but represent splenosis.
in the left cardiophrenic angle. The patient had a distant history of traumatic splenic injury with diaphragmatic rupture, the most common reason for thoracic splenosis. Thoracic splenosis is quite rare compared to abdominal/pelvic splenosis.
