ANNALS OF IBADAN POSTGRADUATE MEDICINE
ADENOID CYSTIC CARCINOMA MISINTERPRETED AS ANTROCHOANAL
POLYP: A RARE PRESENTATION
R.K. Brar1 , J.N. Bharti1 , J.S. Nigam1 and S. Sehgal2
Adenoid cystic Carcnoma (ACC) is an uncommon malignant tumour accounting for <1% of all oral and maxillofacial tumors. However, in the sinonasal tract, ACC is the most common salivary gland tumor. The sinonasal ACC is asymptomatic initially or causes non-specific symptoms that are similar to those caused by inflammatory sinus disease and local neurological symptoms such as trigeminal neuralgia in advance stage due to perineural invasion by the tumour. We present a case of 35-year-old female who presented with complaints of nasal obstruction and headache. CT scans revealed an antrochoanal polyp without any bony involvement. The histopathological examination revealed unremarkable respiratory epithelium with underlying sheets and acini of small hyperchromatic cells with hyaline-like material in the lumina, confirming adenoid cystic carcinoma. The highlight of this case is that sinonasal polyps are not always inflammatory in origin, these can be neoplastic also.
Keywords: Sinonasal polyp; Nose; Maxillary sinus; PAS
Dr. J.S. Nigam
Department of Pathology,
Andaman & Nicobar Islands
Institute of Medical Sciences,
Andaman & Nicobar Islands,
Adenoid cystic carcinoma (ACC) is a rare, epithelial, slowly developing, malignant tumor with ductal, myoepithelial and basal cells differentiation.1,2 It constitutes about 10% to 15% of all salivary gland neoplasms and about 1% of all head and neck malignant tumors.1 The sinonasal malignancy comprises about 1–2% of all malignancies and ACC is the 3rd commonest sinonasal malignancy.3 Maxillary sinus is the most common site for sinonasal ACC (SNACC) followed by nasal cavity.3 Lateral nasal wall is the most common site in nose. The SNACC is asymptomatic initially or causes non-specific symptoms that are similar to those caused by inflammatory sinus disease and local neurological symptoms such as trigeminal neuralgia in advance stage due to perineural invasion by the tumour.3,4 We present a case of SNACC presented as antrochoanal polyp causing nasal obstruction and headache.
CASE: We present a case of a 35-year-old female who presented to the Department of Oto-rhinolaryngology with complaints of right sided nasal obstruction and headache for 1 month. There was worsening of nasal blockage for the last 15 days. On nasal anterior rhinoscopy, a glistening white soft tissue mass in the middle meatus and nasal cavity with a stalk rising from right maxillary ostium was noticed. Computed tomography (CT) scans showed a soft tissue lesion arising from the maxillary antrum and extension through the maxillary ostium into the nasal cavity between the middle turbinate and the lateral nasal wall without bone erosion. No cervical lymphadeno-pathy was seen. Radiological diagnosis of right benign antrochoanal polyp was given. The Functional endoscopic sinus surgery (FESS) for polypectomy was done. The tissue excised was received for histopathological examination. Multiple grey brown pieces of tissue were received for histopathological examination. The microscopic examination revealed unremarkable respiratory epithelium. Beneath the epithelium, there were sheets and acini of small hyperchromatic cells with hyaline-like material in the lumina and forming gland-like spaces. The cells had minimal amount of cytoplasm. Periodic acid Schiff (PAS) staining revealed magenta coloured hyaline material in the lumina, in the tumor area beneath respiratory epithelium (Figure 1). The final histopathological diagnosis of SNACC was given. The patient was transferred to higher centre for further management. Postoperative CT scan at the other centre revealed no reginal lymphadenopathy or distant metastasis. She did not report back to our centre after uneventful post-operative radiotherapy of 1 month duration and was lost to follow up.