CASE REPORT
Rhabdoid Tumor: An Aggressive Renal Medullary Tumor of Childhood Shannon G. Farmakis, MD* and Marilyn J. Siegel, MD†
Abstract: We present a case of a renal rhabdoid tumor in a 2-month-old girl. Rhabdoid tumors are rare primary renal tumors in children, but they have characteristic features—medullary sinus invasion and subcapsular fluid collections—which enable a specific diagnosis. The classic imaging characteristics of this tumor compared to other more common primary pediatric renal tumors will be reviewed. Key Words: rhabdoid tumor, renal, pediatric, medullary (J Comput Assist Tomogr 2015;39: 44–46)
R
habdoid tumors (RTs) account for approximately 0.9% to 2% of renal tumors in children.1 The entity was first described in 1978 as a sarcomatoid variant of Wilms tumor but was quickly recognized to represent a unique entity.2 Distinguishing these tumors from other primary renal tumors in children is important as the treatment and prognosis are different.
CASE REPORT A previously healthy 2-month-old girl presented to an outside emergency department with a 1-week history of increased fussiness, decreased appetite, emesis, and increasing abdominal distension. Pertinent laboratory values included decreased hemoglobin and hematocrit as well as hematuria. Ionized calcium levels were eventually obtained which were mildly elevated at 5.32 mg/dL (reference range, 3.9–5.2 mg/dL). An ultrasound was performed which revealed a large heterogeneous mass arising from the right kidney with large areas of peripheral necrosis (Fig. 1). After transfer to our institution, a computed tomography of abdomen/pelvis was obtained which showed a large mass arising from the right kidney and occupying most of the right hemiabdomen (Fig. 2). Large peripheral subcapsular fluid collections were seen within the mass. The mass compressed the inferior vena cava, and multiple collateral vessels were seen, including a dilated azygos vein and paravertebral venous plexuses. There was no evidence of metastatic disease to the chest. The patient underwent a radical right nephrectomy with regional lymphadenectomy (Fig. 3). Histologic findings revealed a malignant RT that involved the renal hilum and sinuses; however, there was no evidence of vascular invasion or capsular extension. INI-1 immunostaining confirmed loss of the INI-1 gene. Bone scintigraphy and magnetic resonance imaging (MRI) of the brain did not show evidence of metastatic disease. The patient was subsequently treated with vincristine, cisplatin, doxorubicin, and cyclophosphamide. Serial imaging scans during an 8-month period From the *Department of Radiology, St Louis University School of Medicine; and †Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO. Received for publication October 27, 2014; accepted October 31, 2014. Reprints: Shannon G. Farmakis, MD, Department of Radiology, St Louis University School of Medicine, 3635 Vista Av at Grand Blvd, St Louis, MO (e‐mail: [email protected]). An expanded discussion of this “Case of the Quarter” can be found at the SCBTMR Web site: scbtmr.dnnstaging.com. The authors declare no conflict of interest. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
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showed no evidence of local recurrence. However, a surveillance brain MRI showed a nonoperable pineal mass, consistent with a new primary intracranial neoplasm.
DISCUSSION Rhabdoid tumor of the kidney is an aggressive embryonal tumor, which arises from primitive cells in the renal medulla and frequently involves the hilum and collecting system.3–5 It accounts for less than 2% of childhood renal tumors and is associated with loss or inactivation of the SMARCB1 gene, also referred to as the BAF47, SNF5, or INI1 tumor suppressor gene, on chromosome 22q.1,6 This mutation can be inherited or arise somatically. Approximately 10% to 15% of affected children have primary brain tumors, including RT, ependymoma, astrocytoma, and primitive neuroectodermal tumors.1,2,7 The brain tumor is usually near the midline and in the posterior fossa. Primary RTs of the brain are also referred to as atypical rhabdoid/teratoid tumors.1 The median age of patients with renal RT is 18 months with a mean age of 11 months.8 It affects boys slightly more commonly than girls (1.5:1).9 The common symptoms at presentation include gross hematuria, hypercalcemia related to elevated serum parathormone levels, abdominal distension or pain, fussiness, and fever.7,9–12 Staging of renal RTs is based on the Children's Oncology Group staging of Wilms tumors after surgical resection of the mass. More than two thirds of patients with RT have advanced disease at presentation, usually with metastases to the lungs and brain.8,9 Ten to 15% of patients will have intracranial lesions.8 Prognosis varies with patient age. Overall survival is poor in young patients with infants younger than 6 months having a survival rate of 9% compared to those older than 2 years having a 41% overall survival.8 Most patients present with advanced disease (stage III 55% and stage IV 24%) compared to stage I and II disease (3% and 18%, respectively).9 Radical surgical resection with lymph node dissection is the treatment of choice followed by chemotherapy.10 No specific combination of chemotherapeutic agents has proven to be best in treating this tumor. Various combinations have been used including ifosfamide, carboplatin, and etoposide, etoposide and ifosfamide, and cisplatin and etoposide.8 Although RTs have been reported to involve both kidneys, most cases are solitary (96%).2,9 On computed tomography, RT appears as a large, heterogeneous, infiltrative intrarenal mass with indistinct margins and infiltration of the renal hilum. Additional findings include renal capsular thickening, a peripheral crescentic subcapsular fluid collection representing a tumoral necrosis and/ or hemorrhage, and calcifications.2–5,7 The peripheral collection is a characteristic occurring in approximately 70% of patients with RT compared to only 12% in other pediatric renal tumors, such as Wilms tumor, mesoblastic nephroma, clear-cell sarcoma, and rarely renal cell carcinoma and undifferentiated sarcoma.7 The tumor may extend into the renal vein or inferior vena cava.11 The increased incidence of second primary tumors in the brain in these patients makes an imaging diagnosis important, as MRIs of the brain and
J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Rhabdoid Tumor
FIGURE 1. A, Longitudinal sonogram of the right kidney demonstrates a large heterogeneous, echogenic renal mass (arrowheads) replacing most of the kidney. Also noted is a large peripheral subcapsular fluid collection with internal septations (arrows). This appearance is characteristic of renal RT. B, Transverse image of the right kidney with color Doppler demonstrates minimal vascularity in the solid portion of the mass. Figure 1 can be viewed online in color at www.jcat.org.
FIGURE 2. A and B, Axial images and (C) coronal reconstruction of the abdomen and pelvis demonstrate a large infiltrative mass (M) arising from the right kidney and infiltrating the central renal sinus and a large peripheral subcapsular fluid collection (arrows). The tumor displaces bowel to the left. Open arrow indicates residual enhancing renal parenchyma.
central nervous system are not routinely obtained in the metastatic workup of most pediatric renal masses but should be performed in children with renal RTs. The differential diagnostic considerations of RT include Wilms tumor, renal cell carcinoma, and clear-cell sarcoma. Wilms tumor is the most common renal tumor in childhood, accounting for more than 85% of renal masses. Renal cell carcinoma is very rare in childhood. However, it can be seen in older children (typically second decade of life). Unlike RT, Wilms tumor and renal cell carcinoma arise in the renal cortex. Both tend to be well circumscribed, large, heterogeneous masses, and they distort rather than infiltrate the adjacent parenchyma.3,4 Although imaging findings are similar, the patient age is helpful in separating these 2 entities. Clear-cell sarcoma is another extremely rare pediatric tumor. It most often affects children age 1 to 4 years. Like RT, it arises in the renal medulla and infiltrates the kidney, but it typically contains large cystic areas, and it is the only pediatric renal malignancy that commonly metastasizes to the bone.3–5
CONCLUSIONS In conclusion, RT is a rare and aggressive primary pediatric renal tumor that arises from the renal medulla, invades the renal hilum
FIGURE 3. Gross specimen of resected tumor cut in half shows the solid component of the tumor and large subcapsular fluid collections (arrows) representing areas of hemorrhagic necrosis. (Photograph courtesy of Louis P. Dehner, MD.) Figure 3 can be viewed online in color at www.jcat.org.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.jcat.org
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J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Farmakis and Siegel
and collecting system, and classically appears as an infiltrative mass with a peripheral subcapsular fluid collection representing hemorrhagic necrosis. It needs to be included in the differential diagnostic considerations of renal masses in a young pediatric population as an imaging-based diagnosis can direct the clinicians to do a more appropriate metastatic workup for this tumor compared to that performed for other pediatric renal tumors. REFERENCES 1. Heck JE, Lombardi CA, Cockburn M, et al. Epidemiology of rhabdoid tumors of early childhood. Pediatr Blood Cancer. 2013;60:77–81. 2. Chang CJ, Yeh ML, Chen CC. Rhabdoid tumor of the kidney with spontaneous rupture: case report and review of literature. Pediatr Surg Int. 2008;24:451–453. 3. Lowe LH, Isuani BH, Heller RM, et al. Pediatric renal masses: Wilms tumor and beyond. Radiographics. 2000;20:1585–1603.
6. Dome JS, Fernandez CV, Mullen EA. Children's oncology group’s 2013 blueprint for research: renal tumors. Pediatr Blood Cancer. 2013;60: 994–1000. 7. Agrons GA, Kingsman KD, Wagner BJ, et al. Rhabdoid tumor of the kidney in children: a comparative study of 21 cases. Am J Roentgenol. 1997;168:447–451. 8. United States. National Cancer Institute (2014) Wilms tumor and other childhood kidney tumors treatment (PDQ®). http://www.cancer.gov/ cancertopics/pdq/treatment/wilms/HealthProfessional/page4. Accessed June 16, 2014. 9. van den Heuvel-Eibrink MM, van Tinteren H, Rehorst H, et al. Malignant rhabdoid tumours of the kidney (MRTKs), registered on recent SIOP protocols from 1993 to 2005: a report of the SIOP renal tumour study group. Pediatr Blood Cancer. 2011;56:733–737. 10. Syzmanski KM, Tabib CH, Idrees MT, et al. Synchronous perivesical and renal rhabdoid tumor in a 9-year-old boy: a case report and review of literature. Urology. 2013;82:1158–1160.
4. Siegel MJ. Pediatric Body CT. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:283–321.
11. Amar AM, Tomlinson G, Green DM, et al. Clinical presentation of rhabdoid tumors of the kidney. J Pediatr Hematol Oncol. 2001;23: 105–108.
5. Prasad SR, Humphrey PA, Menias CO, et al. Neoplasms of the renal medulla: radiologic-pathologic correlation. Radiographics. 2005;25: 369–380.
12. Sharma R, Kitchen BJ, Mody R, et al. A report of renal artery embolization for hematuria facilitating neoadjuvant chemotherapy in an unresectable malignant renal rhabdoid tumor. Pediatr Surg Int. 2013;29:533–535.
46
www.jcat.org
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Rhabdoid Tumor: An Aggressive Renal Medullary Tumor of Childhood Shannon G. Farmakis, MD* and Marilyn J. Siegel, MD†
Abstract: We present a case of a renal rhabdoid tumor in a 2-month-old girl. Rhabdoid tumors are rare primary renal tumors in children, but they have characteristic features—medullary sinus invasion and subcapsular fluid collections—which enable a specific diagnosis. The classic imaging characteristics of this tumor compared to other more common primary pediatric renal tumors will be reviewed. Key Words: rhabdoid tumor, renal, pediatric, medullary (J Comput Assist Tomogr 2015;39: 44–46)
R
habdoid tumors (RTs) account for approximately 0.9% to 2% of renal tumors in children.1 The entity was first described in 1978 as a sarcomatoid variant of Wilms tumor but was quickly recognized to represent a unique entity.2 Distinguishing these tumors from other primary renal tumors in children is important as the treatment and prognosis are different.
CASE REPORT A previously healthy 2-month-old girl presented to an outside emergency department with a 1-week history of increased fussiness, decreased appetite, emesis, and increasing abdominal distension. Pertinent laboratory values included decreased hemoglobin and hematocrit as well as hematuria. Ionized calcium levels were eventually obtained which were mildly elevated at 5.32 mg/dL (reference range, 3.9–5.2 mg/dL). An ultrasound was performed which revealed a large heterogeneous mass arising from the right kidney with large areas of peripheral necrosis (Fig. 1). After transfer to our institution, a computed tomography of abdomen/pelvis was obtained which showed a large mass arising from the right kidney and occupying most of the right hemiabdomen (Fig. 2). Large peripheral subcapsular fluid collections were seen within the mass. The mass compressed the inferior vena cava, and multiple collateral vessels were seen, including a dilated azygos vein and paravertebral venous plexuses. There was no evidence of metastatic disease to the chest. The patient underwent a radical right nephrectomy with regional lymphadenectomy (Fig. 3). Histologic findings revealed a malignant RT that involved the renal hilum and sinuses; however, there was no evidence of vascular invasion or capsular extension. INI-1 immunostaining confirmed loss of the INI-1 gene. Bone scintigraphy and magnetic resonance imaging (MRI) of the brain did not show evidence of metastatic disease. The patient was subsequently treated with vincristine, cisplatin, doxorubicin, and cyclophosphamide. Serial imaging scans during an 8-month period From the *Department of Radiology, St Louis University School of Medicine; and †Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, MO. Received for publication October 27, 2014; accepted October 31, 2014. Reprints: Shannon G. Farmakis, MD, Department of Radiology, St Louis University School of Medicine, 3635 Vista Av at Grand Blvd, St Louis, MO (e‐mail: [email protected]). An expanded discussion of this “Case of the Quarter” can be found at the SCBTMR Web site: scbtmr.dnnstaging.com. The authors declare no conflict of interest. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
44
www.jcat.org
showed no evidence of local recurrence. However, a surveillance brain MRI showed a nonoperable pineal mass, consistent with a new primary intracranial neoplasm.
DISCUSSION Rhabdoid tumor of the kidney is an aggressive embryonal tumor, which arises from primitive cells in the renal medulla and frequently involves the hilum and collecting system.3–5 It accounts for less than 2% of childhood renal tumors and is associated with loss or inactivation of the SMARCB1 gene, also referred to as the BAF47, SNF5, or INI1 tumor suppressor gene, on chromosome 22q.1,6 This mutation can be inherited or arise somatically. Approximately 10% to 15% of affected children have primary brain tumors, including RT, ependymoma, astrocytoma, and primitive neuroectodermal tumors.1,2,7 The brain tumor is usually near the midline and in the posterior fossa. Primary RTs of the brain are also referred to as atypical rhabdoid/teratoid tumors.1 The median age of patients with renal RT is 18 months with a mean age of 11 months.8 It affects boys slightly more commonly than girls (1.5:1).9 The common symptoms at presentation include gross hematuria, hypercalcemia related to elevated serum parathormone levels, abdominal distension or pain, fussiness, and fever.7,9–12 Staging of renal RTs is based on the Children's Oncology Group staging of Wilms tumors after surgical resection of the mass. More than two thirds of patients with RT have advanced disease at presentation, usually with metastases to the lungs and brain.8,9 Ten to 15% of patients will have intracranial lesions.8 Prognosis varies with patient age. Overall survival is poor in young patients with infants younger than 6 months having a survival rate of 9% compared to those older than 2 years having a 41% overall survival.8 Most patients present with advanced disease (stage III 55% and stage IV 24%) compared to stage I and II disease (3% and 18%, respectively).9 Radical surgical resection with lymph node dissection is the treatment of choice followed by chemotherapy.10 No specific combination of chemotherapeutic agents has proven to be best in treating this tumor. Various combinations have been used including ifosfamide, carboplatin, and etoposide, etoposide and ifosfamide, and cisplatin and etoposide.8 Although RTs have been reported to involve both kidneys, most cases are solitary (96%).2,9 On computed tomography, RT appears as a large, heterogeneous, infiltrative intrarenal mass with indistinct margins and infiltration of the renal hilum. Additional findings include renal capsular thickening, a peripheral crescentic subcapsular fluid collection representing a tumoral necrosis and/ or hemorrhage, and calcifications.2–5,7 The peripheral collection is a characteristic occurring in approximately 70% of patients with RT compared to only 12% in other pediatric renal tumors, such as Wilms tumor, mesoblastic nephroma, clear-cell sarcoma, and rarely renal cell carcinoma and undifferentiated sarcoma.7 The tumor may extend into the renal vein or inferior vena cava.11 The increased incidence of second primary tumors in the brain in these patients makes an imaging diagnosis important, as MRIs of the brain and
J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Rhabdoid Tumor
FIGURE 1. A, Longitudinal sonogram of the right kidney demonstrates a large heterogeneous, echogenic renal mass (arrowheads) replacing most of the kidney. Also noted is a large peripheral subcapsular fluid collection with internal septations (arrows). This appearance is characteristic of renal RT. B, Transverse image of the right kidney with color Doppler demonstrates minimal vascularity in the solid portion of the mass. Figure 1 can be viewed online in color at www.jcat.org.
FIGURE 2. A and B, Axial images and (C) coronal reconstruction of the abdomen and pelvis demonstrate a large infiltrative mass (M) arising from the right kidney and infiltrating the central renal sinus and a large peripheral subcapsular fluid collection (arrows). The tumor displaces bowel to the left. Open arrow indicates residual enhancing renal parenchyma.
central nervous system are not routinely obtained in the metastatic workup of most pediatric renal masses but should be performed in children with renal RTs. The differential diagnostic considerations of RT include Wilms tumor, renal cell carcinoma, and clear-cell sarcoma. Wilms tumor is the most common renal tumor in childhood, accounting for more than 85% of renal masses. Renal cell carcinoma is very rare in childhood. However, it can be seen in older children (typically second decade of life). Unlike RT, Wilms tumor and renal cell carcinoma arise in the renal cortex. Both tend to be well circumscribed, large, heterogeneous masses, and they distort rather than infiltrate the adjacent parenchyma.3,4 Although imaging findings are similar, the patient age is helpful in separating these 2 entities. Clear-cell sarcoma is another extremely rare pediatric tumor. It most often affects children age 1 to 4 years. Like RT, it arises in the renal medulla and infiltrates the kidney, but it typically contains large cystic areas, and it is the only pediatric renal malignancy that commonly metastasizes to the bone.3–5
CONCLUSIONS In conclusion, RT is a rare and aggressive primary pediatric renal tumor that arises from the renal medulla, invades the renal hilum
FIGURE 3. Gross specimen of resected tumor cut in half shows the solid component of the tumor and large subcapsular fluid collections (arrows) representing areas of hemorrhagic necrosis. (Photograph courtesy of Louis P. Dehner, MD.) Figure 3 can be viewed online in color at www.jcat.org.
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.jcat.org
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J Comput Assist Tomogr • Volume 39, Number 1, January/February 2015
Farmakis and Siegel
and collecting system, and classically appears as an infiltrative mass with a peripheral subcapsular fluid collection representing hemorrhagic necrosis. It needs to be included in the differential diagnostic considerations of renal masses in a young pediatric population as an imaging-based diagnosis can direct the clinicians to do a more appropriate metastatic workup for this tumor compared to that performed for other pediatric renal tumors. REFERENCES 1. Heck JE, Lombardi CA, Cockburn M, et al. Epidemiology of rhabdoid tumors of early childhood. Pediatr Blood Cancer. 2013;60:77–81. 2. Chang CJ, Yeh ML, Chen CC. Rhabdoid tumor of the kidney with spontaneous rupture: case report and review of literature. Pediatr Surg Int. 2008;24:451–453. 3. Lowe LH, Isuani BH, Heller RM, et al. Pediatric renal masses: Wilms tumor and beyond. Radiographics. 2000;20:1585–1603.
6. Dome JS, Fernandez CV, Mullen EA. Children's oncology group’s 2013 blueprint for research: renal tumors. Pediatr Blood Cancer. 2013;60: 994–1000. 7. Agrons GA, Kingsman KD, Wagner BJ, et al. Rhabdoid tumor of the kidney in children: a comparative study of 21 cases. Am J Roentgenol. 1997;168:447–451. 8. United States. National Cancer Institute (2014) Wilms tumor and other childhood kidney tumors treatment (PDQ®). http://www.cancer.gov/ cancertopics/pdq/treatment/wilms/HealthProfessional/page4. Accessed June 16, 2014. 9. van den Heuvel-Eibrink MM, van Tinteren H, Rehorst H, et al. Malignant rhabdoid tumours of the kidney (MRTKs), registered on recent SIOP protocols from 1993 to 2005: a report of the SIOP renal tumour study group. Pediatr Blood Cancer. 2011;56:733–737. 10. Syzmanski KM, Tabib CH, Idrees MT, et al. Synchronous perivesical and renal rhabdoid tumor in a 9-year-old boy: a case report and review of literature. Urology. 2013;82:1158–1160.
4. Siegel MJ. Pediatric Body CT. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2008:283–321.
11. Amar AM, Tomlinson G, Green DM, et al. Clinical presentation of rhabdoid tumors of the kidney. J Pediatr Hematol Oncol. 2001;23: 105–108.
5. Prasad SR, Humphrey PA, Menias CO, et al. Neoplasms of the renal medulla: radiologic-pathologic correlation. Radiographics. 2005;25: 369–380.
12. Sharma R, Kitchen BJ, Mody R, et al. A report of renal artery embolization for hematuria facilitating neoadjuvant chemotherapy in an unresectable malignant renal rhabdoid tumor. Pediatr Surg Int. 2013;29:533–535.
46
www.jcat.org
© 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
