Letters to the Editor
249
Prenatal diagnosis of orbital melanotic neuroectodermal tumor in infancy Prenatal orbital tumors are rare, with various diagnoses possible. We report a case of orbital melanotic neuroectodermal tumor in infancy (MNTI), suggested prenatally on ultrasound examination and elucidated by subsequent magnetic resonance imaging (MRI). A 30-year-old woman was referred to our center at 36 weeks’ gestation because of a fetal periorbital mass discovered on routine ultrasound examination. Further ultrasound examination confirmed a homogeneous right periorbital soft-tissue mass (Figure S1), with no hypervascularization on color Doppler. MRI of the fetal brain at 37 weeks’ gestation showed a well-circumscribed tumor of 40 mm in diameter centered on the right zygoma, with a homogeneous high signal on T1-weighted imaging (Figure 1) and low signal intensity on T2 (Figure 2). Based on MRI analysis, the suggested diagnosis was a fat-containing tumor such as lipoblastoma or teratoma. At 40 weeks’ gestation, a male neonate was delivered by Cesarean section and presented right infraorbital and jaw swelling, with blackish-blue freckles in the overlying skin (Figure S2). Computed tomography displayed a homogeneously hyperdense mass around the zygoma, with no calcification or fat density. On postnatal MRI, the lesion had a homogeneous high signal intensity on T1, with no signal loss on fat-saturated T1 or modification after gadolinium injection, and low signal intensity on T2* and T2. Based on these findings, a melanin-containing tumor was suggested. At 3 weeks of age, a percutaneous biopsy was performed which showed a dark biopsy specimen on macroscopic examination. A histological diagnosis of MNTI, otherwise called melanotic progonoma, was
Figure 1 Well-circumscribed right periorbital mass with homogeneous high signal intensity on T1-weighted axial orbital magnetic resonance imaging in a fetus at 37 weeks’ gestation.
Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Ultrasound Obstet Gynecol 2015; 46: 247–252.
Letters to the Editor
250
Calcified tumors may show high T1 signal intensity, but calcifications usually do not involve the entire tumor. In conclusion, this case highlights the central role played by fetal MRI in the diagnosis of orbital MNTI, based on the paramagnetic effect of melanin that gives characteristically high signal intensity on T1-weighted MRI. Therefore, MNTI is a diagnosis to consider in cases of fetal periorbital tumor presenting with homogeneous high signal intensity on T1-weighted imaging, absence of signal loss with fat-suppressed T1 and low signal intensity on T2-weighted imaging.
Acknowledgment We are grateful to Dr C. Colmant, obstetrician, for providing the prenatal ultrasound image.
Figure 2 Right periorbital mass with homogeneous very low signal intensity on T2-weighted coronal orbital magnetic resonance imaging in a fetus at 37 weeks’ gestation.
made. Given the location of the lesion, chemotherapy was initiated to reduce the size of the tumor; this was followed by radical surgery 2 months later. At the time of the last MRI, 2 months after surgery, the child was disease free. We report the first case of MNTI to be diagnosed in utero and in the uncommon location of the orbital wall. MNTI is a rare benign tumor, observed typically in the maxilla of infants before 1 year of age1 . Preferential location for development of MNTI is the head and neck (maxillary (61.4%), skull (15.7%) and mandible (6.4%))2 , but an orbital location is unusual3 . This rapidly growing tumor is aggressive locally, but prognosis is excellent after radical surgery. The rate of relapse is about 20%, mostly in cases of incomplete resection2 . Chemotherapy is used when initial complete resection is not achievable. Malignant degeneration is uncommon. Prenatal orbital tumors are rare, and many diagnoses can be suggested (Ewing sarcoma, rhabdomyosarcoma, neuroblastoma metastasis, eosinophilic granuloma)4 ; however, none of these has specific MRI features, unlike MNTI. Indeed, the clue to diagnosis of MNTI, regardless of its location, is its high signal intensity on T1 and low signal intensity on T2 MRI, related to the paramagnetic effect of melanin. Differential diagnosis of soft-tissue tumors, with high T1 signal intensity distinguishing melanin-containing tumors, includes lipid-, methemoglobin- or calcium-containing tumors5 . Lipid-containing lesions are excluded easily as they demonstrate signal loss with fat-suppressed T1 imaging. Hemorrhagic tumors may exhibit high T1 signal intensity, but with a heterogeneous appearance.
Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
M. Koob*†‡, C. Fayard§, D. Pariente§, C. Adamsbaum§ and S. Franchi-Abella§ †Service de Radiop´ediatrie et Imagerie 2, CHU de Strasbourg, Hopital de Hautepierre, ˆ Strasbourg, France; ‡Laboratoire ICube, Universit´e de Strasbourg et CNRS, Strasbourg, France; §Service de Radiop´ediatrie, Hopital Bicˆetre, ˆ Le Kremlin Bicˆetre, France *Correspondence. ([email protected]) DOI: 10.1002/uog.14787
References 1. Nazira B, Gupta H, Chaturvedi A K, Rao S A, Jena A. Melanotic neuroectodermal tumor of infancy: discussion of a case and a review of the imaging findings. Cancer imaging 2009; 9: 121–125. 2. Kruse-Losler B, Gaertner C, Burger H, Seper L, Joos U, Kleinheinz J. Melanotic neuroectodermal tumor of infancy: systematic review of the literature and presentation of a case. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 102: 204–216. 3. Nakanishi K, Hori H, Matsubara T, Matsuda K, Deguchi T, Komada Y. Recurrent melanotic neuroectodermal tumor in the orbit successfully treated with resection followed by pediculated periosteal flaps. Pediatr Blood Cancer 2008; 51: 430–432. 4. Chung E M, Smirniotopoulos J G, Specht C S, Schroeder J W, Cube R.. From the archives of the AFIP: Pediatric orbit tumors and tumorlike lesions: nonosseous lesions of the extraocular orbit. Radiographics 2007; 27: 1777–1799. 5. Ginat D T, Meyers S P. Intracranial lesions with high signal intensity on T1-weighted MR images: differential diagnosis. Radiographics 2012; 32: 499–516.
SUPPORTING INFORMATION ON THE INTERNET The following supporting information may be found in the online version of this article: Figure S1 Prenatal axial ultrasound image in the orbital plane showing a homogeneous isoechoic soft-tissue mass in the right periorbital region, encasing the right ocular globe, at 36 weeks’ gestation. Figure S2 Neonate at birth, presenting with substantial right infraorbital and jaw swelling with occlusion of the eyelid as well as blackish freckles in overlying skin.
Ultrasound Obstet Gynecol 2015; 46: 247–252.
249
Prenatal diagnosis of orbital melanotic neuroectodermal tumor in infancy Prenatal orbital tumors are rare, with various diagnoses possible. We report a case of orbital melanotic neuroectodermal tumor in infancy (MNTI), suggested prenatally on ultrasound examination and elucidated by subsequent magnetic resonance imaging (MRI). A 30-year-old woman was referred to our center at 36 weeks’ gestation because of a fetal periorbital mass discovered on routine ultrasound examination. Further ultrasound examination confirmed a homogeneous right periorbital soft-tissue mass (Figure S1), with no hypervascularization on color Doppler. MRI of the fetal brain at 37 weeks’ gestation showed a well-circumscribed tumor of 40 mm in diameter centered on the right zygoma, with a homogeneous high signal on T1-weighted imaging (Figure 1) and low signal intensity on T2 (Figure 2). Based on MRI analysis, the suggested diagnosis was a fat-containing tumor such as lipoblastoma or teratoma. At 40 weeks’ gestation, a male neonate was delivered by Cesarean section and presented right infraorbital and jaw swelling, with blackish-blue freckles in the overlying skin (Figure S2). Computed tomography displayed a homogeneously hyperdense mass around the zygoma, with no calcification or fat density. On postnatal MRI, the lesion had a homogeneous high signal intensity on T1, with no signal loss on fat-saturated T1 or modification after gadolinium injection, and low signal intensity on T2* and T2. Based on these findings, a melanin-containing tumor was suggested. At 3 weeks of age, a percutaneous biopsy was performed which showed a dark biopsy specimen on macroscopic examination. A histological diagnosis of MNTI, otherwise called melanotic progonoma, was
Figure 1 Well-circumscribed right periorbital mass with homogeneous high signal intensity on T1-weighted axial orbital magnetic resonance imaging in a fetus at 37 weeks’ gestation.
Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
Ultrasound Obstet Gynecol 2015; 46: 247–252.
Letters to the Editor
250
Calcified tumors may show high T1 signal intensity, but calcifications usually do not involve the entire tumor. In conclusion, this case highlights the central role played by fetal MRI in the diagnosis of orbital MNTI, based on the paramagnetic effect of melanin that gives characteristically high signal intensity on T1-weighted MRI. Therefore, MNTI is a diagnosis to consider in cases of fetal periorbital tumor presenting with homogeneous high signal intensity on T1-weighted imaging, absence of signal loss with fat-suppressed T1 and low signal intensity on T2-weighted imaging.
Acknowledgment We are grateful to Dr C. Colmant, obstetrician, for providing the prenatal ultrasound image.
Figure 2 Right periorbital mass with homogeneous very low signal intensity on T2-weighted coronal orbital magnetic resonance imaging in a fetus at 37 weeks’ gestation.
made. Given the location of the lesion, chemotherapy was initiated to reduce the size of the tumor; this was followed by radical surgery 2 months later. At the time of the last MRI, 2 months after surgery, the child was disease free. We report the first case of MNTI to be diagnosed in utero and in the uncommon location of the orbital wall. MNTI is a rare benign tumor, observed typically in the maxilla of infants before 1 year of age1 . Preferential location for development of MNTI is the head and neck (maxillary (61.4%), skull (15.7%) and mandible (6.4%))2 , but an orbital location is unusual3 . This rapidly growing tumor is aggressive locally, but prognosis is excellent after radical surgery. The rate of relapse is about 20%, mostly in cases of incomplete resection2 . Chemotherapy is used when initial complete resection is not achievable. Malignant degeneration is uncommon. Prenatal orbital tumors are rare, and many diagnoses can be suggested (Ewing sarcoma, rhabdomyosarcoma, neuroblastoma metastasis, eosinophilic granuloma)4 ; however, none of these has specific MRI features, unlike MNTI. Indeed, the clue to diagnosis of MNTI, regardless of its location, is its high signal intensity on T1 and low signal intensity on T2 MRI, related to the paramagnetic effect of melanin. Differential diagnosis of soft-tissue tumors, with high T1 signal intensity distinguishing melanin-containing tumors, includes lipid-, methemoglobin- or calcium-containing tumors5 . Lipid-containing lesions are excluded easily as they demonstrate signal loss with fat-suppressed T1 imaging. Hemorrhagic tumors may exhibit high T1 signal intensity, but with a heterogeneous appearance.
Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
M. Koob*†‡, C. Fayard§, D. Pariente§, C. Adamsbaum§ and S. Franchi-Abella§ †Service de Radiop´ediatrie et Imagerie 2, CHU de Strasbourg, Hopital de Hautepierre, ˆ Strasbourg, France; ‡Laboratoire ICube, Universit´e de Strasbourg et CNRS, Strasbourg, France; §Service de Radiop´ediatrie, Hopital Bicˆetre, ˆ Le Kremlin Bicˆetre, France *Correspondence. ([email protected]) DOI: 10.1002/uog.14787
References 1. Nazira B, Gupta H, Chaturvedi A K, Rao S A, Jena A. Melanotic neuroectodermal tumor of infancy: discussion of a case and a review of the imaging findings. Cancer imaging 2009; 9: 121–125. 2. Kruse-Losler B, Gaertner C, Burger H, Seper L, Joos U, Kleinheinz J. Melanotic neuroectodermal tumor of infancy: systematic review of the literature and presentation of a case. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 102: 204–216. 3. Nakanishi K, Hori H, Matsubara T, Matsuda K, Deguchi T, Komada Y. Recurrent melanotic neuroectodermal tumor in the orbit successfully treated with resection followed by pediculated periosteal flaps. Pediatr Blood Cancer 2008; 51: 430–432. 4. Chung E M, Smirniotopoulos J G, Specht C S, Schroeder J W, Cube R.. From the archives of the AFIP: Pediatric orbit tumors and tumorlike lesions: nonosseous lesions of the extraocular orbit. Radiographics 2007; 27: 1777–1799. 5. Ginat D T, Meyers S P. Intracranial lesions with high signal intensity on T1-weighted MR images: differential diagnosis. Radiographics 2012; 32: 499–516.
SUPPORTING INFORMATION ON THE INTERNET The following supporting information may be found in the online version of this article: Figure S1 Prenatal axial ultrasound image in the orbital plane showing a homogeneous isoechoic soft-tissue mass in the right periorbital region, encasing the right ocular globe, at 36 weeks’ gestation. Figure S2 Neonate at birth, presenting with substantial right infraorbital and jaw swelling with occlusion of the eyelid as well as blackish freckles in overlying skin.
Ultrasound Obstet Gynecol 2015; 46: 247–252.
