Diagnostic ultrasound ( PDFDrive )

CHAPTER 18 Organ Transplantation 683
P
A
B
C
P
D E F
P
P
P
G H I
FIG. 18.68 Fluid Collections. (A)-(C) Hematoma. (A) Sagittal and (B) transverse sonograms show complex collection with internal echoes
and strands. (C) Correlative CT shows hematoma in left upper quadrant that extends to pancreas (P). (D)-(I) Pseudocysts in three patients.
Patient 1: (D) Sagittal sonogram shows complex epigastric cyst with internal septation. Patient 2: (E) Sagittal sonogram shows complex collection
adjacent to pancreas (arrowheads). (F) Correlative CT scan shows collection extending into pancreatic head (P) and associated with free luid
(arrows). Patient 3: (G) Sagittal sonogram shows large pseudocyst with internal echoes surrounding pancreatic tail (P). (H) and (I) Seroma.
Transverse sonogram and correlative CT scan show large, anechoic cystic structure surrounding pancreatic body (P). The wall enhanced on CT
scan. The collection was sterile on aspiration.
not surprising that agents that suppress T-cell activity are associated
with a higher risk of PTLD. By the same token, a larger
total number of immunosuppressant agents used by a patient
may result in an increased risk of PTLD. 104
he incidence of PTLD is bimodal, with the initial peak in
the irst year ater transplantation and the second peak approximately
4 to 5 years ater transplantation. 105 Biologically, the two
peaks have a very diferent clinical course. he early-onset disease
has a more favorable course, is pleomorphic in subtype, and has
a positive response to reducing the level of immunosuppression.
Late-onset disease is more commonly seen in conjunction with
EBV infection, a monomorphic subtype, and an aggressive disease
course. here is a higher mortality, and the disease is oten resistant
to chemotherapy. 106
PTLD can be categorized depending on its primary location
into either nodal disease (22%) or extranodal disease (81%).
Nodal disease is either mediastinal or retroperitoneal in location.
he involved lymph nodes have an abnormal appearance,
showing a hypoechoic thickened cortex with an absent or
lattened fatty hilum (Figs. 18.69 to 18.72). Extranodal disease