CASE 15395 Published on 20.03.2018

Teaching Case

Section

Head & neck imaging

Case Type

Clinical Cases

Authors

Dr Hemraj Salodiya¹, Dr Shailesh Bhuriya¹, Dr Lata Kumari¹, Dr Amit Achyut Ban¹, Dr H.P. Parekh², Dr. N.U Bahri³

(1) Resident
(2) Professor
(3) Professor and Head of Department

Department of Radio-diagnosis,
Shri M.P Shah Medical College,
Guru Gobind Singh Hospital,
P.N.Marg, Jamnagar,
Gujarat, India -361008
Email ID: lataa1987@gmail.com

Patient

37 years, male

Categories

Area of Interest Head and neck ; Imaging Technique CT, MR, MR-Diffusion/Perfusion ;

Procedure Diagnostic procedure, Computer Applications-3D ; Special Focus Neoplasia ;

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Clinical History

A 37-year-old male patient presented with the complaint of swelling on the right side of the mandible for 1 year.

Differential Diagnosis List

Odontogenic myxoma of the mandible

Ameloblastomas

Keratocystic odontogenic tumours

Odontogenic cysts

Imaging Findings

CT images show well-defined expansile lesion (Fig. 1-3) involving the mandible on the right side with internal trabeculations giving soap bubble appearance (Fig. 2a, d; 3a, d - white arrows). The lesion involves the body of the mandible on the right side from the first premolar till the 3rd molar tooth, angle and ramus of the mandible on the right side with non-visualisation of the right lower second premolar and all molar teeth due to destruction by tumour spread (Fig. 2e, 4). On T2-weighted axial image (Fig. 5a), a lobulated lesion is noted which appears hyperintense (white arrow), shows internal septations (yellow arrow) and extends to involve surrounding soft tissue (red arrow). On T1-weighted axial image (Fig. 5b), the lesion appears iso to hypo-intense (white arrow) with internal septations (yellow arrow). The lesion shows no restriction (Fig. 5c - red arrow) on diffusion-weighted imaging and high ADC values (Fig. 5d - red arrow). Above imaging and histopathological findings confirm diagnosis of odontogenic myxoma.

Discussion

Odontogenic myxoma (OM) is a rare entity. Its prevalence ranges from 0.04 to 3.7%. [1] It is a benign but locally aggressive tumour that arises from mesenchymal components of the teeth. [2, 3] OM most commonly involves the mandible, with the ramus being a common site followed by the maxilla. [2] OM is more common in women in the age group of 20 to 30 years. [2, 3, 5] Clinically, OM is slow-growing and painless. Hence, patients usually present with large lesions. Tooth displacement, thinning and expansion of cortical bone are noted in larger lesions. [4, 6] Radiographically, OM has varied appearances, from being unilocular to a multilocular lesion with internal bony trabeculations. The trabeculations give a “honey-combed” appearance. [2, 7] CT typically shows an expansile lesion within the mandible with thinning and erosion of cortical plate along with intra-lesional trabeculations. CT assesses perforation and pattern of septations while radiographs allow better assessment of the definition of the lesion's margin with adjacent normal bone. [8] MRI helps to evaluate tumour contents, pattern of growth and extensions into surrounding tissue. MRI imaging of OM shows a well-defined, lobulated mass lesion appearing hyper-intense on T2-weighted images and hypo to isointense on T1-weighted images. [9, 10] OM mimics various other jaw lesions such as odontogenic and non-odontogenic cysts, ameloblastomas and keratocystic odontogenic tumours. [2] Odontogenic and non-odontogenic cysts that present as uniloculated expansile lesions in the jaw do not commonly show divergence of the roots of adjacent teeth. [11] Keratocystic odontogenic tumours are uniloculated or multi-cystic lesions with surrounding daughter cysts and no trabeculations. [12] Ameloblastomas, specifically the solid variants, are quite difficult to differentiate from OM on basis of imaging. [12] However, root erosion and tooth disruption are more common in ameloblastomas. [13] OM does not show restriction in diffusion-weighted imaging; however, odontogenic cysts, keratocystic odontogenic tumours and solid areas of ameloblastomas show restricted diffusion. [14] Although imaging helps to narrow down the differential diagnosis, histopathological correlation is required for confirmation of diagnosis and treatment protocol. Histologically, OM is non-capsulated, hence shows infiltration into the adjacent bone and soft tissue. [4] OM exhibit spindle-shaped cells in background of a loose myxoid stroma which correlates with our case. Imaging in OM is essential as the tumour can grow to considerable size with almost no complaints. Also, it helps to define the boundaries of the tumour, thus avoiding inadequate surgical excision. Regular follow up is necessary as recurrence rate is high. [15]

References

[1] P. J. Slootweg and A. R. M. Wittkampf (1986) Myxoma of the jaws. An analysis of 15 cases. Journal of Maxillofacial Surgery vol. 14, no. 1, pp. 46–52 (PMID: 3456413)

[2] G. Sivakumar, B. Kavitha, T. Saraswathi, and B. Sivapathasundharam (2008) Odontogenic myxoma of maxilla. Indian Journal of Dental Research vol. 19, no. 1, pp. 62–65 (PMID: 18245926)

[3] S. P. Reddy, A. Naag, and B. Kashyap (2010) Odontogenic myxoma: Report of two cases. National Journal of Maxillofacial Surgery vol. 1, no. 2, pp. 183–186 (PMID: 22442596)

[4] T. Lombardi, C. Lock, J. Samson, and E. W. Odell (1995) S100, alpha-smooth muscle actin and cytokeratin 19 immunohistochemistry in odontogenic and soft tissue myxomas. Journal of Clinical Pathology vol. 48, no. 8, pp. 759–762 (PMID: 7560205)

[5] Y. L. Lin and J. R. Basile (2010) A case of odontogenic myxoma with unusual histological features mimicking a fibro-osseous process. Head and Neck Pathology vol. 4, no. 3, pp. 253–256 (PMID: 20607463)

[6] K. R. Spencer and A. Smith (1998) Odontogenic myxoma: case report with reconstructive considerations. Australian Dental Journal vol. 43, no. 4 (PMID: 9775463)

[7] S. Singaraju, S. P. Wanjari, and R. N. Parwani (2010) Odontogenic myxoma of the maxilla: A report of a rare case and review of the literature. Journal of Oral and Maxillofacial Pathology vol. 14, no. 1, pp. 19–23 (PMID: 21180454)

[8] MacDonald-Jankowski DS, Yeung RW, Li T, Lee KM (1966) Computed tomography of odontogenic myxoma. Clinical Radiology 59:281-7 (PMID: 15037142)

[9] King DG, Saifuddin A, Preston HV, Hardy GJ, Reeves BF (1995) Magnetic resonance imaging of juxta-articular myxoma. Skeletal Radiol 24:145-7 (PMID: 7747183)

[10] Peterson KK, Renfrew DL, Feddersen RM, Buckwalter JA, elKhoury GY (1991) Magnetic resonance imaging of myxoid containing tumors. Skeletal Radiol 20:245-50 (PMID: 1853214)

[11] Lo Muzio, L.; Nocini, P.; Favia, G.; Procaccini, M. & Mignogna, M. D (1996) Odontogenic myxoma of the jaws: a clinical, radiologic, immunohistochemical, and ultrastructural study. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod 82(4):426-33 (PMID: 8899782)

[12] Dunfee BL, Sakai O, Pistey R, Gohel A (2006) Radiologic and pathologic characteristics of benign and malignant lesions of the mandible. RadioGraphics 26:1751–1768 (PMID: 17102048)

[13] Peltola, J.; Magnusson, B.; Happonen, R. P. & Borrman, H (1994) Odontogenic myxoma--a radiographic study of 21 tumours. Br. J. Oral Maxillofac. Surg 32(5):298-302 (PMID: 7999737)

[14] K Srinivasan,et al (2012) Diffusion-weighted imaging in the evaluation of odontogenic cysts and tumours. Br J Radiol 85(1018): e864–e870. (PMID: 22553294)

[15] C. S. Colombo and Y. Boivin (1966) Myxoma of the jaws. Oral Surgery, Oral Medicine, Oral Pathology vol. 21, no. 4, pp. 431– 436 (PMID: 5218147)

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