Endoscopic Resection of a Massive Pleomorphic Adenoma of the Nasal Septum

Abstract

Pleomorphic adenoma is a benign tumor that commonly arises from the major salivary glands, such as the parotid and submandibular glands. However, they rarely originate from the nasal cavity. Herein, we describe the case of a 49-year-old woman who presented with nasal obstruction. Preoperative evaluation revealed a giant pleomorphic adenoma attached to the nasal septum. Transnasal endoscopic removal was successfully performed using a specimen retrieval bag. We performed an endoscopic complete en-bloc resection of a large pleomorphic adenoma in the nasal cavity, using a specimen retrieval bag. There were no complications seen, no local recurrences after 2 years of follow-up, and the patient satisfaction was high. We therefore recommend that this technique of using specimen retrieval bags can be favorably utilized for endoscopic removal of large nasal tumors like pleomorphic adenoma.

Introduction

Pleomorphic adenomas are the most common benign salivary gland tumors. They arise from the major salivary glands, ¹ but in some cases arise they from the minor salivary glands, such as those in the nasal cavity. ² The incidence of tumors originating from the nasal cavity was reportedly higher than that of the major salivary glands in young women. ³

The gold standard treatment for pleomorphic adenoma is complete surgical resection. In this report, we present a case of successful endoscopic en bloc resection of a large pleomorphic adenoma involving the nasal septum using a specimen retrieval bag.

Case Report

A 49-year-old woman with a 1-month history of bilateral severe nasal obstruction and left epiphora was referred to our department. Nasal endoscopic examination revealed a smooth, pale-yellow mass arising from the nasal septum in the left nasal cavity. Due to the expansion of the mass, the septum was markedly deviated to the right. Physical examination revealed neither enlarged cervical lymph nodes nor abnormal findings in the oral cavity or pharynx.

Computed tomography (CT) showed a soft tissue density mass, measuring approximately 40 mm × 40 mm in diameter, in the left nasal cavity. On contrast CT, the tumor exhibited a heterogenous contrast effect. The tumor expanded the medial maxillary wall and extended posteriorly into the choana. Magnetic resonance imaging revealed a heterogeneously enhancing mass on gadolinium-enhanced T1-weighted imaging without orbital or skull base invasion (Figure 1). A biopsy confirmed the diagnosis of a pleomorphic adenoma. Consequently, endonasal endoscopic surgery was performed.

Figure 1.

Magnetic resonance imaging with gadolinium contrast shows nonuniform enhancement. (A) Coronal section. (B) Sagittal section.

The base of the tumor was attached to the left nasal septum. The mass was resected with a 5-mm safety margin, including a section of the septum cartilage (Figure 2A). The resected tumor was too large to be extracted from the anterior or posterior nostrils. Hence, we housed the tumor in a specimen retrieval bag. The tumor inside the bag was then crushed and morcellated, and the bag was removed from the anterior nostril (Figure 2B). The postoperative course was uneventful.

Figure 2.

Intraoperative endoscopic findings. (A) Base of the tumor is located posterior to the septal cartilage. (B) The tumor is enclosed in the specimen retrieval bag. (C) The tumor is removed from anterior nostril. The bag is intact after removal.

Pathological examination revealed epithelial and myoepithelial components in the background of a cartilage-like stromal component. Pathological analysis revealed a typical pleomorphic adenoma with no evidence of malignancy. There were no signs of local recurrence in the patient during the 2-year follow-up period.

Discussion

Pleomorphic adenomas, a common tumor of the major salivary glands, are rarely present in the oral cavity, pharynx, larynx, buccal mucosa, trachea, and nasal cavity. ^{3 -5} Bergman reported 204 pleomorphic adenomas originating from the large salivary glands. Only 16% were from the minor salivary glands, with only one case from the nasal cavity. ⁶ Nasal pleomorphic adenomas originate from the nasal salivary glands, predominantly located in the nasal septum. ⁷ Therefore, nasal pleomorphic adenomas most often arise from the nasal septum. ³

The chief presenting symptom of an intranasal pleomorphic adenoma is nasal obstruction. ⁸ Symptoms are detected early, even in smaller tumors. ⁸ Large tumors, as seen in our case, are rare.

The diagnosis of pleomorphic adenoma was confirmed by histopathological examination, which consisted of 3 essential elements, including epithelial cells, myoepithelial cells, and mesenchymal/stromal elements. Pleomorphic adenomas of the nasal septum have fewer stromal components than major salivary gland tumors. ³ The dissemination of the stromal component of pleomorphic adenoma cause metastasis and recurrence. ³ Pleomorphic adenomas of the nasal septum have lower recurrence rates than those of the major salivary glands. ³

The definitive treatment for pleomorphic adenoma of the nasal septum is total excision. Pleomorphic adenomas respond poorly to chemotherapy and radiotherapy. Furthermore, radiation may induce the malignant transformation of tumors. ⁹ With the advancements in minimally invasive surgeries, endoscopic surgery has become the preferred choice for nasal pathologies. Kandiah et al reported a case wherein nasoendoscopic excision of a large pleomorphic adenoma of the nasal septum reduced intraoperative blood loss and postoperative pain. ² However, it was extracted in pieces due to the difficulty of removing the tumor from the nostrils. Piecemeal resection of large tumors should be avoided to lessen the risk of recurrence. ⁸ Enucleation reportedly increased the recurrence rates for pleomorphic adenomas of the major salivary glands. ¹⁰ Despite the pathological features of nasal pleomorphic adenomas, a piecemeal resection should be avoided. Large tumors have been removed by making an external incision or through an oral cavity incision.

To our knowledge, this was the first case of en bloc excision of a pleomorphic adenoma in the nasal cavity using a specimen retrieval bag. Gynecologic laparoscopic surgeries for large benign tumors, such as myomas, commonly utilize specimen retrieval bags to morcellate the tumor. ¹¹ Laparoscopic uterine myomectomy is similar to endoscopic resection of intranasal pleomorphic adenomas, wherein large myomas are extracted through a small hole. In addition, dissemination of the tumor components can cause recurrence (parasitic myoma). ¹² Hence, this technique of covering the tumor in a bag, fragmenting it into smaller pieces (morcellation), and removing it, has been performed. In this case, a similar procedure, wherein the tumor was completely enveloped in the end bag, crushed, and then removed from the anterior nostril, was performed.

Some contentious aspects of this technique involve crushing. In gynecologic literature, extensive discussions regarding the advantages and disadvantages of this method have been conducted. Some reports have concluded that myomas are disseminated using this technique. ¹³ Another study reported that unsuspicious malignant uterine lesions were morcellated. ¹⁴ However, this method is beneficial for large tumors. Improvements in endoscopic technology and equipment have overcome these limitations. Cohen et al examined the risks of leakage and tissue dissemination. They evaluated various tissue extraction techniques in vitro to observe content leakage. They concluded that none of the techniques resulted in leakage or tissue dissemination. ¹⁵ In our case, no evidence of malignancy was found on histopathological examination, and there were no signs of local recurrence over the 2 years of follow-up. Malignancy should be ruled out by imaging and biopsy before surgery. Although further trials involving multiple cases are needed, this method has several advantages. The procedure is minimally invasive with a decent postoperative recovery, and the patient satisfaction is high because it does not require an external incision.

Conclusion

We performed an endoscopic complete en bloc resection of a large pleomorphic adenoma in the nasal cavity using a specimen retrieval bag. Neither complications nor local recurrences were observed after 2 years of follow-up, and the patient was highly satisfied. Therefore, we recommend using specimen retrieval bags for endoscopic removal of large nasal tumors, such as pleomorphic adenoma.