radiologic approach to disease of spleen

1. Imaging Diseases of Spleen
ADAMA COMPREHENSIVE SPECIALIZED HOSPITAL MEDICAL
COLLEGE
DEPARTMENT OF RADIOLOGY
Presenter: Abel Girma (MD, Radiology
Resident )
Moderator: Abdi Alemayehu (MD, Radiologist )
Augest 2022

2. OUTLINE
Introduction
Imaging Modalities
Splenomegaly
Splenic Lesions

3. INTRODUCTION
The spleen is the largest ductless gland and the largest single lymphatic
organ in the body. It is mesodermal in origin.
has been considered a “forgotten organ,”

4. IMAGING MODALITIES
 CT and US remain the major techniques used to image the splenic
parenchyma
 With new techniques MR plays an increasing role.
 Technetium sulfur colloid radionuclide scanning images both the liver and
the spleen and can be used to confirm the presence of functioning
splenic tissue, which is important in the diagnosis of selenosis.

5. Computed Tomography (CT)
 Intravenous contrast should be used to image the spleen.
 Multiphase imaging is appropriate in most settings.
 If the primary concern is for vascular disease, early arterial imaging can be
used. In the nonemergency setting,
 Oral contrast may help delineate primary splenic disease from adjacent gastric,
small bowel, or colonic disease.
Single phase imaging should be performed in the portal venous phase

6. Inhomogeneous Splenic
Enhancement
Present in CT, MRI, or ultrasound
imaging
There are 3 general patterns of enhancement :
• Arciform: alternating bands of low and high density which may look like rings or
zebra stripes
• focal: single area of low density
• diffuse: mottled appearance
These three different patterns are primarily due to splenic enlargement, age of the
patient and contrast injection rate

8. • The diagnosis of splenic enlargement on imaging studies is usually made
subjectively.
• The normal spleen size for any individual is substantially influenced by
demographic factors, sex, and body habitus;
• Findings that suggest splenomegaly are
• (1) Any spleen dimension greater than 13 cm,
• (2) Inferior spleen tip extending more caudally than the inferior liver tip, or
• (3) Inferior spleen tip extending below the lower pole of the left kidney.
• Complications of splenomegaly include hypersplenism and spontaneous splenic
rupture
Splenomegaly

9. Most do not produce a change in spleen density, so differentiation
is based upon associated imaging findings or on clinical
evaluation.

10. Splenomegaly. Coronal T2WI of a patient with
cirrhosis shows the spleen (S) to be enlarged
measuring 20 cm in length. The spleen is
larger than the liver (L) and extends
into the central abdomen.
Liver cirrhosis with splenomegaly

11. MASSIVE SPLENOMEGALY
O'Reilly R. Splenomegaly in 2,505 Patients in a Large University Medical Center from
1913 to 1995. 1913 to 1962:
Defined Variably including….
• spleen is 5 standard deviations above the mean normal volume
• heavier than 1.0 kg or 1.5 kg ,
• >14.5 cm true craniocaudal measurement on coronal CT,
• >18 cm on clinical exam , or at/below the umbilicus, extending into the pelvis and/or across the
midline
Prassopoulos P, Daskalogiannaki M, Raissaki M, Hatjidakis A, Gourtsoyiannis N. Determination of Normal
Splenic Volume on Computed Tomography in Relation to Age, Gender and Body Habitus. Eur Radiol. 1997;

12. Small or shrunken Spleen
Causes
44-year-old woman with sickle
cell disease and a small calcified “shrunken”
spleen (arrow)

13. SPLENIC CALCIFICATION CAUSES
can occur in various shapes and forms and can occur from a
myriad of etiological factors.

14. Splenic Lesions

15. • the exact differential diagnoses for splenic lesions are important for
selection of appropriate strategies
• It often is difficult to differentiate benign splenic lesions from
malignant tumors for the following reasons:
Splenic Lesions cont…
(a) the radiologic features of many splenic lesions overlap,
(b) splenic lesions tend to manifest with vague clinical symptoms,
and
(c) abnormalities and primary tumors of the spleen are
uncommonly encountered in daily clinical practice.

16. Splenic Lesions Continued
Other clinical features, pathologic findings, and specific radiologic findings such as margin
and multiplicity are also helpful in differentiating various splenic lesions;
1. the nature of the lesion and
2. the degree of lesion enhancement after contrast material
injection
key elements for narrowing the range of the differential diagnosis.

18. Summary

19. CYSTIC LESIONS

21. Simple Splenic Cysts
Complications are rare and include hemorrhage, rupture and infection
The pathogenesis is unclear, with support for the theories of
• congenital mesothelial invagination,
• endodermal inclusion, and
• Acquired subclinical trauma with mesothelial displacement

22. Simple Splenic Cyst on Ultrasound
Usually shows an anechoic to
hypoechoic well defined
intrasplenic lesion.
Internal echoes may be present
due to debris.
Their margin may be echogenic
with distal shadowing due to
calcifications

23. Splenic Cyst on CT scan
Typically shows a hypoattenuating
relatively well-defined intrasplenic lesion.
The wall is thin and has a sharp
demarcation to the splenic parenchyma.
There is no rim or internal enhancement.

24. Epithelial cyst in a 28-year-old woman with left upper quadrant pain.
On an axial T2-weighted image, the cyst is well circumscribed and thin walled (arrow) with
homogeneous hyperintensity (*)

25. PSEUDOCYSTS
• acquired cystic lesions not delineated by a true epithelial
wall.
• thought to account for 80% of benign non-parasitic cysts
of the spleen
• Immunohistochemistry for pancytokeratin can be
performed to confirm the absence of an epithelial lining.

26. RADIOLOGIC FEAATURES OF PSEUDOCYSTS

28. Splenic peliosis
Peliosis is an important condition to be aware of because rupture of the blood-filled cysts on the spleen
surface can lead to hemorrhagic peritonitis and ultimately be fatal.
• Peliosis is an unusual benign disorder characterized by the presence of irregular cystic blood-filled
cavities.
• Fewer than 100 cases have been described in the literature.
• Documented causal associations include the oral contraceptive pill, anabolic steroids, advanced
tuberculosis and human immunodeficiency virus (HIV).

29. Peliosis Continued
Ultrasound appearances include an echogenic mass
with numerous poorly defined foci of varying
hypoechogenicity.
The larger lesions demonstrate moderate posterior
acoustic enhancement.
On non-contrast-enhanced CT images:
the appearances are of a hypoattenuating,
multiloculated lesion with well-defined septa.
On contrast-enhanced CT images, the lesion
demonstrates significant enhancement with loss of
definition

30. Parasitic (Echinococcal) Cyst
The reported prevalence ranges from 0.9% to 8%.
Splenic echinococcal cysts develop through systemic dissemination or
intraperitoneal spread of a ruptured hepatic echinococcal cyst.
Patients can present with no symptoms, abdominal pain, splenomegaly, or fever
Imaging findings are similar to those of hepatic hydatid disease and range from purely cystic lesions to a
completely solid appearance

31. Large cystic splenic lesion with peripheral
wall calcifications and multiple internal
smaller daughter cysts

32. Second image shows distortion of the multilocular cyst (∗) due to expansile
heterogeneous hyperattenuating blood products (arrow) within and around the
spleen, consistent with rupture

35. Infections
Splenic abscesses can be bacterial, mycobacterial, or
fungal and
• hematogenous seeding,
• direct extension,
• sequelae of trauma, or
• prior infarcts.
The subacute or chronic inflammatory infiltrate can be seen as a hypointense rim around these lesions
with all MRI sequences, corresponding to iron-loaded macrophages
Acute micro abscesses are not associated with avid rim enhancement, presumably owing to
inability of the neutropenic patients to mount a robust inflammatory response;

36. • Abscesses appear as single or multiple low-density masses with ill-defined
thick walls. US commonly demonstrates internal echoes caused by
inflammatory debris.
• On unenhanced CT images, splenic abscesses are spherical or lobulated
hypodense lesions, which rarely contain gas.
• They may contain gas or demonstrate air fluid levels.
• Perisplenic fluid collections and left pleural effusions are common.
• Image-guided aspiration confirms the diagnosis.
• Treatment is by catheter drainage or splenectomy.
Infections Con’t

37. On gray-scale
ultrasonography, a
heterogeneous low-echoic
lesion in the inferior
aspect of the spleen
(arrowheads) is seen.
On
contrast enhanced
transverse CT image, an
ill-defined low-attenuating
lesion is noted in the
spleen.

39. Axial contrast-enhanced CT in a 66-year-
old man with splenomegaly and a 10-cm
splenic abscess with air/fluid level (arrow)
caused by gas-forming organisms.
Splenic abscess in a 35-year-old male.
Contrast enhanced transverse CT image
shows a thick-walled cystic lesion with
internal septa in the spleen (arrow). Note
layered enhancement of the
cyst wall and reactive ascites.

40. Fungal infections
• Are also more common in the immunocompromised population and large fungal abscesses may have a
target appearance which relates to their structure:
(1) a central nidus of necrotic hyphae, hypoechoic at US and hypodense at CT;
(2) a concentric band of viable fungal elements, hyperechoic at US and hyperdense at
CT; an
(3) a surrounding circular area of inflammation, hypoechoic at US and hypodense at
CT.
• The peripheral area of inflammation may demonstrate enhancement on CT or MR after
contrast administration.
Infections Con’t

41. C. Contrast-enhanced
CT shows numerous,
subcentimeter,
hypodense nodular
lesions throughout the
liver and spleen.
Disseminated Candida infection in a patient with acute myelogenous
leukemia
A. Transverse ultrasound
image shows
multiple, small,
hypoechoic lesions in the
splenic parenchyma.
B. a high-frequency (5-
12 MHz) linear
transducer
demonstrates a small,
hypoechoic nodule
with a central
echogenic nidus.

42. An immunocompromised
patient with ‘target’-type fungal abscesses (arrowheads).

43. Fungal abscess in a 20-year-old female. On CECT image, innumerable low-
attenuating lesions are detected
in the spleen. Several peripherally enhancing low-attenuating nodular lesions
are also seen in the liver (arrowheads).

44. Splenic TB
• Splenic involvement is common in patients with disseminated TB.
• It is usually widely distributed in a fine military pattern and TB lesions may appear
on CT as tiny low density foci scattered throughout the whole spleen.
• On ultrasound they may present with numerous increased
echo-reflectivity foci creating a ‘bright spleen’ or ‘pepper pot’
pattern which may persist after treatment.
Infections Con’t

45. • Splenic TB may also present with larger focal lesions as
pseudotumor or tuberculomas and this may occur without overt
pulmonary or gastrointestinal tract involvement.
• Splenomegaly with multiple nodules(1–3 cm in size),
hypoechoic at US and hypodense at CT, scattered throughout
the spleen.
• Large chronic tuberculoma lesions often calcify.
Splenic TB

46. • When the nodules or granulomas heal, they can be become calcified and
appear as small, scattered, discrete, bright echogenic lesions with
posterior shadowing in an otherwise normal spleen.
• These probably are the most frequently encountered nodular splenic
lesions.
Splenic TB

47. coronal extended–field of view images in a young AIDS
patient with active miliary TB. Numerous tiny
hypoechoic nodules are present throughout the
enlarged spleen.

48. Miliary Tuberculosis of the Spleen.
(A) Coronal and (B) high-resolution linear array ultrasound images show multiple
tiny echogenic foci of tuberculous granulomata in this patient with active
tuberculosis.

49. Axial (A) and coronal (B) contrast-enhanced CT in a 53-year-old man with tuberculosis
and mild splenomegaly and multiple hypodense
tuberculous splenic lesions.
Disseminated miliary
tuberculosis.
Contrastenhanced CT demonstrates
multiple hypodense nodules. Notice the
associated para-aortic and retrocrural
hypodense lymphadenopathy (arrow).

50. Calcified tuberculosis in a 33-year-old female. (a) Grayscale
ultrasound image shows dense hyperechoic lesions in the spleen
(arrowheads). (b) Contrast-enhanced transverse CT image shows
dense calcified lesions in the spleen (arrows).
Long-standing tuberculomas of caseation necrosis turn to
calcified granulomas
Splenic artery calcification

51. Pneumocystis jiroveci
pneumonia. Longitudinal
ultrasound image
demonstrates multiple,
punctate calcifications after
successful treatment.
Microabscesses in the Spleen. Multiple lucent
defects of varying size in the spleen (S) of this
patient with AIDS are attributable to
Pneumocystis jiroveci
infection.(Both CT)

52. Multiple splenic nodular lesions
• multiple small defects in the spleen, usually 5 to 10 mm
but up to 20- 30 mm, in size.

53. • are present in about 10% of patients with portal hypertension.
• These are deposits of hemosiderin and calcium due to
microhemorrhage followed by fibroblastic reaction.
• Multiple tiny echogenic foci without acoustic shadowing.
• and are seen at MR as tiny foci of low signal intensity on both T1w and
T2w images.
• They do not enhance.
Gamna-Gandy bodies

54. On ultrasound (A) multiple increased echo-reflectivity lesions caused
by small focal hemorrhages arising in portal venous
hypertensions (Gandy-Gamna bodies). They are often not
well visualised on CT (B) unless they calcify and are also
overlooked on spin-echo-based T2w imaging (C) but ‘bloom’ owing to
their susceptibility effect on gradient-echo imaging (D).

55. Gamna-Gandy body in a 58-year-old female with liver
cirrhosis. (a–c) In-phase (a), opposed-phase (b), and T2-
weighted (c) MR images show disseminated dark signal
intensity lesions in the spleen according to the
hemosiderin deposition in the spleen.

56. LYMPANGIOMA
Lymphangiomas are rare malformations of splenic lymphatic channels
characterized by anastomosing, dilated, thin-walled, fluid-filled cystic
structures, similar to hemangiomas.
Most occur in the pediatric population and are considered to reflect
abnormal congenital development .
An alternative hypothesis suggests that lymphangiomas reflect telangiectasia
of lymphatic channels obstructed by hemorrhage or inflammation
The clinical manifestation depends on the size; most are incidental and asymptomatic.
However, large or multifocal lymphangiomas can result in splenomegaly, left upper quadrant
pain, and nausea

57. RADIOLOGIC FEATURES

58. (C) US image along the long axis of the spleen shows multiple unilocular or multilocular anechoic or hypoechoic
spaces (arrows) of various sizes. (D) Coronal contrast-enhanced CT image shows enlargement of the spleen with
numerous well-circumscribed, thin-walled, unilocular or multilocular hypoattenuating lesions (arrows) of various
sizes without enhancement.

59. SOLID SPLENIC LESIONS

60. Hemangioma
• Hemangioma is the most common primary neoplasm of the spleen, found in
14% of patients on autopsy series.
• Microscopically, it consists of blood-filled space lined by endothelium.
• The size of the blood-filled space can be various which manifest from large
(cavernous hemangioma) to very small (capillary hemangioma), although,
cavernous hemangioma is more common.
• Capillary hemangiomas tend to manifest as solid masses, whereas
cavernous hemangiomas are often accompanied with cystic components.

61. Imaging Features

63. Hemangioma in Two Patients. (A) Small (1.4-cm), well-
defined, rounded, echogenic lesion (arrow) is similar to
the typical liver hemangiomas. (B) Coronal ultrasound
scan shows multiple echogenic splenic hemangiomas of
different sizes in the spleen. Note the calcified splenic
artery adjacent to the vein.

64. Sagittal US in a 36-year-old
woman with a 3.5-cm
hyperechoic splenic mass
(arrows) representing a
hemangioma.

65. Incidentally found splenic mass in a 39-year-old male. (a)
NECT image shows an iso-attenuating focal splenic lesion compared to
the adjacent spleen, Portal venous (b) and delayed phase (c)
transverse CT images show a well-defined mass with
progressive homogeneous enhancement

66. Cavernous hemangioma in a 69-year-old male. (a)
Noncontrast transverse CT image shows a multiloculated
low-attenuating lesion in the spleen. (b) On portal venous
phase transverse CT image, the multiloculated cystic lesion
does not show any enhancement except internal septation
(arrowheads).

67. Hemangioma Spleen. Postcontrast CT shows this splenic hemangioma
(arrow) to be an inhomogeneous, minimally enhancing, lobulated, low-
attenuation mass.

68. • Lymphoma is the most common malignant tumor
involving the spleen.
• Secondary splenic involvement is common in many
lymphomas, whereas primary splenic lymphoma is relatively
uncommon.
• Spleen size alone is not a reliable sign of
lymphomatous involvement.
• Up to a third of patients with splenomegaly have no
evidence of splenic lymphoma at histological examination. In
addition, up to a third of patients with lymphoma of any kind have
histological involvement of the spleen without splenomegaly.
Lymphoma

69. Lymphoma Cont
• Patterns of involvement that are visible on imaging studies
include
• Normal appearing spleen
• Diffuse splenomegaly,
• Multiple masses of varying size,
• Miliary nodules resembling micro abscesses,
• Large solitary mass, and
• Direct invasion from adjacent lymphomatous
nodes.
• Adenopathy is frequently evident elsewhere in the
abdomen when the spleen is involved with lymphoma.
• Lymphoma is a common predisposing condition for
splenic infarction.

70. • Splenic lymphomas may present at US with three different patterns:
• (1) diffusely heterogeneous with disruption of the normal splenic
ultrasound appearance;
• (2) small, nodular, hypoechoic lesions; and
• (3) large, focal, hypoechoic lesions that may be cyst like.
• Cyst-like lesions may be markedly hypoechoic and resemble simple cysts;
however, they lack posterior acoustic enhancement. A cystic appearance
may also be due to necrosis.
Lymphoma Cont

71. Patterns of Lymphoma in Different Patients. (A) Numerous small nodules
resulting from T-cell lymphoma in an enlarged spleen. (B) Multiple solid nodules in a
patient with follicular lymphoma. (C) Bulky solid mass in a patient with non-Hodgkin
lymphoma. (D) Large, poorly deined mass caused by B-cell lymphoma replacing the
spleen and extending beyond the normal contour..
Lymphoma may also
involve the spleen
diffusely without focal
abnormalities

72. • CT is unreliable in the diagnosis of splenic lymphoma because a normal-
appearing spleen may still contain tumour cells.
• CT is only 65% sensitive in demonstrating splenic involvement with
lymphoma.
• Demonstration of splenic hilum adenopathy and focal splenic enhancing defects, in
addition to splenomegaly, are more reliable CT indicators of lymphomatous
involvement.
Lymphoma Cont
• At MR, areas of lymphoma involvement appear as slightly hypointense foci on T1w and
hyperintense foci on T2w images.
• In similar fashion to CT, MR imaging cannot reliably depict
infiltrative lymphoma, because both normal spleen and lymphomatous infiltrated
spleen may have similar T1w and T2w signal intensity.

73. A 72-year-old female with diffuse large B-cell lymphoma.
Splenomegaly with diffuse low attenuation is noted both on
arterial (left) and portal (right) phase CT images. There is
no discernible focal lesion in the spleen

74. Hodgkin’s lymphoma in a 42-year-old man. A. The sagittal
sonogram reveals an enlarged spleen containing multiple
ill-defined, hypoechoic lesions. B. The CT scan of
the upper abdomen demonstrates multiple low-density
masses.

75. Axial contrast-enhanced CT in a 66-year-old woman with
almost complete splenic replacement by a
primary lymphomatous mass (arrows). There is an
incidental hemangioma in the liver (small arrow).

76. • Angiosarcoma is very rare but is still the second
most common malignancy arising in the spleen.
• The tumor is aggressive, usually presenting with
widespread metastases, especially to the liver.
• poor prognosis.
Angiosarcoma

77. Angiosarcoma
Imaging features

78. Angiosarcoma. Transverse image shows multiple poorly
defined hypoechoic lesions. Other sonographic findings
include a heterogeneous echotexture, complex masses,
and splenomegaly.

79. Splenic angiosarcoma in a 33-year-old female. Dynamic
contrast-enhanced CT images demonstrate
a heterogeneously
enhancing mass-like lesion replacing nearly whole
portion of the enlarged spleen

80. Splenic angiosarcoma. A heterogeneously enhancing mass
expands the spleen on CT (A) arterial phase, (B) portal phase and
equilibrates on the delayed phase (C)….hemagioma like… FDG PET-
CT demonstrates the associated increased metabolic activity (D).

81. Angiosarcoma Spleen. Axial T2WI shows nearly complete replacement of the
parenchyma of the spleen (S) with numerous heterogeneous high-signal nodules of
various sizes. Pathology confirmed nearly complete involvement of the spleen with
angiosarcoma.

82. • Splenic metastases are relatively uncommon.
• Melanoma metastases account for 50% of all cases; the
remaining 50% are mainly due to adenocarcinoma of breast, lung,
colon, ovary, endometrium, and prostate.
• Melanoma metastases commonly appear cystic.
• At US, metastatic lesions are mainly reduced echo
reflectivity, although increased echo-reflectivity lesions
can occur.
• CT-Metastases appear as single or multiple low-density
masses. The CT features of a cystic splenic
metastasis can be identical to those of a benign
cyst.
Splenic Metastases

84. Portal phase CT in two different patients
(A, B) with splenic melanoma
metastases demonstrates relatively non-
specific multiple low attenuation lesions
within the spleen.
Hyperechoic splenic metastasis
from melanoma. Ultrasound
demonstrates multiple hyperechoic masses
throughout
the spleen.

85. HAMARTOMA

86. Sclerosing
angiomatoid nodular
transformation
(SANT)

90. Splenic Vascular Disorders

91. Splenic Infarction
• Infarction is produced by occlusion of the main or branch splenic arteries….w/c
are end arteries.
• Venous infarction also occurs in portal venous hypertension or splenic vein
occlusion.
• Splenomegaly, especially when caused by lymphoma, is a predisposing
condition.
• Infarcts classically appear as wedge-shaped defects in the splenic
parenchyma.
• However, multiple infarcts may fuse, and the wedge shape may be lost.
• The key finding is extension of the abnormal parenchymal zone to an
intact splenic capsule.
• The imaging appearance depends on the time after onset.

93. Splenic Infarct. Triangular hypoechoic infarct
(arrow) in the superior aspect of the spleen
extends to the splenic capsule.

94. Splenic Infarct. (A) Coronal image shows a well-
defined hypoechoic central area reaching the
splenic capsule medial and lateral in a patient
with splenomegaly. (B) Corresponding CT scan
after intravenous contrast demonstrates the
wedge-shaped nonenhancing area in keeping
with an infarct.

95. Axial contrast-enhanced CT in an
83-year-old woman with peripheral
hypoattenuating nonenhancing
splenic defects (arrows) caused
by infarcts.
Splenic Infarction. Postcontrast CT in a
patient with CLL shows multiple infarctions
(I) within the spleen (S). Note how each
lesion extends to the splenic
capsule.

96. Chronic splenic infarct. Contrast-enhanced CT
demonstrates a classic wedge-shaped, peripherally
nonenhancing, hypodense area. The base of the infarct is
at the splenic capsule, and the apex points toward the
hilum. Some volume loss and capsular
retraction indicate a chronic infarct.

97. Splenic Artery Aneurysm
Predisposing factors for aneurysm formation include
Medial degeneration, fibromuscular dysplasia, portal hypertension,
and pregnancy.
Trauma, pancreatitis, and infection can lead o the formation of
pseudoaneurysms.
The timing and cut-off size for treating splenic artery aneurysms are controversial,
although aneurysms are generally treated when the size exceeds 2–3 cm

98. a peripherally calcified splenic artery aneurysm (arrow) which is
markedly enhancing in the arterial phase involving the splenic
artery

99. References:
1. Algorithmic Approach to the Splenic Lesion Based on RadiologicPathologic Correlation,
RadioGraphics 2022; 42:683–701
2. Cross-Sectional Imaging of the Abdomen and Pelvis, A Practical Algorithmic Approach /
Khaled M. Elsayes, 2015
3. https://radiopaedia.org/articles
4. Carol Rumack, diagnostic ultrasound 5th Edition
5. Cross-sectional Imaging of Splenic Lesions, Radiographics 2018.
6. Requisites GI imaging , 4th edition

100. THANK YOU