Medical Excellence- Issue 1

Neuroendocrine Tumour of the Middle Ear: A Case Report Gautam Khaund 1 , Nayanjyoti Sarma 1 , Ronica Baruah 2 Case Report Our case is a 50-year-old male, who presented with pain in the left ear since 1 week at the Out-patient Department of Nightingale Hospital, Guwahati. One examination, an aural mass in the left external auditory canal protruding to the external auditory meatus was seen. Pure tone audiometry revealed pro- found mixed hearing loss in the affected side. HRCT temporal bone was advised and revealed low dense component in the left mastoid antrum, aditus and middle ear extending to the exter- nal auditory canal with the ossicles completely embedded within the low dense components. Routine haematological investiga- tions were normal and the patient was put for surgery. Modified Radical Mastoidectomy was performed. Granulation tissue at mastoid antrum, aditus and middle ear cavity and polyp at the external auditory canal was excised. The entire tissue was sent for histopathological examination. Histological examination of the excised tumor showed an epithelial neoplasm with predomi- nantly solid and trabecular pattern embedded in fibrovascular stroma. The tumour cells were uniform, have round nuclei with salt-and-pepper chromatin, eosinophilic cytoplasm. No evidence of mitosis or necrosis was noted. An immunohistochemical eval- uation showed strong positivity for Pan CK, synaptophysin and weak positivity for chromogranin. Ki67 index was low and S-100 was negative. Final diagnosis of middle ear adenoma with neu- roendocrine differentiation was made (Figs. 1, 2, 3). Neuroendocrine tumour of the middle ear is a rare entity. Here we present a case of a 50-year-old male who presented with a polyp in the left external auditory canal. Surgical excision followed by immunohistochemistry confirmed it to be a neuroen- docrine tumour. Keywords: Adenoma of middle ear, Carcinoid tumour, Adenocarcinoid, Adenomatoid tumour Discussion Neuroendocrine tumour are rare tumour arising from entero- chromaffin or Kulchitsky cells mostly found in gastrointestinal tract, lungs and bronchi [1]. The occurrence of NET in head and neck region is rare. When affected it mostly affects the larynx followed by middle ear [2, 3]. It accounts for less than 2% of all middle ear tumours. It mostly involved the middle ear cavi- ties engulfing the ossicles which may extend to mastoid antrum and auditory canal [4, 5]. The patient usually presents with unilateral hearing loss, tinnitus and occasional ear discharge [6]. Unlike in this case, the tumour usually remains confined to the middle ear cavity. It is usually fragmented, soft, rubbery and white to gray-tan. The tumour can be sub-divided into TC, AC, smCC, combined smCC with non-small cell carcinoma and those with neurological origins (paraganglioma) according to the 2005 WHO classification of head and neck tumours [7–10]. Immunohistochemistry shows tumour positive for Pan CK and synaptophysin. Differential diagnosis includes paraganglioma, ceruminous adenoma, metastatic adenocarcinoma and menin- gioma [6]. Surgical excision of the tumour through modified radical mastoidectomy is the treatment of choice [11]. Recurrences can be seen (up to 15%), especially if the ossicular chain is not removed [6]. No sufficient data exist regarding the role of chemo-radiation in middle ear adenoma. Conventional radio- therapy was used earlier either alone or in combination with surgery and chemotherapy. However, their efficacy is yet to be proved [12, 13]. In a review by Furuta et al. [14], it was proposed that radiation and chemotherapy can be performed as post-oper- ative adjuvant therapy when a complete resection is difficult and surgery is ineffective. Nayanjyoti Sarma (  ) nayansarma242@gmail.com 1 Nightingale Hospital, Guwahati 781006, India 2 Ekopath Metropolis Lab Services Pvt Ltd, Guwahati, India 18  |  Issue-1 MEDICAL EXCELLENCE