An Unusual Oral Mass

Electronic Clinical Challenges and Images in GI An Unusual Oral Mass Lorenzo Mannelli,* Mai Vi H. Hoang,* Annette P. Sabath,‡ and Ken F. Linnau* Department of *Radiology and ‡Pathology, University of Washington, Seattle, Washington

Question: A 72-year-old man with a recent history of dental crown placement and a root canal procedure complained of right-sided mouth pain, numbness, and lip paresthesia. A mandibular lytic lesion was noted on orthopantomogram (Figure A, arrow) and magnetic resonance imaging (MRI) was subsequently requested. The patient was claustrophobic and the MRI was interrupted after the acquisition of the T1 and diffusion-weighted images. The MRI showed a 4 ⫻ 3.5-cm mass in the right masticator space, centered at and eroding the right mandibular condyle. The mass was hyperintense on T1-weighted images (Figure B, arrow), and showed restricted diffusion on the apparent diffusion coefficient map obtained from diffusion weighted image (Figure C). A core biopsy was obtained (Figure D; H&E staining). Further, his past history revealed alcoholic cirrhosis and prostate carcinoma treated 10 years earlier with brachytherapy, remote history of basal cells carcinoma of the face. What is the diagnosis? See the GASTROENTEROLOGY web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Conflicts of interest: The authors disclose no conflicts. © 2012 by the AGA Institute 0016-5085/$36.00 doi:10.1053/j.gastro.2011.08.047

GASTROENTEROLOGY 2012;142:e14 – e15

Electronic Clinical Challenges and Images in GI, continued Answer to the Clinical Challenges and Images in GI Question: Image 3: Metastatic Hepatocellular Carcinoma Metastatic hepatocellular carcinoma (HCC) of the mandible without lung involvement is a rare entity, with only 58 cases reported in the literature since 1957.1 In addition to the characteristic cellular pattern at pathology, an immunohistochemistry HepPar-1 stain (Figure E) was used to confirm the liver as the organ of origin. A contrast-enhanced multiphasic CT of the liver demonstrated advanced cirrhosis and multiple liver HCCs, all ⬍2 cm in size (Figure F, arrow). CT-positron emission tomography showed metastatic spread to the bones (Figure G, arrow), but absence of metastasis to the lungs. The apparent diffusion coefficient was 0.96 ⫻ 10–3mm2/s, within the reported range for HCC.2 There are 2 hypothesized routes of cancerous seeding to the mandible from the liver: The first via hematogenous spread from the arterially rich portal vein and hepatic artery.3 However, any oral lesions from this route would theoretically have associated pulmonary metastasis.3 This was not the case with our patient. The other postulated route is through the Batson’s plexus or the Batson’s veins, which are a circuitry of valveless veins that connect the deep pelvic veins and the thoracic veins to the internal vertebral venous plexuses.3 This network circumvents the lungs and may be the primary route of seeding to the spine and vertebral bodies, which are a common site of metastasis seen in HCC.3 The patient was managed with palliative treatment consisting of radiation therapy to the bone metastasis and systemic treatment with Sorafenib. After 7 months, the patient is alive and followed by hospice care. References 1. Dick A, Mead SG, Mensh M, et al. Primary hepatoma with metastasis to the mandible. Am J Surg 1957;94:846 – 850. 2. Mannelli L, Kim S, Hajdu CH, et al. Assessment of tumor necrosis of hepatocellular carcinoma after chemoembolization: diffusion-weighted and contrast-enhanced MRI with histopathologic correlation of the explanted liver. AJR Am J Roentgenol 2009;193:1044 –1052. 3. Fujihara H, Chikazu D, Saijo H, et al. Metastasis of hepatocellular carcinoma into the mandible with radiographic findings mimicking a radicular cyst: a case report. J Endod 2010;36:1593–1596. For submission instructions, please see the GASTROENTEROLOGY web site (www.gastrojournal.org).

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