Author's Accepted Manuscript
Letter From the Editor: The Great Mimickers in Radiology Gabriela Gayer MD
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S0887-2171(14)00022-5 10.1053/j.sult.2014.03.001 YSULT579
To appear in: Semin Ultrasound CT MRI
Cite this article as: Gabriela Gayer MD, Letter From the Editor: The Great Mimickers in Radiology, Semin Ultrasound CT MRI , 10.1053/j.sult.2014.03.001 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
1 Letter From the Editor: The Great Mimickers in Radiology Many diseases have been referred to as 'Great Imitator' or 'Great Mimicker'. For the sake of accuracy I looked up the definition in The Dictionary of Modern Medicine (JC. Segen, CRC Press; 1992): "The Great Imitator is a phrase used for medical conditions that feature nonspecific symptoms and may be confused with a number of other diseases. Most great imitators are systemic in nature." The list of diseases referenced is pretty long and includes about 15 entities, among which are quite a few that we, radiologists, rarely encounter since the diseases do not exhibit abnormal imaging findings (e.g. Lyme disease or fibromyalgia). The list of 'Great imitators' for radiologists, is quite different since it is based on imaging findings and not on signs and symptoms. This issue is devoted to such entities, the great imitators in radiology, in order to increase awareness of these conditions and familiarize radiologists with their imaging features. The issue opens with an article on Tuberculosis (TB), a disease that has plagued humankind worldwide for thousands of years. Even now TB still presents an immense health problem in the developing world and remains a healthcare challenge in the developed world. TB results in an estimated 1.7 million deaths each year and the worldwide number of newly diagnosed cases (more than 9 million) is higher than at any other time in history. This review is a collaboration between Drs. Prapruttam and Harisinghani and their colleagues from the Department of Radiology, Massachusetts General Hospital, Boston, and their associates from India. India had the highest total number of TB cases worldwide in 2010, and this collaboration has enabled the inclusion of outstanding illustrations of TB in virtually every organ.
2 Although imaging alone is insufficient in establishing a conclusive diagnosis of TB, familiarity with radiologic manifestations of TB is vital in order for radiologists to alert clinicians to consider tuberculosis in the differential diagnosis. Compared to TB, Sarcoidosis is a much "younger" disease, first described in 1877. In the nearly 150 years since then, many factors and agents have been implicated; however, the exact pathogenesis of the disease remains unknown. Similar to TB, pulmonary involvement is very frequent and many other organ systems (e.g. musculoskeletal, gastrointestinal) may also be involved. The next article spearheaded by Dr. Priya Suresh and her colleagues from the Department of Radiology, Derriford Hospital, in Plymouth, UK, is a casebased systemic approach looking at various systemic manifestations of the disease presenting real clinical encounters using various imaging modalities. Imaging plays a crucial role in supporting the diagnosis, directing treatment and localizing sites for biopsy to confirm the diagnosis. Another systemic disorder that can involve any organ or tissue is Amyloidosis, a rare systemic disease caused by the deposition of abnormal proteins in extracellular soft tissues. It can present with a wide spectrum of symptoms, depending on the organ involved (e.g. chronic cough, dyspnea, splenomegaly). Similarly the imaging findings of Amyloidosis vary according to the infiltrated tissue. The non-specific clinical and imaging characteristics of the disease emphasize the role of the radiologist in raising and including Amyloidosis in the differential diagnosis in the appropriate setting. Drs. Siakallis form Attikon University Hospital in Athens, Greece, and his associates Drs. Tziakouri-Shiakalli and Georgiades from Nicosia,
3 Cyprus, have contributed an exquisitely illustrated review with biopsy-proven Amyloidosis in practically every organ. The abdominal manifestations of IgG(4)-related disease are the subject of the next article. This rapidly emerging disorder is an infiltrative process that can affect various abdominal organs - most commonly the pancreas, but also the bile ducts, gallbladder, kidneys, retroperitoneum and mesentery. The outstanding review and beautiful collection of figures by Dr. Kim and collaborators from Toronto General Hospital, Canada, high lights the challenge for radiologists. Many of the examples include the striking follow-up images, obtained after steroid treatment, showing complete resolution of the lesions. Although the diagnosis is based on a combination of radiologic, serologic, and histologic findings, the radiologist plays an important role in raising the diagnosis of this infiltrative process and thus preventing unnecessary invasive procedures. Unlike the conditions discussed above, extramedullary hematopoiesis (EMH) is not defined as a disease but rather represents a compensatory response to various chronic hematological disorders that result in ineffective hematopoiesis in bone marrow. EMH occurs most often in the spleen and liver but can also involve lymph nodes, pleura, lungs, gastrointestinal tract, breast, skin, brain, kidneys, and adrenal glands. Involved organs appear enlarged on imaging studies (e.g. hepatosplenomegaly). EMH may also present as masses in various sites, most commonly paraspinal masses. These imaging findings may easily be mistaken for a lymphoproliferative process or a neoplasm and therefore tissue biopsy may be required to exclude an alternative diagnosis. Knowledge of the patients’ clinical history is essential for
4 the radiologist to suggest this diagnosis. Drs. Orphanidou-Vlachou, TziakouriShiakalli from Nicosia General Hospital and Dr. Georgiades from the American Medical Center in Nicosia, Cyprus have provided a thorough review with outstanding illustrations exemplifying the many manifestations of EMH. Castleman disease is a rare illness that affects mainly lymph nodes and is also known as giant lymph node hyperplasia and angiofollicular lymph node hyperplasia. This disorder, initially described in 1956, can occur in two different forms - a localized form, referred to as unicentric or a more widespread variety, multicentric Castleman disease. Drs. Bonekamp, Hruban, and Fishman, from The Johns Hopkins University in Baltimore, describe the wide range of symptoms, radiological appearance, treatment and prognosis of both forms of Castleman disease. Like many other disorders included in this issue, the radiological diagnosis of this disease requires familiarity with the spectrum of imaging findings, combined review of these findings with the clinical history of the patient, and a high index of suspicion. Malignant melanoma is an aggressive neoplasm that can involve virtually every organ system. The next article provides a comprehensive review of the various appearances of melanoma involving the chest and abdomen. The typical and atypical CT manifestations of the disease and the similarity of these findings to those of other disease entities grant melanoma the term ' The Great Imitator'. Imaging plays a major role in these patients, initially for the diagnosis, and subsequently for staging, and surveillance. The review by Drs. Chang and Desser from Stanford University School of Medicine, CA and Dr. Menias from Mayo Clinic School of Medicine, Scottsdale, AZ, illustrates the spectrum of imaging findings on US, CT, PET/CT and MRI. It also high
5 lights the role that newer modalities such as contrast-enhanced ultrasound and whole body magnetic resonance imaging may play in the future. The last two reviews do not focus on a single disease but concentrate on a certain body area and explore processes with overlapping imaging findings that affect these sites. The muscular system is comprised of about 700 named muscles that make up roughly half of a person’s body weight. There are several tumors and tumorlike conditions with variable biological behavior that may involve the skeletal musculature. Dr. Surov from Martin-Luther-University Halle-Wittenberg, and Dr. Weber from the University Hospital Heidelberg, Germany, describe the spectrum of lesions that affect the skeletal musculature. Various benign and malignant muscle lesions can manifest with identical radiological patterns. The authors divide these processes into separate categories (discrete intramuscular masses, lesions manifesting as diffuse muscle enlargement, etc) and point to helpful features that serve as guidelines to narrow the differential diagnosis, although biopsy and histologic examination is often necessary. Superb figures, applying all imaging modalities, complement and exemplify a wide range of lesions. The last article sheds light on the many disorders that involve a much more specific site in the body - the renal sinus. Over the last years I have encountered in my clinical practice several different processes affecting this area that were not recognized or not accurately diagnosed, until histology was available and revealed the correct diagnosis. Similar to many other processes covered in this issue, the correct diagnosis may be reached when the clinical information is available, the imaging findings are carefully analyzed but most
6 importantly- the radiologist is familiar with the disease entity. In this review, my collaborator Dr. Zissin, from Meir Medical Center, Kfar Saba, Israel, and I, review the pathogenesis of infiltrative processes that mimic transitional cell carcinoma of the renal pelvis. We emphasize the importance of clinical information in reaching the correct diagnosis in many of these cases.
I extend my appreciation and gratefulness to all of the authors, who have contributed not only their time and expertise, but also a most valuable collection of images of these diseases, all of which deserve to be titled as 'the great imitator'.
Finally, I would like to dedicate this issue to my mentor and guide Professor Marjorie Hertz and congratulate her on her 88th birthday which she celebrates this June. Prof. Hertz immigrated to Israel from Holland after World War II, and completed her medical studies at the Hebrew University in Jerusalem. Dr. Hertz was a resident in radiology and remained in Sheba Medical Center all her career, becoming the chairman of the department. She has been instrumental in raising generations of radiologists in Israel, many of whom have become prominent leaders in various sub-specialties in the field. I have been particularly fortunate as she painstakingly taught me the art of medical writing and continues to generously and graciously support me with her wisdom and insight over the last 25 years.
Gabriela Gayer, MD Editor
Letter From the Editor: The Great Mimickers in Radiology Gabriela Gayer MD
www.elsevier.com/locate/enganabound
PII: DOI: Reference:
S0887-2171(14)00022-5 10.1053/j.sult.2014.03.001 YSULT579
To appear in: Semin Ultrasound CT MRI
Cite this article as: Gabriela Gayer MD, Letter From the Editor: The Great Mimickers in Radiology, Semin Ultrasound CT MRI , 10.1053/j.sult.2014.03.001 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
1 Letter From the Editor: The Great Mimickers in Radiology Many diseases have been referred to as 'Great Imitator' or 'Great Mimicker'. For the sake of accuracy I looked up the definition in The Dictionary of Modern Medicine (JC. Segen, CRC Press; 1992): "The Great Imitator is a phrase used for medical conditions that feature nonspecific symptoms and may be confused with a number of other diseases. Most great imitators are systemic in nature." The list of diseases referenced is pretty long and includes about 15 entities, among which are quite a few that we, radiologists, rarely encounter since the diseases do not exhibit abnormal imaging findings (e.g. Lyme disease or fibromyalgia). The list of 'Great imitators' for radiologists, is quite different since it is based on imaging findings and not on signs and symptoms. This issue is devoted to such entities, the great imitators in radiology, in order to increase awareness of these conditions and familiarize radiologists with their imaging features. The issue opens with an article on Tuberculosis (TB), a disease that has plagued humankind worldwide for thousands of years. Even now TB still presents an immense health problem in the developing world and remains a healthcare challenge in the developed world. TB results in an estimated 1.7 million deaths each year and the worldwide number of newly diagnosed cases (more than 9 million) is higher than at any other time in history. This review is a collaboration between Drs. Prapruttam and Harisinghani and their colleagues from the Department of Radiology, Massachusetts General Hospital, Boston, and their associates from India. India had the highest total number of TB cases worldwide in 2010, and this collaboration has enabled the inclusion of outstanding illustrations of TB in virtually every organ.
2 Although imaging alone is insufficient in establishing a conclusive diagnosis of TB, familiarity with radiologic manifestations of TB is vital in order for radiologists to alert clinicians to consider tuberculosis in the differential diagnosis. Compared to TB, Sarcoidosis is a much "younger" disease, first described in 1877. In the nearly 150 years since then, many factors and agents have been implicated; however, the exact pathogenesis of the disease remains unknown. Similar to TB, pulmonary involvement is very frequent and many other organ systems (e.g. musculoskeletal, gastrointestinal) may also be involved. The next article spearheaded by Dr. Priya Suresh and her colleagues from the Department of Radiology, Derriford Hospital, in Plymouth, UK, is a casebased systemic approach looking at various systemic manifestations of the disease presenting real clinical encounters using various imaging modalities. Imaging plays a crucial role in supporting the diagnosis, directing treatment and localizing sites for biopsy to confirm the diagnosis. Another systemic disorder that can involve any organ or tissue is Amyloidosis, a rare systemic disease caused by the deposition of abnormal proteins in extracellular soft tissues. It can present with a wide spectrum of symptoms, depending on the organ involved (e.g. chronic cough, dyspnea, splenomegaly). Similarly the imaging findings of Amyloidosis vary according to the infiltrated tissue. The non-specific clinical and imaging characteristics of the disease emphasize the role of the radiologist in raising and including Amyloidosis in the differential diagnosis in the appropriate setting. Drs. Siakallis form Attikon University Hospital in Athens, Greece, and his associates Drs. Tziakouri-Shiakalli and Georgiades from Nicosia,
3 Cyprus, have contributed an exquisitely illustrated review with biopsy-proven Amyloidosis in practically every organ. The abdominal manifestations of IgG(4)-related disease are the subject of the next article. This rapidly emerging disorder is an infiltrative process that can affect various abdominal organs - most commonly the pancreas, but also the bile ducts, gallbladder, kidneys, retroperitoneum and mesentery. The outstanding review and beautiful collection of figures by Dr. Kim and collaborators from Toronto General Hospital, Canada, high lights the challenge for radiologists. Many of the examples include the striking follow-up images, obtained after steroid treatment, showing complete resolution of the lesions. Although the diagnosis is based on a combination of radiologic, serologic, and histologic findings, the radiologist plays an important role in raising the diagnosis of this infiltrative process and thus preventing unnecessary invasive procedures. Unlike the conditions discussed above, extramedullary hematopoiesis (EMH) is not defined as a disease but rather represents a compensatory response to various chronic hematological disorders that result in ineffective hematopoiesis in bone marrow. EMH occurs most often in the spleen and liver but can also involve lymph nodes, pleura, lungs, gastrointestinal tract, breast, skin, brain, kidneys, and adrenal glands. Involved organs appear enlarged on imaging studies (e.g. hepatosplenomegaly). EMH may also present as masses in various sites, most commonly paraspinal masses. These imaging findings may easily be mistaken for a lymphoproliferative process or a neoplasm and therefore tissue biopsy may be required to exclude an alternative diagnosis. Knowledge of the patients’ clinical history is essential for
4 the radiologist to suggest this diagnosis. Drs. Orphanidou-Vlachou, TziakouriShiakalli from Nicosia General Hospital and Dr. Georgiades from the American Medical Center in Nicosia, Cyprus have provided a thorough review with outstanding illustrations exemplifying the many manifestations of EMH. Castleman disease is a rare illness that affects mainly lymph nodes and is also known as giant lymph node hyperplasia and angiofollicular lymph node hyperplasia. This disorder, initially described in 1956, can occur in two different forms - a localized form, referred to as unicentric or a more widespread variety, multicentric Castleman disease. Drs. Bonekamp, Hruban, and Fishman, from The Johns Hopkins University in Baltimore, describe the wide range of symptoms, radiological appearance, treatment and prognosis of both forms of Castleman disease. Like many other disorders included in this issue, the radiological diagnosis of this disease requires familiarity with the spectrum of imaging findings, combined review of these findings with the clinical history of the patient, and a high index of suspicion. Malignant melanoma is an aggressive neoplasm that can involve virtually every organ system. The next article provides a comprehensive review of the various appearances of melanoma involving the chest and abdomen. The typical and atypical CT manifestations of the disease and the similarity of these findings to those of other disease entities grant melanoma the term ' The Great Imitator'. Imaging plays a major role in these patients, initially for the diagnosis, and subsequently for staging, and surveillance. The review by Drs. Chang and Desser from Stanford University School of Medicine, CA and Dr. Menias from Mayo Clinic School of Medicine, Scottsdale, AZ, illustrates the spectrum of imaging findings on US, CT, PET/CT and MRI. It also high
5 lights the role that newer modalities such as contrast-enhanced ultrasound and whole body magnetic resonance imaging may play in the future. The last two reviews do not focus on a single disease but concentrate on a certain body area and explore processes with overlapping imaging findings that affect these sites. The muscular system is comprised of about 700 named muscles that make up roughly half of a person’s body weight. There are several tumors and tumorlike conditions with variable biological behavior that may involve the skeletal musculature. Dr. Surov from Martin-Luther-University Halle-Wittenberg, and Dr. Weber from the University Hospital Heidelberg, Germany, describe the spectrum of lesions that affect the skeletal musculature. Various benign and malignant muscle lesions can manifest with identical radiological patterns. The authors divide these processes into separate categories (discrete intramuscular masses, lesions manifesting as diffuse muscle enlargement, etc) and point to helpful features that serve as guidelines to narrow the differential diagnosis, although biopsy and histologic examination is often necessary. Superb figures, applying all imaging modalities, complement and exemplify a wide range of lesions. The last article sheds light on the many disorders that involve a much more specific site in the body - the renal sinus. Over the last years I have encountered in my clinical practice several different processes affecting this area that were not recognized or not accurately diagnosed, until histology was available and revealed the correct diagnosis. Similar to many other processes covered in this issue, the correct diagnosis may be reached when the clinical information is available, the imaging findings are carefully analyzed but most
6 importantly- the radiologist is familiar with the disease entity. In this review, my collaborator Dr. Zissin, from Meir Medical Center, Kfar Saba, Israel, and I, review the pathogenesis of infiltrative processes that mimic transitional cell carcinoma of the renal pelvis. We emphasize the importance of clinical information in reaching the correct diagnosis in many of these cases.
I extend my appreciation and gratefulness to all of the authors, who have contributed not only their time and expertise, but also a most valuable collection of images of these diseases, all of which deserve to be titled as 'the great imitator'.
Finally, I would like to dedicate this issue to my mentor and guide Professor Marjorie Hertz and congratulate her on her 88th birthday which she celebrates this June. Prof. Hertz immigrated to Israel from Holland after World War II, and completed her medical studies at the Hebrew University in Jerusalem. Dr. Hertz was a resident in radiology and remained in Sheba Medical Center all her career, becoming the chairman of the department. She has been instrumental in raising generations of radiologists in Israel, many of whom have become prominent leaders in various sub-specialties in the field. I have been particularly fortunate as she painstakingly taught me the art of medical writing and continues to generously and graciously support me with her wisdom and insight over the last 25 years.
Gabriela Gayer, MD Editor
