Images courtesy of Lennard A. Nadalo, MD
Images courtesy of Lennard A. Nadalo, MD
Author
Lennard A. Nadalo, MD
Clinical Professor, Department of Radiology; University of Texas Southwestern Medical School
Consulting Staff; Envision Imaging of Allen and Radiological Consultants Association
Dallas, Texas
Disclosure: Lennard A. Nadalo, MD, has disclosed no relevant financial relationships.
Editor
Lars Grimm, MD
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, has disclosed no relevant financial relationships.
Reviewer
Jose Varghese, MD
Associate Professor
Department of Radiology
Boston University School of Medicine
Boston, Massachusetts
Disclosure: Jose Varghese, MD, has disclosed no relevant financial relationships.
Solid organ transplantation patients are becoming a small but significant proportion of the population. Their typically long period of illness prior to transplantation, extensive transplantation surgery, and posttransplantation medications result in a unique set of risk factors for a variety of disease processes. Clinicians must remain especially vigilant when presented with a transplant patient who may present with seemingly innocuous complaints. The use of immunosuppressive medications places patients at risk for a wide variety of typical and atypical infections, including fungal and mycobacterial infections.
This is an anteroposterior chest x-ray of a patient with a history of multiorgan transplantation who presents with shortness of breath. The initial chest x-ray demonstrates a right upper lobe density (arrow) consistent with a mass or lung consolidation.
What is the next diagnostic step?
A. A follow-up chest x-ray in 1 week
B. Percutaneous lung biopsy with cytology
C. Sputum sample for culture and sensitivity
D. CT of the chest with IV contrast
Answer: D. CT of the chest with IV contrast
The patient underwent a CT scan to better delineate the opacity seen on chest x-ray, which revealed an infiltrate with a mass-like pattern of consolidation (arrow). The patient was too ill to allow for long-term follow-up. Given the concern for atypical infection in this multiorgan-transplant patient, an aspiration was performed that revealed histoplasmosis. Three forms of histoplasmosis exist: acute pulmonary, chronic pulmonary, and progressive disseminated. Progressive disseminated histoplasmosis is associated with immunosuppression, especially in patients on tumor necrosis factor antagonists. These patients have dormant infections that may become reactivated to involve the lungs, central nervous system, heart, mucous membranes, or intestines.
A renal transplant patient presents with headache and diploplia. An x-ray of the sinuses reveals partial opacification of the left frontal sinus (black arrow) and ethmoid sinus (blue arrow). The primary diagnostic consideration is sinusitis, but diplopia is a rare complication with sinusitis and with severe sinusitis there should be complete opacification of the frontal sinus.
What is the next step in the diagnostic workup?
A. A follow-up paranasal sinus x-ray series in 2 weeks
B. MRI or CT of the orbits and paranasal sinuses
C. Sinus irrigation with cultures
D. Broad spectrum antibiotics
Answer: B. MRI or CT of the orbits and paranasal sinuses
MRI offers better visualization of the brain and extraocular muscles of the orbit. The next step in workup should be cross-sectional imaging; in this case, MRI. The axial T1-weighted image of the brain (left image) demonstrates opacification of the frontal sinus (yellow arrows) while the image of the orbit (right image) demonstrates a mass compressing the lateral rectus muscle (white arrow). The patient underwent an emergent orbital decompression and a biopsy of the mass that revealed mucormycosis. Mucormycosis is a fungal infection associated with poorly controlled diabetes, leukemia, lymphoma, AIDS, and organ transplantation. Infections may begin in the sinuses, as in this case, and spread to involve the orbits or cranial nerves. Inflammation may induce venous thrombosis leading to cerebral infarction.
A patient with an old organ transplant presents with recent back pain and lower extremity weakness. An MRI of the lumbar spine is ordered, which reveals destruction of the bony endplates of the L3/4 disk space (yellow arrow), enhancement of the superior L4 endplate (white arrows), and epidural soft-tissue protrusion into the spinal canal with resulting nerve root compression (black arrow).
What is the most likely etiology of these MRI findings?
A. Chronic intervertebral disk degenerative changes
B. Osteomyelitis
C. Diskitis with secondary changes of the vertebral endplates
D. Unreported acute injury
Answer: C. Diskitis with secondary changes of the vertebral endplates
The MRI findings in this transplant patient with back pain and lower extremity weakness are consistent with diskitis. There was no history of trauma, which seldom affects the disk spaces directly. Chronic degenerative disease is seldom this extensive.
The patient underwent a percutaneous CT-guided biopsy of the disk (arrow), which revealed aspergillosis diskitis. Aspergillosis is the second most common opportunistic fungal infection in immunocompromised patients. Disseminated aspergillosis is frequently associated with nonspecific symptoms that are unresponsive to antibiotic therapy. Diskitis can lead to debilitating neurologic injury and is often associated with vertebral body osteomyelitis. The patient was treated with a combination of surgical decompression and long-term antimicrobial medication.
A patient with a prior heart transplant presents with new onset of abdominal pain. The patient's laboratory results reveal elevated amylase and lipase and an abdominal CT scan reveals an enlarged heterogeneously enhancing pancreas, consistent with pancreatitis. Patients on immunosuppressive medications, especially tacrolimus, are at increased risk for pancreatitis and these agents may need to be stopped or have their dose lowered. Transplant patients may have an increased risk of developing hemorrhage or pseudocyst formation due to their decreased reparative abilities.
A renal transplant patient presents with sudden onset of abdominal pain, nausea, and vomiting. An abdominal CT reveals a normal appearing renal transplant ("RT") but there is herniation of omental fat (arrow) and an incarcerated loop of small intestine ("SI") from an incisional hernia. All patients with prior abdominal surgery are at risk for an incisional hernia, but transplant patients are at increased risk due to chronic illness prior to the transplantation, the large incision, and the diminished healing capacity while immunosuppressed. Incarcerated hernias are always a surgical emergency.
A renal transplant patient develops progressive lower extremity weakness. A sagittal T1-weighted MRI reveals an epidural enhancing mass (black arrow) while an axial precontrast image reveals a paraspinal mass (white arrow) posterior to the aorta. Surgical decompression was performed to restore neurologic function and the mass was found to be extramedullary hematopoiesis. Extramedullary hematopoiesis is the result of either ectopic hematopoietic rests or direct extension of hematopoietic marrow from the vertebrae that become stimulated during chronic anemia, chemotherapy, chronic illness, or transplantation. It can cause neurologic complications due to associated mass effect.
A liver transplant patient develops sudden onset hepatic failure with elevated liver function tests. An MR angiogram reveals thrombosis of the proximal hepatic artery (arrow). Vascular occlusion, due to thrombosis or stenosis, is one of the most serious complications of liver transplantation and may lead to rapid hepatic failure, elevated bilirubin, and mental status changes. After transplantation, the hepatic artery assumes a critical role in survival of the liver transplant in contrast to the portal vein, which is much less deleterious if thrombosed. These patients usually require emergent surgical thrombectomy because systemic anticoagulation is usually insufficient. Certain immunosuppressive agents, such as sirolimus, place patients at increased risk for thrombosis.
Several weeks after transplantation, a renal transplant patient presents with sudden onset of renal failure and tenderness over the transplant. An ultrasound reveals edema with increased renal length, a hypoechoic appearance to the kidney, and increased resistive indices of the parenchymal vessels. Biopsy reveals acute transplant rejection. Acute rejection is the most common type of transplant rejection usually within the first 3 months due to a T-cell-mediated response. Mild cases can be treated with corticosteroids, but more serious reactions may require anti-T-cell antibodies.
Several years after transplantation, a renal transplant patient presents with right lower quadrant pain and renal failure. A CT scan reveals a delayed nephrogram with poor contrast uptake confirmed by biopsy to be due to chronic rejection. Chronic rejection results in a slow, progressive deterioration of renal function due to a combination of antibody and cell-mediated rejection. The end result is progressive fibrosis of the parenchymal blood vessels. Unfortunately, this condition was minimally responsive to corticosteroids or anti-T-cell antibodies. It is a major cause of transplant loss later than 2 years post transplantation.
A lung transplant patient presents with lower back pain without associated history of trauma. A lumbar spine radiograph reveals extensive osteoporosis and an anterior wedge compression fracture of the L1 vertebral body (arrow). Pretransplantation patients may be at increased risk for osteoporosis due to organ failure and therapy (such as steroids, heparin, and loop diuretics). After transplantation, the immunosuppressive medications can cause significant bone loss: glucocorticoids increase bone loss; tacrolimus increases bone turnover; and cyclosporine increases both bone loss and turnover. Renal transplant patients may have persistent hyperparathyroidism and hypercalcemia and liver transplant patients may have persistent hypogonadism, which are all risk factors for osteoporosis.
Patients with solid organ transplants are at significantly higher risk for malignancy due to chronic immunosuppression, chronic antigenic stimulation, increased susceptibility to oncogenic viral infection, and direct neoplastic action from immunosuppressants. A patient with a renal transplant (yellow arrow) presents with sudden onset of abdominal pain. An abdominal CT reveals free fluid (black arrow) and thickening of the small bowel (white arrow). Emergency surgery was necessary to repair the bowel perforation that was found to be due to intestinal lymphoma. Transplant recipients are estimated to be at 2- to 5-fold increased risk for colon, larynx, lung, bladder, and prostate cancer, and at 10- to 30-fold increased risk for nonmelanoma skin, kidney, endocrine, and cervical cancer, as well as non-Hodgkin lymphoma.
Posttransplant lymphoproliferative disease (PTLD) is a B-cell proliferation disorder. It results from either reactivation or primary posttransplantation infection of Epstein-Barr virus in the setting of immunosuppression. The end result is plasmacytic hyperplasia, B-cell hyperplasia, B-cell lymphoma, or immunoblastic lymphoma. The resulting tumors are aggressive, rapidly progressive, and often fatal. Patients have a protean presentation including fever, lymphadenopathy, mononucleosis-like symptoms, weight loss, or central nervous system, pulmonary, or gastrointestinal symptoms. In many cases, withdrawal of immunosuppression will allow the native immune system to combat the disease and in some cases result in disease regression. A biopsy of gingival tissue with H&E staining demonstrates an infiltrate of atypical lymphoid cells consistent with PTLD.
A patient with a double organ transplant (heart and kidney) presents with hematuria and decreased renal function. Hematuria can be especially difficult to work up in transplant patients due to the increased risk for infection, malignancy, and rejection in addition to the more usual causes of hematuria (such as nephrolithiasis). A renal ultrasound of the transplant kidney demonstrates a solid mass (yellow arrows) with irregular borders that was proven to be a renal cell carcinoma ("RC"). Transplant ultrasound is also useful to evaluate for cyclosporine and tacrolimus nephrotoxicity-- which is the result of vasoconstriction and renal ischemia -- as a cause of hematuria in this patient population.
Images courtesy of Lennard A. Nadalo, MD
Author
Lennard A. Nadalo, MD
Clinical Professor, Department of Radiology; University of Texas Southwestern Medical School
Consulting Staff; Envision Imaging of Allen and Radiological Consultants Association
Dallas, Texas
Disclosure: Lennard A. Nadalo, MD, has disclosed no relevant financial relationships.
Editor
Lars Grimm, MD
House Staff
Department of Internal Medicine
Duke University Medical Center
Durham, North Carolina
Disclosure: Lars Grimm, MD, has disclosed no relevant financial relationships.
Reviewer
Jose Varghese, MD
Associate Professor
Department of Radiology
Boston University School of Medicine
Boston, Massachusetts
Disclosure: Jose Varghese, MD, has disclosed no relevant financial relationships.
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