Renal and adrenal tumours in children

Radiomics in differential diagnosis of Wilms tumor and neuroblastoma with adrenal location in children

OBJECTIVES

Machine learning methods can be applied successfully to various medical imaging tasks. Our aim with this study was to build a robust classifier using radiomics and clinical data for preoperative diagnosis of Wilms tumor (WT) or neuroblastoma (NB) in pediatric abdominal CT.

MATERIAL AND METHODS

This is a single-center retrospective study approved by the Institutional Ethical Board. CT scans of consecutive patients diagnosed with WT or NB admitted to our hospital from January 2005 to December 2021 were evaluated. Three distinct datasets based on clinical centers and CT machines were curated. Robust, non-redundant, high variance, and relevant radiomics features were selected using data science methods. Clinically relevant variables were integrated into the final model. Dice score for similarity of tumor ROI, Cohen's kappa for interobserver agreement among observers, and AUC for model selection were used.

RESULTS

A total of 147 patients, including 90 WT (mean age 34.78 SD: 22.06 months; 43 male) and 57 NB (mean age 23.77 SD:22.56 months; 31 male), were analyzed. After binarization at 24 months cut-off, there was no statistically significant difference between the two groups for age (p = .07) and gender (p = .54). CT clinic radiomics combined model achieved an F1 score of 0.94, 0.93 accuracy, and an AUC 0.96.

CONCLUSION

In conclusion, the CT-based clinic-radiologic-radiomics combined model could noninvasively predict WT or NB preoperatively. Notably, that model correctly predicted two patients, which none of the radiologists could correctly predict. This model may serve as a noninvasive preoperative predictor of NB/WT differentiation in CT, which should be further validated in large prospective models.

CLINICAL RELEVANCE STATEMENT

CT-based clinic-radiologic-radiomics combined model could noninvasively predict Wilms tumor or neuroblastoma preoperatively.

KEY POINTS

• CT radiomics features can predict Wilms tumor or neuroblastoma from abdominal CT preoperatively. • Integrating clinic variables may further improve the performance of the model. • The performance of the combined model is equal to or greater than human readers, depending on the lesion size.

Paraneoplastic neurological syndromes of small cell lung cancer

Purpose

This article reviews the relevant literature on paraneoplastic neurological syndromes of small cell lung cancer and discusses the clinical presentation, pathophysiology, and diagnosis of these syndromes. It also includes a summary of the current treatment options for the management of them.

Views

Paraneoplastic syndromes are a group of signs and symptoms that develop due to cancer in a remote site, mainly triggered by an autoantibody produced by the tissues involved or lymphocytes during anti-cancer defense. Among the cancers associated with paraneoplastic syndromes, lung cancers are the most common type, with small cell lung cancer being the most common subtype. The most common antibody associated with paraneoplastic syndromes is anti-Hu. Neurological and neuroendocrine syndromes comprise the majority of small cell lung cancer-related paraneoplastic syndromes. Classical paraneoplastic neurological syndromes include inappropriate antidiuretic hormone secretion, Cushing's syndrome, myasthenia gravis, Lambert-Eaton myasthenic syndrome, limbic encephalitis, paraneoplastic cerebellar degeneration, opsoclonus myoclonus ataxia, sensory neuropathy, and chorea.

Conclusions

Antibodies mediate paraneoplastic syndromes, and antibody detection is a crucial part of diagnosing these entities. Managing the underlying tumor is the best treatment approach for most paraneoplastic syndromes. Therefore, early diagnosis of small cell lung cancer may significantly improve the prognosis of paraneoplastic syndromes associated with it.

The diagnostic value of DMSA scan in differentiating functional pseudo-tumors from malignancies in scarred kidneys: case series and literature review

BACKGROUND

The terms "renal regenerating nodule" and "nodular compensatory hypertrophy" are used in the literature to describe functioning pseudo-tumors (FPT) in the setting of an extensively scarred kidney. FPTs are usually discovered incidentally during routine renal imaging. Differentiating these FPTs from renal neoplasms is critical but can be challenging in the setting of chronic kidney disease (CKD) given the limitations related to using contrast-based imaging.

CASE SUMMARIES

We report a pediatric case series of 5 CKD patients, with history of urinary tract infections, in which tumor-like lesions evolved in scarred kidneys and were incidentally discovered on routine renal imaging. These were diagnosed as FPT by utilizing dimercaptosuccinic acid (DMSA) imaging and showed stable size and appearance upon follow-up with ultrasound and MRI.

CONCLUSION

FPTs can be picked up on routine imaging of pediatric patients with CKD. Although larger cohort studies are needed to confirm these conclusions, our case series supports the evidence that DMSA scan showing uptake at the site of the mass can be a useful tool to suggest the diagnosis of FPTs in children with kidney scarring, and that SPECT DMSA scan adds more precision in picking up and accurately localizing FPTs compared to planar DMSA.

Atypical CT findings of renal neuroblastoma: a case report

BACKGROUND

The neuroblastoma (NB) is a highly malignant tumor of the ectoderm of sympathetic nerve cells and one of the most common malignant tumors in children, which can occur in any part of the sympathetic nerve plexus distribution, however it is less common in the kidney.

CASE DESCRIPTION

Here we present a case of a 4-year-old boy who came to our hospital for medical help because of "abdominal distension for 1 day". Abdominal computed tomography (CT) revealed a huge retroperitoneal soft tissue mass with unclear boundaries with kidneys and adrenal glands, and low-density cystic necrosis areas were seen in the tumor. Contrast-enhanced scan showed that the mass showed mild heterogeneous enhancement. Based on these findings in the patient, he was initially considered to have Wilms tumor, but was finally pathologically confirmed as renal NB. The purpose of this article is to provide the clinicopathological features and CT manifestations of renal NB, and to discuss its differential diagnosis with other renal tumors, in order to better provide clinicians with a better understanding of the rare solid tumor. The renal NB is usually a large lobulated soft tissue mass with unclear boundary and incomplete capsule, which is prone to hemorrhage, necrosis, cystic degeneration and calcification. On CT, the mass is usually isodensity or slightly hypodense, and the cystic degeneration and necrosis area is hypodense, and on contrast-enhanced scan, it can be mildly to significantly enhanced, but the cystic degeneration and necrosis area have no enhancement.

CONCLUSIONS

The CT findings of our case were atypical and overlapped with those of Wilms, so our case suggests that renal NB should be considered as one of the differential diagnoses of Wilms, the most common malignancy of the kidney in children.

Pediatric Abdominal Masses: Imaging Guidelines and Recommendations

Pediatric abdominal masses are commonly encountered in the pediatric population, with a broad differential diagnosis that encompasses benign and malignant entities. The primary role of abdominal imaging in the setting of a suspected pediatric abdominal mass is to establish its presence, as nonneoplastic entities can mimic an abdominal mass, and to identify characteristic imaging features that narrow the differential diagnosis. In the setting of a neoplasm, various imaging modalities play an important role to characterize the mass, stage extent of disease, and assist in presurgical planning. The purpose of this article is to discuss a practical imaging algorithm for suspected pediatric abdominal masses and to describe typical radiological findings of the commonly encountered abdominal masses in neonates and children with emphasis on imaging guidelines and recommendations.

Risk factors for post-nephrectomy hypotension in pediatric patients

BACKGROUND

Although hypotension is a life-threatening complication of nephrectomy in children, risk factors for its development remain unknown. We evaluated the incidence, clinical course, and associated risk factors of pediatric post-nephrectomy hypotension in an observational study.

METHODS

This retrospective observational study included the clinical data of children who underwent nephrectomy in our center between 2002 and 2020. Patients undergoing nephrectomy at kidney transplantation and those who developed hypotension before nephrectomy were excluded.

RESULTS

The study included 55 nephrectomies in 51 patients, including 42 unilateral, 4 two-stage bilateral, and 5 simultaneous bilateral nephrectomies. The diagnoses were isolated Wilms tumor, neuroblastoma, congenital nephrotic syndrome, Denys-Drash syndrome, WAGR (Wilms tumor, aniridia, genitourinary malformations, and mental retardation) syndrome, and autosomal recessive polycystic kidney disease in 24, 10, 9, 6, 1, and 1 patient, respectively. Post-nephrectomy hypotension developed in 11 (20%) patients. Two patients (3.6%) had persistent hypotension; both had their kidneys resected, and one patient (1.8%) died. Male sex, kidney disease, resection of both kidneys, low estimated glomerular filtration rate, increased left ventricular posterior wall thickness in diastole, hypertension before nephrectomy, antihypertensive use, hyperreninemia, and hyperaldosteronism were significantly associated with post-nephrectomy hypotension. Multivariate logistic regression analysis revealed that hypertension before nephrectomy was the only significant risk factor for post-nephrectomy hypotension (P = 0.04).

CONCLUSIONS

Hypertension before nephrectomy is a significant risk factor for pediatric post-nephrectomy hypotension. Life-threatening hypotension, which might occur after bilateral nephrectomy in infants, should be considered, especially in children with higher risks.

Metastatic neuroblastoma masquerading as infantile hemangioma in a 4-month-old child

INTRODUCTION

Diffuse liver lesions in an infant have a differential diagnosis including infantile hemangioma (IH), which is common in the first year of life, and neuroblastoma (NBL) which presents at a median age of 18 months.

RESULTS

We describe the case of a 4-month-old girl with a known superficial/deep IH who presented with new axillary nodules and hepatosplenomegaly, initially suspected to reflect IH but later determined to be widely metastatic NBL.

CONCLUSION

Hepatic IH and metastatic NBL can present similarly. Clinicians must maintain a broad differential when evaluating new findings in a patient with previously diagnosed IH.

Ultrasound of the adrenal gland in children

Ultrasound is the modality of choice in the evaluation of neonates and young children with suspected adrenal lesions including adrenal haemorrhage and congenital adrenal hyperplasia. It is also the initial imaging modality in children presenting with an upper abdominal mass, which may be adrenal in origin. Topic discussion: This paper shows adrenal anatomy and demonstrates how the sonographic features change with age. It reviews the imaging features of congenital adrenal lesions, as well as benign and malignant conditions affecting the adrenal gland in childhood. Discussion and Conclusion: Ultrasound is a useful primary imaging modality in the assessment of the adrenal gland in children. Knowledge of the changes of the adrenal gland with age is important when assessing the adrenal gland. Ultrasound is also useful for assessing abdominal masses. However, it cannot differentiate adrenal masses, therefore correlation with biochemical findings, multimodality imaging, and histology is usually required.

Adrenalectomy for non-neuroblastic pathology in children

BACKGROUND

Adrenalectomy for non-neuroblastic pathologies in children is rare with limited data on outcomes. We reviewed our experience of adrenalectomy in this unique population.

METHODS

Retrospective study of children (age ≤ 18) who underwent adrenalectomy with non-neuroblastic pathology from 1988 to 2018. Clinical and operative details of patients were abstracted. Outcomes included length of stay and 30-day postoperative morbidity.

RESULTS

Forty children underwent 50 adrenalectomies (12 right-sided, 18 left-sided, 10 bilateral). Six patients (15%) presented with an incidental adrenal mass while 4 (10%) had masses found on screening for genetic mutations or prior malignancy. The remaining 30 (75%) presented with symptoms of hormonal excess. Nineteen patients (48%) underwent genetic evaluation and 15 (38%) had genetic predispositions. Diagnoses included 9 patients (23%) with pheochromocytoma, 8 (20%) with adrenocortical adenoma, 8 (20%) with adrenocortical carcinoma, 7 (18%) with adrenal hyperplasia, 2 (5%) with metastasis, and 6 (14%) with additional benign pathologies. Of 50 adrenalectomies, twenty-five (50%) were laparoscopic. Median hospital length of stay was 3 days (range 0-11). Post-operative morbidity rate was 17% with the most severe complication being Clavien-Dindo grade II.

CONCLUSION

Adrenalectomy for non-neuroblastic pathology can be done with low morbidity. Its frequent association with genetic mutations and syndromes requires surgeons to have knowledge of appropriate pre-operative testing and post-operative surveillance.

A Novel MAX Gene Mutation Variant in a Patient With Multiple and "Composite" Neuroendocrine-Neuroblastic Tumors

Introduction: Pheochromocytomas (PCCs), paragangliomas (PGLs), ganglioneuroblastomas (GNBs), and ganglioneuromas (GNs) are neuroendocrine neoplasms (NENs) that were thought to share a common embryologic origin from neural crest cells. However, they rarely occur concurrently and recurrently. We describe the case of a 40-years-old woman with "composite PCC-GN" and multiple NENs and neuroblastic tumors. Case presentation: The patient was first referred to our department at the age of 15 years for paroxysmal hypertension, headache, sweating, and watery diarrhea. Her personal history included the diagnosis of a pelvic GNB with lumbar-aortic lymph node metastases at 11 months. Her family history was positive for cerebral glioblastoma multiforme (father). An abdominal ultrasound showed a right adrenal mass that histologically was a "composite adrenal PCC-GN." The symptoms disappeared after surgery. At the age of 20 years, the symptoms returned: computed tomography (CT) and 131I-metaiodobenzylguanidine (MIBG) scintigraphy showed an inter-aortocaval mass, found histologically to be an inter-aortocaval PGL. Her symptoms reappeared again at 28 years: CT and magnetic resonance imaging revealed four left adrenal gland nodules, found histologically to be multifocal PCCs with some atypia. Genetic screening for VHL, RET, NF1, Tp53, SDHD, SDHB, SDHC, SDHAF2, SDHAF3, SDHA, and TMEM127 was negative. Mutational analysis of the MAX gene revealed the presence of a novel heterozygous variant, c299G>C (p.Arg100Pro, NM_002382.5) that the bioinformatics prediction programs defined as noxious and causative of pathology. Conclusion: This report represents the first description of a co-occurrence of multiple composite PCC-GN and neuroblastic tumors. The long timeline of the presentation of the NENs/neuroblastic tumors from infancy to adulthood requires a lifelong follow-up for this patient. Moreover, the importance of this case lies in the presence of a novel MAX gene variant deleterious, harmful, and causative of pathology, confirmed by Sanger sequencing and never been associated before with multiple composite PCC-GN. The present case underlines the importance of precision medicine and molecular diagnoses for hereditary pheochromocytomas and paragangliomas, suggesting that when they occur in early childhood, it is necessary to perform an extensive genetic investigation and a lifelong follow-up.

[Imaging of abdominal tumors in childhood and adolescence : Part II: relevant intra-abdominal and retroperitoneal tumor entities]

Abdominal and pelvic tumors in children and adolescents can be manifested intra-abdominally and also often in the retroperitoneum. The most important pediatric primary retroperitoneal space-occupying lesions are nephroblastoma (Wilms' tumor) and neuroblastoma, whereby imaging plays a decisive role in the diagnostics and differentiation of the two entities. Benign tumors of the mesentery and gastrointestinal tract occur more frequently in children than malignant lesions. The benign entities include lipoma, polyps and vascular tumors, such as lymphatic malformations. Of the malignant sarcomas, abdominal rhabdomyosarcomas (RMS) occur relatively often in childhood and adolescence. The most frequent pediatric abdominal lymphoma is Burkitt's lymphoma, an aggressive subtype of non-Hodgkin's lymphoma. Relevant tumor entities in childhood are also germ cell tumors, which originate from the genitals (gonadal) or can be extragonadally manifested. The benignancy or malignancy of germ cell tumors ranges from benign teratomas to highly malignant entities, such as yolk sac tumors. The germ cell tumors, just as all pediatric abdominal mass lesions, show a broad spectrum of tumor aggressiveness, malignancy and therefore also prognosis and mortality for the affected children and adolescents.

Staging and following common pediatric malignancies: MRI versus CT versus functional imaging

Most pediatric malignancies require some form of cross-sectional imaging, either for staging or response assessment. The majority of these are solid tumors and this review addresses the role of MRI, as well as other cross-sectional and functional imaging techniques, for evaluating the most common pediatric solid tumors. The primary emphasis is on neuroblastoma, hepatoblastoma and Wilms tumor, three of the most common non-central-nervous-system (CNS) pediatric solid tumors encountered in young children. The initial focus will be a review of the imaging techniques and approaches used for diagnosis, staging and early post-treatment response assessment, followed by a discussion of the role surveillance imaging plays in pediatric oncology and a brief review of other emerging imaging techniques. The lessons learned here can be applied to most other pediatric tumors, including rhabdomyosarcoma, Ewing sarcoma and osteosarcoma, as well as germ cell tumors, neurofibromatosis and other rare tumors. Although lymphoma, in particular Hodgkin lymphoma, represents one of the more common pediatric malignancies, this is not discussed in detail here. Rather, many of the lessons that we have learned from lymphoma, specifically with regard to how we integrate both anatomical imaging and functional imaging techniques, is applied to the discussion of the other pediatric solid tumors.

Imaging of Nonmalignant Adrenal Lesions in Children

The adrenal glands in children can be affected by a variety of benign lesions. The diagnosis of adrenal lesions can be challenging, but assessment of morphologic changes in correlation with the clinical presentation can lead to an accurate diagnosis. These lesions can be classified by their cause: congenital (eg, discoid adrenal gland, horseshoe adrenal gland, and epithelial cysts), vascular and/or traumatic (eg, adrenal hemorrhage), infectious (eg, granulomatous diseases), enzyme deficiency disorders (eg, congenital adrenal hyperplasia [CAH] and Wolman disease), benign neoplasms (eg, pheochromocytomas, ganglioneuromas, adrenal adenomas, and myelolipomas), and adrenal mass mimics (eg, extralobar sequestration and extramedullary hematopoiesis). Multimodality cross-sectional imaging helps to define the origin, extent, and relationship of these lesions to adjacent structures, as well as to guide treatment management. The anatomic and functional imaging modalities used to evaluate pediatric adrenal lesions include ultrasonography, computed tomography (CT), magnetic resonance imaging, and iodine 123 metaiodobenzylguanidine scintigraphy. Identifying the imaging features of nonmalignant adrenal lesions is helpful to distinguish these lesions from malignant adrenal neoplasms. Identifying characteristic imaging findings (eg, enlarged adrenal glands, with cerebriform surface, and stippled echogenicity in CAH; a T2-hyperintense mass with avid contrast enhancement in pheochromocytoma; low CT attenuation [<10 HU] and signal intensity drop on opposed-phase chemical shift images in adenoma; and enhancing suprarenal mass supplied by a systemic feeding artery in extralobar sequestration) can aid in making the correct diagnosis. In addition, clinical features (eg, ambiguous genitalia in CAH and hypertension in pheochromocytoma) can also guide the radiologist toward the correct diagnosis. ^©RSNA, 2017.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 1. The 1st Decade: From the Radiologic Pathology Archives

Wilms tumor is the second most common pediatric solid tumor and by far the most common renal tumor of infants and young children. As most tumors are large at presentation and are treated with nephrectomy, the role of imaging is primarily in preoperative planning and evaluation for metastatic disease. However, with treatment protocols increasingly involving use of preoperative (neoadjuvant) chemotherapy (the standard in Europe) and consideration of nephron-sparing surgery, the role of imaging is evolving to include providing initial disease staging information and a presumptive diagnosis to guide therapy. Differential diagnostic considerations include lesions that are clinically benign and others that require more intensive therapy than is used to treat Wilms tumor. In part 1 of this article, the unique histologic spectrum of renal neoplasms of infants and young children is reviewed with emphasis on radiologic-pathologic correlation. Part 2 will focus on renal tumors of older children and adolescents.

Adrenal Mass: Unusual Presentation and Outcome

Aim:

Adrenal mass may be functioning or nonfunctioning with varied clinical presentations. This study aimed to report the nature and management of uncommon adrenal mass and to review literature.

Materials and Methods:

This was an retrospective observational analysis of children with uncommon adrenal mass admitted during 2009–2015. Clinical features, investigations, and management of patients were analyzed.

Results:

Among six, two each were adolescent and neonate, and one each was young infant and prenatal. Clinical presentation was variable; hypertensive retinopathy,[1] virilization[1] and bleeding diathesis,[1] antenatal suprarenal mass,[1] prenatal adrenal angiolipoma,[1] and spontaneous resolution of Stage III suprarenal mass.[1] Ultrasound and contrast-enhanced computed tomography revealed well-defined, heterogeneous adrenal mass. Size varied from 2 to 15 cm. Urinary metanephrine and serum testosterone were raised in adolescent hypertensive boys and virilized girls, respectively. Laparoscopy-assisted adrenalectomy was done in two and other four were managed conservatively. Histopathology of tumor revealed pheochromocytoma and borderline oncocytoma. Spontaneous resolution of adrenal mass had varied etiology; adrenal hemorrhagic lesion,[1] simple cyst,[1] neuroblastoma.[1] Follow-up varied from 3 months to 2 years. All patients were asymptomatic on last follow-up.

Conclusion:

Close clinical follow-up, contrast-enhanced tomography, and limited/specific endocrine work-up have definite role in the management of uncommon adrenal mass.

Carboplatin-based Nanomedicine to Enhance the Anticancer Effect in SK-NEP-1 WilmsꞌTumor Cells

Wilms tumor (WT) is the most common pediatric malignant primary renal tumor. Carboplatin (CRB), a platinum compound is widely used in the treatment of multiple cancers including ovarian, lung, head and neck, and wilm's tumor. However, lower uptake of CRB in cancer cells and toxicity concerns in healthy cells often limited its clinical outcome. The aim of this study was to investigate the antitumor effect of CRB on SK-NEP-1 wilm's cancer cells. Earlier, CRB was formulated in nanoparticulate formulations and characterized its biophysical parameters. SK-NEP-1 cell growth in vitro was assessed by MTT. Then, apoptosis potential was investigated by TUNEL, Hoechst, and colony formation assay. CRB treatment resulted in inhibition of cell proliferation of SK-NEP-1cells in a dose-dependent manner. TUNEL, Hoechst, and colony formation assay demonstrated that CRB was more effective in killing wilm's cancer cell when encapsulated in nanoparticle formulations. Overall, the present study demonstrates that CRB treatment resulted in marked inhibition of cell proliferation and cell apoptosis. These results may pave way for the effective treatment of wilm's tumor in clinical models.

A single enhanced phase is sufficient for the initial computed tomography evaluation of retroperitoneal tumors in children

PURPOSE

The goal of this study was to evaluate the incremental value of unenhanced phase in the initial evaluation of retroperitoneal tumors in children by comparison with an enhanced phase alone using computed tomography (CT).

MATERIALS AND METHODS

A total of 53 patients (26 girls, 27 boys) with a total of 53 tumors who had CT examination of the abdomen and pelvis for the initial assessment of retroperitoneal tumor were retrospectively included. All CT examinations were obtained with an unenhanced set of CT images and a set of CT images obtained after intravenous administration of iodinated contrast material. One junior and one senior radiologist independently evaluated the two sets in two separate reading sessions. CT images were analyzed for tumor calcifications, tumor location, vascular encasement, local invasion and tumor content.

RESULTS

Calcifications were present in 24/53 tumors (45%). On the enhanced set, the senior radiologist was able to detect calcifications in 22/24 tumors (92%) and the junior radiologist in 20/24 tumors (83%), yielding sensitivities of 92% and 83%, and specificities of 96.5% and 100%, respectively. Inter-observer agreement was excellent (Kappa=0.89). Tumor location was correctly determined by the senior radiologist in 53/53 tumors (100%) and 37/53 tumors (70%) by the junior radiologist. Using the unenhanced set, the senior radiologist was able to assess vascular encasement in 26/53 tumors (49%) against 21/53 (39%) for the junior radiologist. For tumor content, agreement between the enhanced and combined unenhanced and enhanced CT was 77% for both radiologists.

CONCLUSION

Enhanced CT performs as well as unenhanced CT for evidencing calcifications and is therefore sufficient for the initial assessment of retroperitoneal tumor in children.

Syndrome-Associated Tumors by Organ System

Certain tumors suggest the possibility of a patient harboring a genetic syndrome, particularly in children. Syndrome-associated tumors of the gastrointestinal tract, genitourinary tract, gynecologic tract, heart, lungs, brain, eye, endocrine organs, and hematopoietic system will be briefly discussed.

Childhood neuroblastoma masquerading as pheochromocytoma: case report

Neuroblastoma is the most common extracranial solid tumor in children. Mild hypertension is a frequent symptom, presumably an effect of catecholamines that tumors release. Reported herein is the rare occurrence of severe hypertension and subsequent heart failure attributable to adrenal gland neuroblastoma. A 3-year-old boy presented with anterior chest wall protrusion. Physical examination revealed severe hypertension, and left-sided cardiac failure was evident by echocardiography. Catecholamine metabolite (norepinephrine) levels were increased in serum (>2,000 pg/mL) and in urine (1,350.5 µg/day). Abdominal computed tomography scan showed a 7 cm solid mass arising from right adrenal gland. Oral phenoxybenzamine was given for hemodynamic stabilization, and right adrenalectomy was performed to remove an apparent pheochromocytoma. Ultimately, the pathologic diagnosis was ganglioneuroblastoma. Both hypertension and cardiac failure resolved postoperatively.

Malignant renal tumors in children

Renal malignancies are common in children. While the majority of malignant renal masses are secondary to Wilms tumor, it can be challenging to distinguish from more aggressive renal masses. For suspicious renal lesions, it is crucial to ensure prompt diagnosis in order to select the appropriate surgical procedure and treatment. This review article will discuss the common differential diagnosis that can be encountered when evaluating a suspicious renal mass in the pediatric population. This includes clear cell sarcoma of the kidney, malignant rhabdoid tumor, renal medullary carcinoma and lymphoma.

Neuroblastoma and nephroblastoma: a radiological review

Neuroblastoma (NBL) is the most common extra-cranial tumour in childhood. It can present as an abdominal mass, but is usually metastatic at diagnosis so the symptomatology can be varied. Nephroblastoma, also more commonly known as a Wilms tumour, is the commonest renal tumour in childhood and more typically presents as abdominal pathology with few constitutional symptoms, although rarely haematuria can be a presenting feature. The pathophysiology and clinical aspects of both tumours including associated risk factors and pathologies are discussed. Oncogenetics and chromosomal abnormalities are increasingly recognised as important prognostic indicators and their impact on initial management is considered. Imaging plays a pivotal role in terms of diagnosis and recent imaging advances mean that radiology has an increasingly crucial role in the management pathway. The use of image defined risk factors in neuroblastoma has begun to dramatically change how this tumour is characterised pre-operatively. The National Wilms Tumour Study Group have comprehensively staged Wilms tumours and this is reviewed as it impacts significantly on management. The use of contrast-enhanced MRI and diffusion-weighted sequences have further served to augment the information available to the clinical team during initial assessment of both neuroblastomas and Wilms tumours. The differences in management strategies are outlined. This paper therefore aims to provide a comprehensive update on these two common paediatric tumours with a particular emphasis on the current crucial role played by imaging.

Epidemiologic survey of infantile cancer in Iran based on the data of the largest pediatric cancer referral center (Ali- Asghar Children Hospital), 1996-2005

BACKGROUND

Cancer in infants younger than one year of age represents a unique problem with distinct epidemiological, clinical and genetic characteristics compared with older age groups. No report is yet available from Iran regarding epidemiological and survival rate of cancers diagnosed in this age group.

MATERIALS AND METHODS

The population under study comprised of patients which were diagnosed and admitted to Ali-Asghar hospital between years 1996-2005. In total, 287 infants were included in the retrospective descriptive survey. Patient files were evaluated for age of patient at the time of diagnosis, sex, geographical residence, consanguinity of parents, histological diagnosis, site of cancer involvement, type of therapy, date of last follow-up and cause of death (if applicable).

RESULTS

The average age at the time of diagnosis was 7.2 months old. The most frequent malignancy was retinoblastoma (44%), followed by leukemia (19%) and neuroblastoma (10%), with five-year overall survival rates of 77.7%, 41% and 90%, respectively Parents of 40 infants (13.9%) had consanguinity relationships.

CONCLUSIONS

Although we cannot make any conclusions regarding the incidence of infant cancer subtypes based on this study, survival rates for major types were similar to the developed countries, which signifies strict adherence to standards of care in Ali-Asghar hospital, the main infant cancer care centre in Iran. A Childhood Cancer Registry with high-resolution data collection and also advanced genetic testing is advocated for in-depth analysis of variation in incidence and survival.

Treatment of Wilms tumor using carboplatin compared to therapy without carboplatin

BACKGROUND

Wilms tumor (WT) is the most common pediatric malignant primary renal tumor. One of the main drugs used in treatment is actinomycin-D. This was not readily available in Turkey at one time. Carboplatin was used in the primary treatment of WT in order to prevent delays in treatment. The aim of this study is to present the results of patients with WT receiving carboplatin or actinomycin-D therapy.

PROCEDURE

Forty-eight consecutive patients with WT treated between July 2005 and December 2011 were included in this retrospective study. The patients were treated according to Turkish Pediatric Oncology Group guidelines. Nineteen patients were treated with actinomycin-D and 29 with carboplatin (500 mg/m(2) /dose). The two groups were then compared in terms of 2- and 4-year overall survival (OS), event-free survival (EFS) and disease-free survival (DFS).

RESULTS

Two- and four-year OS rates in the carboplatin group were 90.0% and 90.0%, compared to 100.0% and 88.0%, respectively, in the non-carboplatin group. Two- and four-year EFS levels in the carboplatin group were 92.0% and 88.0%, respectively, compared to 82.0% and 76.0% in the non-carboplatin group. Two-and four-year DFS levels in the carboplatin group were 92.0% and 86.0%, respectively, compared to 77.0% and 77.0% in the non-carboplatin group.

CONCLUSIONS

The findings show that the carboplatin can be used as an alternative drug in the primary treatment of WT in the event that actinomycin-D is unavailable or not tolerated.

Pheochromocytoma management, outcomes and the role of cortical preservation

OBJECTIVES

To evaluate the management and outcome of children with pheochromocytoma and determine the role of cortex preservation in cases of bilateral disease.

METHODS

Retrospective review of children, below 12 y of age, with pheochromocytoma managed between November 2003 and December 2012 was done.

RESULTS

Twelve patients, nine boys and three girls with median age 9 y were enrolled. Eleven (92 %) had adrenal tumors and in one it was extra-adrenal. Five (42 %) had bilateral disease. Ten presented with hypertension, one with headache and one with abdominal pain and fever. All were stabilized pre-operatively with alpha and beta blockers and volume expansion. Six children with unilateral disease underwent total adrenalectomy. Out of five with bilateral disease, one child underwent bilateral total adrenalectomy and was later started on hormone replacement. Remaining four underwent total adrenalectomy on one side and partial on the other side. Post-operatively all became symptom free and normotensive and were off medications within 1 mo. Two children developed recurrence 1 mo post-operatively, one with an initial unilateral pheochromocytoma and one with paraganglionoma. At the last follow up, 10 out of 12(83 %) were disease free while two with recurrence are still awaiting surgery.

CONCLUSIONS

Surgical resection of pheochromocytoma is effective treatment to achieve cure and prolong survival. Cortex preservation should be done in bilateral disease as risk of recurrence in such cases seems to be of lesser significance as compared to the morbidity and mortality of adrenal insufficiency and consequent lifelong hormone replacement.

Diagnostic radiology in paediatric palliative care

Palliative care is an expanding specialty within paediatrics, which has attracted little attention in the paediatric radiological literature. Paediatric patients under a palliative care team will have numerous radiological tests which we traditionally categorise under organ systems rather than under the umbrella of palliative medicine. The prevalence of children with life-limiting illness is significant. It has been estimated to be one per thousand, and this may be an underestimate. In this review, we will focus on our experience at one institution, where radiology has proven to be an invaluable partner to palliative care. We will discuss examples of conditions commonly referred to our palliative care team and delineate the crucial role of diagnostic radiology in determining treatment options.

Multi-modality organ-based approach to expected imaging findings, complications and recurrent tumour in the genitourinary tract after radiotherapy

PURPOSE

Radiotherapy (RT) is an integral component in the management of many abdominal and pelvic malignancies. Imaging follow-up in patients who have received RT is performed to assess for treatment response, evaluate for tumour recurrence and to diagnose complications related to treatment. The purpose of this pictorial review is to depict the expected imaging findings and potential complications following RT in the genitourinary (GU) tract using an organ-based approach and to review the diagnosis of locally recurrent tumour in the GU tract following RT.

CONCLUSIONS

Some GU malignancies, namely cervical and prostatic carcinoma, can be treated with radical RT with intent to cure. More frequently, the GU tract is indirectly treated as a result of RT to adjacent cancers. Expected imaging findings, RT-related complications and the diagnosis of recurrent tumour following RT in the GU tract often necessitate a multi-modality imaging approach, the incorporation of functional imaging techniques and an organ-based approach for diagnosis.

Imaging spectrum of primary malignant renal neoplasms in children

Wilms' tumor (WT) is the most common abdominal tumor in children. Many pediatric renal tumors in the past were categorized as WT; however, in recent years, several specific renal tumors have been recognized as distinct pathological entities. The age and clinical presentation of the child and distinctive imaging features may help in reaching a specific diagnosis in most cases. This is important as it has implications on the pre-operative diagnostic work-up and prognosis of the child. However, it is often not possible to differentiate one from the other pediatric renal tumor on the basis of imaging alone, and the final diagnosis is often made at histological examination of the surgical specimen. This article reviews the imaging features of primary malignant renal neoplasms in children along with their clinical presentation and pathological features.

KCNQ1OT1 hypomethylation: a novel disguised genetic predisposition in sporadic pediatric adrenocortical tumors?

Pediatric adrenal tumors, other than neuroblastoma, are rare and can be associated with a genetic predisposition. In this report we describe two patients with an isolated and apparently sporadic adrenocortical tumor; one girl with a carcinoma, the other girl with an adenoma. In both patients genetic screening revealed hypomethylation of the KCNQ1OT1 gene, well-known for its association with the Beckwith-Wiedemann syndrome. This represents a likely novel genetic predisposition in patients with adrenocortical tumors without clear phenotypic features of the Beckwith-Wiedemann syndrome.

Pediatric primary and metastatic neuroblastoma: MRI findings: pictorial review

Magnetic resonance imaging (MRI) has become one of the most valuable modalities for initial and follow-up imaging of suspected or known neuroblastoma (NBL) owing to its excellent inherent contrast, lack of ionizing radiation and multiplanar imaging capability. Importantly, NBL has a variable appearance on different imaging modalities, and this is particularly pertinent to MRI. MRI is a cornerstone for management of NBL, providing essential information at initial presentation regarding diagnosis, staging, resectability and relation to vital structures. It can also define the extent of residual disease after surgical resection or assess the efficacy of treatment. Follow-up MRI is frequently performed to ensure sustained complete remission or to monitor known residual disease. This pictorial review article aims to provide the reader with a concise, yet comprehensive, collection of MR images of primary and metastatic NBL lesions with relevant correlation with other imaging modalities.

CT and MRI appearances and radiologic staging of pediatric renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is an uncommon but noteworthy primary pediatric renal malignancy. There is a paucity of published data regarding the CT/MRI appearances and accuracy of pretreatment radiologic staging of this form of cancer in children.

OBJECTIVE

To review the various CT/MRI appearances of pediatric RCC and assess the accuracy of pretreatment radiologic staging using these imaging modalities.

MATERIALS AND METHODS

Institutional Departments of Pathology and Radiology records were searched from 1995 through 2010 for children (younger than 18 years of age) with RCC. Available pretreatment contrast-enhanced abdominopelvic CT and MRI examinations were reviewed by two radiologists. Pertinent imaging findings were documented by consensus, and correlation was made between radiologic and surgicopathological TNM staging.

RESULTS

Pretreatment imaging studies from 10 RCCs in nine children (four girls and five boys; mean age 12.9 years) were reviewed. The mean size of the primary tumor was 6.2 cm (range, 1.5-12.6 cm). Ninety percent of RCCs demonstrated heterogeneous postcontrast enhancement. Fifty percent of masses had associated hemorrhage, while 40% contained internal calcification. Regarding TNM staging, N staging was correct for 10 of 10 tumors, while M staging was correct for 10 of 10 tumors. Imaging correctly staged only 4 of 10 tumors with respect to T stage. Radiologic and surgicopathological overall staging were concordant for 8 of 10 tumors.

CONCLUSION

Pediatric RCCs typically present as large, heterogeneous masses, and they commonly hemorrhage and contain internal calcification. Radiologic and surgicopathological overall TNM staging are frequently concordant, although radiologic T staging is often incorrect.

Atypical imaging features of adrenal gland lesions in children - report of three cases and review of literature

BACKGROUND

The differential diagnosis of adrenal pathology depends on the child's age and imaging findings.

CASE REPORT

Three children without clinical symptoms of neoplasm, with an adrenal lesion discovered on diagnostic ultrasound imaging. Laboratory tests for neoplasm were negative. The final diagnosis was based on histopathological examinations after surgical resection.

CONCLUSIONS

1. The value of diagnostic imaging and laboratory tests in differential diagnosis of adrenal gland lesions is limited. 2. Malignant tumors of adrenal glands should be taken into account in children. 3. Surgical resection should be considered in diagnostic algorithm of adrenal gland masses. 4. The final diagnosis is always based on histopathological examination.

Neuroblastoma

Neuroblastoma is a common malignancy of infancy and early childhood. The difference in the outcomes for patients with these neoplasms is striking. Infants younger than one year have a good prognosis, even in the presence of metastatic disease, whereas older patients with metastatic disease fare poorly even when treated with aggressive therapy. The noninvasive nature of diagnostic sonography has allowed it to play a major role in the early detection and treatment of neuroblastoma. This early sonographic detection, in conjunction with early postnatal surgical intervention, has greatly improved the prognosis of infants born with neuroblastoma.

Adrenal masses in children

Adrenal tumors include those of neural and cortical origin. Although most neuroblastomas present as abdominal masses, pheochromocytomas and cortical tumors usually present with endocrine dysfunction. Although imaging may not be able to differentiate benign lesions from malignant tumors, or whether they arise in the adrenal medulla or cortex, imaging is useful in determining the extent of the lesion and its relation to surrounding anatomic structures, particularly to vessels. Regardless of what imaging modality is used, meticulous attention to technique is required.

Polycythemia and adrenal cortex tumor in children: a case report and literature review

Brazil has the world's highest incidence of adrenal cortex tumor in childhood, mainly in Parana and Sao Paulo states. The diagnosis in children is done by the signs and symptoms secondary to the production of adrenal cortex hormones. The occurrence of polycythemia in patients with adrenal cancer is very rare, especially in children. The authors describe a case of adrenal cortex tumor in a child diagnosed during investigation of polycythemia. In the case described, the polycythemia was justified by increased production of erythropoietin.

Mediastinal involvement in lymphangiomatosis: a previously unreported MRI sign

BACKGROUND

Multifocal lymphangiomatosis is a rare systemic disorder affecting children. Due to its rarity and wide spectrum of clinical, histological and imaging features, establishing the diagnosis of multifocal lymphangiomatosis can be challenging.

OBJECTIVES

The purpose of this study was to describe a new imaging sign in this disorder: paraspinal soft tissue and signal abnormality at MRI.

MATERIALS AND METHODS

We retrospectively reviewed the imaging, clinical and histopathological findings in a cohort of eight children with thoracic involvement from this condition.

RESULTS

Evidence of paraspinal chest disease was identified at MRI and CT in all eight of these children. The changes comprise heterogeneous intermediate-to-high signal parallel to the thoracic vertebrae on T2-weighted sequences at MRI, with abnormal paraspinal soft tissue at CT and plain radiography.

CONCLUSION

Multifocal lymphangiomatosis is a rare disorder with a broad range of clinicopathological and imaging features. MRI allows complete evaluation of disease extent without the use of ionising radiation and has allowed us to describe a previously unreported imaging sign in this disorder, namely, heterogeneous hyperintense signal in abnormal paraspinal tissue on T2-weighted images.

Guidelines for imaging and staging of neuroblastic tumors: consensus report from the International Neuroblastoma Risk Group Project

Neuroblastoma is an enigmatic disease entity; some tumors disappear spontaneously without any therapy, while others progress with a fatal outcome despite the implementation of maximal modern therapy. However, strong prognostic factors can accurately predict whether children have "good" or "bad" disease at diagnosis, and the clinical stage is currently the most significant and clinically relevant prognostic factor. Therefore, for an individual patient, proper staging is of paramount importance for risk assessment and selection of optimal treatment. In 2009, the International Neuroblastoma Risk Group (INRG) Project proposed a new staging system designed for tumor staging before any treatment, including surgery. Compared with the focus of the International Neuroblastoma Staging System, which is currently the most used, the focus has now shifted from surgicopathologic findings to imaging findings. The new INRG Staging System includes two stages of localized disease, which are dependent on whether image-defined risk factors (IDRFs) are or are not present. IDRFs are features detected with imaging at the time of diagnosis. The present consensus report was written by the INRG Imaging Committee to optimize imaging and staging and reduce interobserver variability. The rationales for using imaging methods (ultrasonography, magnetic resonance imaging, computed tomography, and scintigraphy), as well as technical guidelines, are described. Definitions of the terms recommended for assessing IDRFs are provided with examples. It is anticipated that the use of standardized nomenclature will contribute substantially to more uniform staging and thereby facilitate comparisons of clinical trials conducted in different parts of the world.

Malignant tumours of the kidney: imaging strategy

Primitive malignant renal tumours comprise 6% of all childhood cancers. Wilms tumour (WT) or nephroblastoma is the most frequent type accounting for more than 90%. Imaging alone cannot differentiate between these tumours with certainty but it plays an important role in screening, diagnostic workup, assessment of therapy response, preoperative evaluation and follow-up. The outcome of WT after therapy is excellent with an overall survival around 90%. In tumours such as those where the outcome is extremely good, focus can be shifted to a risk-based stratification to maintain excellent outcome in children with low risk tumours while improving quality of life and decreasing toxicity and costs. This review will discuss the imaging issues for WT from the European perspective and briefly discuss the characteristics of other malignant renal tumours occurring in children and new imaging techniques with potential in this matter.