|Year : 2014 | Volume
| Issue : 2 | Page : 416-418
Primary mucosal malignant melanoma of nasopharynx: A rare case report
Department of Pathology, Indira Gandhi Medical College, Shimla, India
|Date of Web Publication||14-Jul-2014|
12-A, Type V Quarters, IAS Colony, Kasumpti, Shimla, HP
Source of Support: None, Conflict of Interest: None
Mucosal malignant melanoma (MMM) of the nasopharynx is extremely rare. We report a case of MMM of the nasopharynx in a 56-year-old male patient presenting with a polypoidal mass in the nasopharynx. It was increasing gradually and obstructing breathing. Computed tomography scan was suggestive of a malignant neoplasm in the nasopharynx. A biopsy of the lesion was done with a clinical suspicion of carcinoma. Microscopy revealed features suggestive of malignant melanoma with focal melanin pigmentation. Subsequently, wide local excision was done.
Keywords: Primary, malignant melanoma, mucosal, nasopharynx
|How to cite this article:|
Mardi K. Primary mucosal malignant melanoma of nasopharynx: A rare case report. J Can Res Ther 2014;10:416-8
| > Introduction|| |
Malignant melanomas are tumors arising from melanocytes which are neuroectodermally derived cells located in the basal layers of skin, skin adnexas, and smucosa of some areas. Common sites for melanomas are head, neck, and the lower extremities as they are exposed to sunlight, which is one of the important predisposing factors. Less commonly, they occur in the oral and genital mucosa, nail beds, conjunctiva, orbit, esophagus, nasal mucosa or nasopharynx, vagina, and leptomeninges. In this paper we have described a rare case of malignant melanoma of the nasopharynx extending to the nose.
| > Case report|| |
A 56-year-old male patient came to us with the complaints of swelling of the nose, nasal blockage, and epistaxis for 2 months. He noticed a small swelling of 1 cm diameter on the left side of the nose 2 months back. The symptoms increased rapidly. On clinical examination, a huge swelling was noticed on the left side of the nose, measuring 5 × 4 cm. There was a fleshy, bluish red, friable, non-tender mass in the left nostril, which was completely blocking the nasal passage and bled slightly on touch. The left ala was stretched and dilated blood vessels were seen over it. The septum was markedly deviated to the right by the mass. On posterior rhinoscopy, the mass was found to be occupying the nasopharynx. The throat, ears, and larynx were normal on examination.
Computed tomography (CT) scan showed an invasive destructive mass in the nasopharynx extending into the left nasal cavity [Figure 1]. A provisional diagnosis of carcinoma of nasopharynx with extension into the left nostril was made. The patient was operated and tumor was excised. The melanoma was polypoidal and capsulated which ruptured during removal, and hence it was removed in pieces. The final attachment was broad based and was found on the lateral wall of nasopharynx, anterior to the Eustachian tube orifice, extending to the posterior end of the middle turbinate. The left maxillary antrum was inspected by Caldwell-Luc approach and was normal. Anterior and posterior nasal packing was done. Supraomohyoid block dissection was done on the left side and it was found that the lymph nodes were transformed into a mass, which was blue in color and filled with thick bluish fluid. Radiotherapy was given following complete wound healing. The patient was followed for a period of 2½ years and there was no recurrence.
|Figure 1: CT scan revealing a destructive mass in the left nasopharynx, extending into left nostril|
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After removal of the tumor, the gross examination revealed multiple bits of size 2.5 × 2× 1 cm, totally aggregating to form 7 × 5 cm mass. It was firm and dark blue to black in color.
On microscopic examination, the tumor showed extensive areas of necrosis with sheets and nests of pleomorphic tumor cells beneath the pseudostratified columnar ciliated epithelial lining of nasopharynx [Figure 2]. Individual tumor cells showed pleomorphic hyperchromatic nucleus with prominent nucleolus and moderate to abundant eosinophilic cytoplasm. Focal areas showed abundant melanin pigment deposition in the tumor cells [Figure 3].
|Figure 2: Photomicrograph showing the tumor beneath the nasopharyngeal mucosa (H and E, ×20)|
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Immunohistochemically, the tumor cells showed positivity for HMB-45.Thus, the final diagnosis of primary mucosal malignant melanoma (MMM) of nasopharynx was made.
|Figure 3: Higher magnification showing pleomorphic tumor cells with abundant melanin production (H and E, ×40)|
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| > Discussion|| |
Primary MMM of head and neck accounts for 1.3% of malignant melanomas,  and of these, 0.5% are located in sinonasal tract.  Primary MMM is extremely rare.  According to Batsakis et al.,  of all the mucosal melanomas of head and neck, 56% occur in upper respiratory tract and only 0.6% cases occur in the nasopharynx.
The tumor occurs between 50 and 70 years of age  and is slightly more common in males than females, although age and sex do not affect the prognosis. , Because of its rarity, mucosal melanoma is poorly understood, characterized, and studied.
Mucosal melanomas show far more aggressive behavior as compared to skin melanomas, and these tumors are more inclined to metastasize into regional and distant sites or recur locally, regionally, or in distant locations, resulting in a high rate of cause-specific death. Rich submucosal vasculature and lymphatics account for their aggressive behavior.
Small, round cell neoplasms of the sinonasal tract often generate considerable diagnostic difficulty. Differential diagnoses of such undifferentiated small blue cell tumors of sinonasal tract include olfactory neuroblastoma, sinonasal undifferentiated neuroendocrine carcinoma, and Ewing's sarcoma/peripheral neuroectodermal tumor (PNET) and rhabdomyosarcoma.
Immunohistochemistry remains the diagnostic gold standard. HMB-45 expression seems to be 100% specific for the diagnosis of melanoma. Melan-A is slightly less specific. Morris et al.  analyzed the results of immunohistochemistry in primary mucosal melanoma of head and neck and came to the conclusion that PNL-2 is a highly sensitive marker for mucosal melanoma, likely superior to Melan-A and Microphthalmia-associated transcription factor (MITF) and comparable to HMB-45, with specificity superior to S-100. Therefore, PNL-2 is an important adjunctive marker in the immunohistochemical evaluation of primary mucosal melanomas.  Yu et al.  studied the expression of three melanocytic markers, HMB-45, S-100, and Melan-A, in primary oral and nasal mucosal melanomas. Their results indicated that both HMB-45 and S-100 show a high positive rate and labeling index in mucosal melanomas, and therefore may be good markers for immunohistochemical diagnosis of primary oral and nasal mucosal melanomas.
Various methods of therapy, including surgery, irradiation alone, irradiation with surgery, and chemotherapy, have been used in treating malignant melanoma of the nose. Surgical exclusion is the best treatment, as malignant melanoma is considered to be radioresistant. Different chemotherapeutic regimens have been tried which include vinca alkaloids, alkylating agents, antimetabolites, levamisole, dimethyl trizeno imidazole carboxamide (DTIC), and dactinomycin, but all with unsatisfactory results. 
Primary mucosal melanomas show far more aggressive behavior relative to skin melanomas, with early local recurrences, extensions, and frequent metastasis to lymph nodes and viscera, making them one of the most dangerous forms of nasal and paranasal sinus tumors. The incidence of regional lymph node metastasis on admission is approximately 5-15%.  The submandibular lymph nodes are most commonly involved.
The overall prognosis is grim for MMM of the sinonasal tract; the 5-year survival ranges from 17 to 46%.  There is no time period after which a patient with MMM should be considered as cured.
| > References|| |
|1.||Chang AE, Karnell LH, Menck HR. The National Cancer Data Base report on cutaneous and noncutaneous melanoma: A summary of 84,836 cases from the past decade. The American College of Surgeons Commission on Cancer and the American Cancer Society. Cancer 1998;83:1664-78. |
|2.||Gallotti M, Gencarelli G, Lancella A, Perinti A. [Primary malignant melanoma of the nasal mucosa with orbital involvement. Case report]. Acta Otorhinolaryngol Ital 2002;22:248-51. |
|3.||Grewal DS, Lele SY, Mallya SV, Baser B, Bahal NK, Rege JD. Malignant melanoma of nasopharynx extending to the nose with metastasis in the neck. J Postgrad Med 1994;40:31-3. |
|4.||Batsakis JG, Regezi JA, Solomon AR, Rice DH. The pathology of head and neck tumors: Mucosal melanomas, part 13. Head Neck Surg 1982;4:404-18. |
|5.||Pantazopoulos PE. Primary malignant melanoma of the nasal fossa. Ann Otol Rhinol Laryngol 1965;74:604-10. |
|6.||Bothale KA, Maimoon SA, Patrikar AD, Mahore SD. Mucosal malignant melanoma of the nasal cavity. Indian J Cancer 2009;46:67-70. |
|7.||Morris LG, Wen YH, Nonaka D, DeLacure MD, Kutler DI, Huan Y, et al. PNL-2 Melanocytic marker in immuno-histochemical evaluation of primary mucosal melanoma of the head and neck. Head Neck 2008;30:771-5. |
|8.||Yu CH, Chen HH, Liu CM, Jeng YM, Wang JT, Wang YP, et al. HMB-45 may be a more sensitive maker than S-100 or Melan-A for immunohistochemical diagnosis of primary oral and nasal mucosal melanomas. J Oral Pathol Med 2005;34:540-5. |
|9.||Gasparyan A, Amiri F, Safdieh J, Reid V, Cirincione E, Shah D. Malignant mucosal melanoma of the paranasal sinuses: Two case presentations. World J Clin Oncol 2011;2:344-7. |
|10.||Dwivedi R, Samanta N, Agarwal N. Primary malignant melanoma of the nasal cavity and paranasal sinuses: A rare cause of epistaxis in the elderly. Internet J Head Neck Surg 2007;2:1. |
[Figure 1], [Figure 2], [Figure 3]