BACKGROUND: A malignant myoepithelioma is a rare tumor, mostly arising from the salivary glands. Myoepitheliomas of the ear have rarely been reported. The manuscript reports myoepithelial carcinoma of the external auditory canal (EAC) spreading to the infratemporal fossa. A clinician must be aware of anatomical variation of the bony EAC wall, such as the foramen of Huschke. This rare defect may be a pathway for spreading pathologies between these two anatomical regions. CASE REPORT: We present a case of osteoma-like stenosis of the EAC, which turned out to be an extremely rare malignant tumor. The preoperative MRI and PET/CT revealed that two parts of the tumor communicated through a defect in the antero-inferior portion of the bony ear canal. No distant metastases were detected. Subsequently, the tumor was resected from the ear canal and the infratemporal fossa en bloc. Perioperatively the defect in the EAC wall was suspected of the foramen of Huschke. After the surgery, the older scans of the patient from the past showed no presence of a congenital EAC wall defect. Therefore, the authors concluded that the tumor aggressively grew through the bone due to its biological nature. CONCLUSION: Malignant myoepithelioma of the external auditory canal is an extremely rare condition and could be misdiagnosed as other benign lesions. In cases of suspicious lesions, it is advisable to do a probatory biopsy from the EAC. Surgery is the treatment of choice in malignant myoepitheliomas, and regular follow-ups are essential to monitor for recurrence or metastatic disease. Any mass located at the antero-inferior portion of the EAC wall warrants close evaluation due to its potential for expansion from the EAC.

Department of Otorhinolaryngology and Head and Neck Surgery Faculty of Medicine and Dentistry Olomouc University Hospital Palacký University Olomouc Olomouc Czech Republic

Department of Pathology Faculty of Medicine and Dentistry Olomouc University Hospital Palacký University Olomouc Olomouc Czech Republic

Zobrazit více v PubMed

Kilpatrick SE, Hitchcock MG, Kraus MD, Calonje E, Fletcher CD. Mixed tumors and myoepitheliomas of soft tissue: a clinicopathologic study of 19 cases with a unifying concept. Am J Surg Pathol. 1997;21:13–22. doi: 10.1097/00000478-199701000-00002. PubMed DOI

Tran TL, Broholm H, Daugaard S, et al. Myoepithelial carcinoma of the orbit: a clinicopathological and histopathological study. APMIS. 2010;118:324–330. doi: 10.1111/j.1600-0463.2010.02593.x. PubMed DOI

Ghosh A, Saha S, Saha VP, Sadhu A, Chattopadhyay S. Infratemporal fossa myoepithelial carcinoma-a rare case report. Oral Maxillofac Surg. 2009;13:59–62. doi: 10.1007/s10006-009-0149-5. PubMed DOI

Chen KT. Myoepithelioma of the external auditory canal. J Laryngol Otol. 1982;96:955–958. doi: 10.1017/S0022215100093324. PubMed DOI

Saha VP, Pal S, Saha S, Chattopadhyay S. Myoepithelial carcinoma of the ear: a rare case report and review of the literature. Egypt J Otolaryngol. 2014;30:171–175. doi: 10.4103/1012-5574.133223. DOI

Joseph LD, Ravi Kumar A, Kannan S, Prathiba D. Malignant myoepithelioma of the mastoid region - a case report. Indian J Otolaryngol Head Neck Surg. 2007;59:194–196. doi: 10.1007/s12070-007-0059-5. PubMed DOI PMC

Dirier A, Guzel A, Karadayi B, Ozekinci SO, Tatli M. Malignant myoepithelioma of the external auditory canal: a case report. Int J Clin Pract. 2009;63:336–337. doi: 10.1111/j.1742-1241.2006.01021.x. PubMed DOI

Hasani M, Haghnegahdar A, Khojastepour L, Golbahar Haghighi MJ. Determining the existence of the foramen of Huschke in patients with temporomandibular joint disorders using cone beam computed tomography: retrospective cohort study. BMC Med Imaging. 2022;22:145. doi: 10.1186/s12880-022-00850-1. PubMed DOI PMC

Chrobok V, Mejzlík J, Šimáková E. Embryonální vývoj, fyziologie a vrozené vady zevního zvukovodu. Otorinolaryngol Foniatr. 2002;4:226–231.

Allanson BM, Low TH, Clark JR, Gupta R. Squamous Cell Carcinoma of the External Auditory Canal and Temporal Bone: An Update. Head Neck Pathol. 2018;12:407–418. doi: 10.1007/s12105-018-0908-4. PubMed DOI PMC

Hagisawa M, Yamasoba T, Ohashi K, Ishida T. A case of middle-ear myoepithelioma. Otolaryngol Head Neck Surg. 2006;135:967–968. doi: 10.1016/j.otohns.2005.05.016. PubMed DOI

Lee JW, Myung NH, Suh MW. Epithelial-myoepithelial carcinoma of external auditory canal evolving from pleomorphic adenoma. Korean J Audiol. 2012;16:148–151. doi: 10.7874/kja.2012.16.3.148. PubMed DOI PMC

Hornick JL, Fletcher CD. Cutaneous myoepithelioma: a clinicopathologic and immunohistochemical study of 14 cases. Hum Pathol. 2004;35:14–24. doi: 10.1016/j.humpath.2003.08.016. PubMed DOI

Michal M, Miettinen M. Myoepitheliomas of the skin and soft tissues. Report of 12 cases. Virchows Arch. 1999;434:393–400. doi: 10.1007/s004280050358. PubMed DOI

Savera AT, Sloman A, Huvos AG, Klimstra DS. Myoepithelial carcinoma of the salivary glands: a clinicopathologic study of 25 patients. Am J Surg Pathol. 2000;24:761–774. doi: 10.1097/00000478-200006000-00001. PubMed DOI

Pirsig W, Mudry A. Huschke's anterior external auditory canal foramen: art before medicine? Otol Neurotol. 2015;36:555–560. doi: 10.1097/MAO.0000000000000418. PubMed DOI

Lacout A, Marsot-Dupuch K, Smoker WR, Lasjaunias P. Foramen tympanicum, or foramen of Huschke: pathologic cases and anatomic CT study. AJNR Am J Neuroradiol. 2005;26:1317–1323. PubMed PMC

Koç A, Kaya S. Prevalence of foramen Huschke: evaluation of the association between mastoid pneumatization volume and the existence of foramen Huschke using cone beam computed tomography. Eur Arch Otorhinolaryngol. 2021;278:791–796. doi: 10.1007/s00405-020-06296-x. PubMed DOI

Pons M, Lutz JC, Sigaux N, Tavernier L, Graillon N, Louvrier A. Surgical reconstruction of the foramen tympanicum: What is known and how we do it. J Stomatol Oral Maxillofac Surg. 2020;121:545–549. doi: 10.1016/j.jormas.2020.04.005. PubMed DOI

van der Meer WL, van Tilburg M, Mitea C, Postma AA. A Persistent Foramen of Huschke: A Small Road to Misery in Necrotizing External Otitis. AJNR Am J Neuroradiol. 2019;40:1552–1556. PubMed PMC