|Year : 2019 | Volume
| Issue : 2 | Page : 237-240
Oncology and pregnancy: Image wisely
Mayur Burrewar, Tanvi Vaidya, Anurag Gupta, Abhishek Mahajan
Department of Radiodiagnosis and Imaging, Tata Memorial Hospital, Homi Bhabha National Institute (HBNI), Mumbai, Maharashtra, India
|Date of Web Publication||20-Dec-2019|
Department of Radiodiagnosis and Imaging, Tata Memorial Hospital, Dr E Borges Road, Parel, Mumbai - 400 012, Maharashtra; Homi Bhabha National Institute (HBNI), Mumbai, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Burrewar M, Vaidya T, Gupta A, Mahajan A. Oncology and pregnancy: Image wisely. Cancer Res Stat Treat 2019;2:237-40
| Case History and Approach|| |
A 28-week-old pregnant female presented with progressively increasing swelling over the right lower jaw for 2½ months. On examination, a large growth was seen involving the right lower half of the face and floor of the mouth on the right side. An orthopantomogram (OPG) was done [Figure 1]. To avoid radiation hazards, noncontrast magnetic resonance imaging (MRI) of the head and neck (with diffusion-weighted imaging [DWI]) [Figure 2] and limited low-dose computed tomography (CT) cuts of involved segment for disease characterization were performed [Figure 3]. Three-dimensional volume-rendered image helped in better understanding of disease before planning of definitive therapy, as shown in [Figure 4].
|Figure 2: Magnetic resonance imaging sequences: (a) Axial T1 (b) Axial T2 (c) Coronal T2 (d) Sagittal T2|
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|Figure 3: Computed tomography cuts (a) axial soft-tissue window (b) axial bone window (c) coronal soft-tissue window (d) coronal bone window|
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What is the diagnosis? Once you have finalized your answer, please turn to page 238 to read on.
| Imaging Findings|| |
The OPG revealed a large soft tissue mass with sunburst periosteal reaction with irregular right mandibular cortex [Figure 1].
MRI revealed an expansile soft-tissue lesion with osseous matrix epicentered around the right hemimandible, involving the floor of the mouth. T1- and T2-weighted images revealed large areas of low-signal intensity with an intervening soft tissue and sunburst periosteal appearance representing new bone formation [Figure 2]. Limited CT cuts were taken for matrix characterization, extent of bone erosion, and infratemporal fossa extension, which revealed an expansile lytic lesion with osseous matrix of the right hemimandible involving its angle and body causing cortical erosion and new bone formation in the form of sunburst spiculated periosteal reaction, as depicted in [Figure 3].
| Diagnosis|| |
Imaging diagnosis of osteosarcoma was made which was deemed to be locally resectable. On needle biopsy, histopathological report showed chondroblastic osteosarcoma. For further staging, whole-body DWI and low-dose non-contrast thorax CT with abdominal shield were done revealing no other metastatic focus of osteosarcoma elsewhere.
| Management|| |
The patient was planned for induction of labor at 35 weeks through vaginal delivery followed by surgery with jaw reconstruction and postoperative external-beam radiation therapy. The patient was disease-free on recent follow-up examination done after 4 months of surgery.
| Case Discussion|| |
Osteosarcoma is the most common malignant primary bone tumor affecting predominantly young adults and adolescent age groups. There are multiple proven risk factors for osteosarcoma such as 10–30-year age group, male gender, tall height, radiation exposure, certain bone disorders (Paget's disease and hereditary multiple osteochondroma), and inherited cancer syndromes (retinoblastoma, Li–Fraumeni syndrome, and Rothmund-Thomson syndrome). Occurrenceof bone- and soft-tissue tumors during pregnancy is rare. Only 137 well-documented cases have been reported in the English literature between 1963 and 2014, of which only 38 were bone tumors and the rest were arising from the soft tissue.
Mandibular osteosarcoma also known as gnathic osteosarcoma is considered a distinct entity because of predilection for older patients; the mean age of occurrence is 34–36 years. Mandibular osteosarcoma constitutes 6% of total osteosarcomas. It is slightly different than appendicular osteosarcoma; the mean age of the occurrence of gnathic osteosarcoma is two decades later than appendicular osteosarcoma. Gnathic osteosarcoma has a greater chance of local recurrence than appendicular osteosarcoma, and it is refractory to chemotherapy. There are two types of mandibular osteosarcoma, namely primary and secondary., Secondary gnathic osteosarcoma is more common than primary and predisposing factors include underlying bone disease such as Paget's or fibrous dysplasia. Common presenting complaints include swelling, loss and displacement of teeth, spasm, and local paresthesia; it is often misdiagnosed with chronic pulpitis or chronic periodontitis. The condition is usually not associated with pain. Most patients present after dental treatment and relate the symptoms to tooth extraction., The radiographic appearances are of both osteolytic and osteogenic patterns. The osteogenic pattern almost always shows an area of the typical sunburst appearance, which on radiography is seen as stippled bone pattern with destruction of the cortical outlines and perpendicular striae (Sharpey's fibers) of periosteal reaction. The periodontal ligament space widening or attenuation of surrounding lamina dura are the common radiographic findings.
CT scan and MRI are the imaging modalities of importance for evaluating the extent of the tumor and to assess its relationship to adjacent tissues and bones. CT is superior to magnetic resonance to assess adjacent bony involvement. On MRI, ossified newly formed periosteal bone reaction shows low signal on all of the sequences, and the actively proliferating soft-tissue mass is seen. This soft tissue shows heterogeneous enhancement on contrast imaging. On CT imaging, the mass shows thin irregular spicules of new bone formation which are perpendicular to the epicenter of the lesion, giving the classic sunburst appearance. The OPG reveals characteristic features such as stippled bone pattern and destruction of cortical outlines with perpendicular spiculations of periosteal new bone formation.
Clinically, gnathic osteosarcoma is more aggressive locally than appendicular osteosarcoma although having the same histology. The common histologic variants, on the basis of the type of extracellular matrix produced by the tumor cells are osteoblastic, fibroblastic, chondroblastic, and mixed osteosarcoma. Other less common histologic variants include myxomatous, telangiectatic, epithelioid, fibrous histiocytoma-like, giant cell, small cell, and large-cell osteosarcoma. Abnormal spindle cells in osteosarcoma produce osteoid or immature bone. Mandibular osteosarcoma is histologically more differentiated than appendicular osteosarcoma., Clinicoradiopathological correlation is helpful in cases of bland histological findings. Osteonectin (specific) and alkaline phosphatase (non-specific) are raised and can be used as biochemical markers for osteosarcoma. Apart from necrosis, the expression of HER2/CerbB2, gains and loss of specific chromosomes, loss of RB and p53 gene heterozygosity, overexpression of P-glycoprotein, MDM2 overexpression, and amplification are found to be molecular makers for low grade and dedifferentiated mandibular osteosarcoma. ER and PR positivity are also known associations with highly differentiated osteosarcoma (40% and 32.3%, respectively)., The spread of mandibular osteosarcoma is microscopic through the narrow spaces, mandibular canal, periodontal ligament, and mental and inferior alveolar nerve along which an intra-osseous lesion can spread to soft tissues.,
Imaging in pregnancy
Imaging is an essential aid in the diagnostic evaluation of pathologies in pregnancy; however, there is considerable stigma regarding the safety of these modalities which may cause unnecessary avoidance of useful diagnostic tests in pregnant women and lactating mothers. Imaging modalities that can be used in pregnancy are as follows:
- Ultrasound: It is a cheap, readily available modality with no risk of ionizing radiation. There is a theoretical risk of increasing temperature of the fetus, which may be as high as 2°C at the Food and Drug Administration approved spatial peak temporal average intensity of ultrasound transducers; however, it is not possible to get sustained temperature elevation at the single fetal anatomical site., There are no documented adverse fetal effects for diagnostic ultrasound including duplex Doppler. Hence, the use of ultrasound does not pose any risk to fetus or pregnancy.
- Radiography: As low as reasonably achievable (ALARA) is a principle of radioprotection stating that whenever ionizing radiation has to be applied to humans, animals or materials, the exposure should be ALARA. The use of ionizing radiation and its adverse effects depend on the gestational age and doses of radiation. There is no risk to lactation from the external source of ionizing radiation. The fetal damage has not been reported with radiation exposure <50 mGy, which is well above the range of exposure for diagnostic procedures. There is no proven teratogenic risk for the fetus with >25 weeks of gestation with diagnostic radiation doses of <100 mGy
- CT: A CT scan involves exposure to radiation at levels slightly higher than normal X-rays. However, the maternal benefit from the early diagnosis of some acute conditions may outweigh the possible fetal risks. Animal studies have shown no teratogenic or mutagenic risks from the use of iodinated contrast. Despite the lack of known harm, it is recommended that contrast be used only to obtain additional diagnostic information which will affect the care of the fetus and the woman during pregnancy. Breastfeeding can be continued without interruption after the administration of an intravenous iodinated contrast agent,
- MRI: It is superior to ultrasound and CT for imaging in pregnancy, being nonionizing and nonoperator dependent. There are theoretical risks of teratogenesis, tissue damage, and acoustic heating, but there is no actual evidence of adverse effects. The use of gadolinium-based contrast agents has probable fetal adverse effects as gadolinium can cross the placental barrier and free gadolinium is toxic. Animal studies have shown the adverse teratogenic effects of gadolinium use, but no such adverse effects are reported in humans even when used in first trimester and lactation. Gadolinium use should be limited to situations where the benefits clearly outweigh the possible risk. There are no data regarding the use of superparamagnetic iron oxide contrasts in pregnancy and lactation, so if contrast is to be used, then gadolinium is always recommended. Breastfeeding should not be interrupted after gadolinium administration.
The potential deterministic effects on the fetus are summarized in [Table 1]. There is a potential role of whole-body diffusion MRI for the staging of cancers in pregnancy as it prevents exposure to ionizing radiation.
|Table 1: Potential deterministic effects of radiation exposure in pregnancy on the fetus|
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Other differentials of this type of presentation include odontomas, odontogenic myomas, solitary plasmacytomas, squamous cell carcinoma of the mandible, central hemangioma, fibrous dysplasia, and metastatic lesions.
| Conclusion|| |
The safety of diagnostic imaging in pregnancy is a real concern. There should be careful decision-making process weighing the risks and benefits of any radiographic procedure including discussion with mother. Furthermore, gnathic osteosarcoma is a rare mimic of aggressive dental pathologies and lack of awareness leads to delayed diagnosis. Timely radiopathological diagnosis and depiction of the extent of disease using appropriate imaging are essential for prompt surgical resection.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published, and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Turkar S. Current treatment landscape and emerging management options for extremity sarcoma. Cancer Res Stat Treat 2018;1:121-38. [Full text]
Zarkavelis G, Petrakis D, Fotopoulos G, Mitrou S, Pavlidis N. Bone and soft tissue sarcomas during pregnancy: A narrative review of the literature. J Adv Res 2016;7:581-7.
Clark JL, Unni KK, Dahlin DC, Devine KD. Osteosarcoma of the jaw. Cancer 1983;51:2311-6.
Mahajan A, Vaish R, Desai S, Arya S, Sable N, K D'cruz A, et al.
Gnathic osteosarcoma: Clinical, radiologic, and pathologic review of bone beard tumor. J Glob Oncol 2017;3:823-7.
Dohi O, Hatori M, Suzuki T, Ono K, Hosaka M, Akahira J, et al.
Sex steroid receptors expression and hormone-induced cell proliferation in human osteosarcoma. Cancer Sci 2008;99:518-23.
Domínguez-Malagón HR, González-Conde E, Cano-Valdez AM, Luna-Ortiz K, Mosqueda-Taylor A. Expression of hormonal receptors in osteosarcomas of the jaw bones: Clinico-pathological analysis of 21 cases. Med Oral Patol Oral Cir Bucal 2014;19:e44-8.
Committee on Obstetric Practice. Committee opinion no 723: Guidelines for diagnostic imaging during pregnancy and lactation. Obstet Gynecol 2017;130:e210-6.
Patel SJ, Reede DL, Katz DS, Subramaniam R, Amorosa JK. Imaging the pregnant patient for nonobstetric conditions: Algorithms and radiation dose considerations. Radiographics 2007;27:1705-22.
American Institute of Ultrasound in Medicine. Statement on Mammalian Biological Effects of Heat. Laurel (MD): American Institute of Ultrasound in Medicine; 2015.
Tirada N, Dreizin D, Khati NJ, Akin EA, Zeman RK. Imaging pregnant and lactating patients. Radiographics 2015;35:1751-65.
Sachs HC; Committee On Drugs. The transfer of drugs and therapeutics into human breast milk: An update on selected topics. Pediatrics 2013;132:e796-809.
American College of Radiology. Administration of contrast media to pregnant or potentially pregnant patients. ACR manual on contrast media. Version 2008;10:95-8.
Chen MM, Coakley FV, Kaimal A, Laros RK Jr. Guidelines for computed tomography and magnetic resonance imaging use during pregnancy and lactation. Obstet Gynecol 2008;112:333-40.
Expert Panel on MR Safety, Kanal E, Barkovich AJ, Bell C, Borgstede JP, Bradley WG Jr., et al.
ACR guidance document on MR safe practices: 2013. J Magn Reson Imaging 2013;37:501-30.
Mahajan A, Santhosh Kumar GV, Vaidya T, Thakur M, Desai S. Potential role of whole-body diffusion magnetic resonance imaging in tumor staging for pregnant patients with cancer. Indian J Cancer 2018;55:417-8.
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[Figure 1], [Figure 2], [Figure 4], [Figure 3]