Abstract
Background
Mucosal melanoma of the palatine tonsil is extremely rare. Due to its poor prognosis, primary tonsillar melanoma requires prompt recognition and treatment.
Methods
A 62-year-old female presented with a deeply pigmented and exophytic lesion in the left tonsillar fossa. The patient underwent a partial pharyngectomy through a midline labio-mandibulotomy approach along with a left level I–V neck dissection. Reconstruction with a left radial forearm free flap and a pharyngeal constrictor advancement pharyngoplasty was performed.
Results
The patient remains free of disease at eight months after adjuvant proton therapy and eleven months after surgery. To our knowledge, less than thirty cases have been either reported or referenced in the literature since the early 1900′s. This report is the first in English literature to compile all reported cases of primary tonsillar melanoma.
Conclusion
Currently, evidence suggests that mucosal melanoma in the palatine tonsil should be treated in the same fashion as other head and neck mucosal melanomas, mindful of the high rates at which locoregional and distant metastases occur.
1
Introduction
Although more than half of all primary mucosal melanomas arise in the head and neck, these cases only account for 1.3% of all melanomas and less than 10% of all head and neck melanomas reported in the United States . The most common sites for mucosal melanoma in the head and neck region, in descending frequency, are the nose and paranasal sinuses, oral cavity, pharynx, and larynx . The oropharynx is an exceptionally rare site of origin for mucosal melanoma . The average age of patients diagnosed with mucosal melanoma of the pharynx or oral cavity is 61–65 years with rates more than twice as high in men than women . Because this disease has a very poor prognosis, prompt recognition and treatment are paramount. Herein we present an unusual case of primary mucosal melanoma arising in the palatine tonsil.
2
Materials & methods
A 62-year-old female presented after noticing bleeding from a left tonsillar lesion while brushing her teeth. She had a deeply pigmented, exophytic lesion in the left tonsillar fossa measuring 3 cm by 4 cm. There were no satellite lesions elsewhere in the oral cavity and pharynx, and no clinical or radiographic evidence of cervical adenopathy. The remainder of her physical examination, including cranial nerve examination, was within normal limits. The patient had a history of paroxysmal supraventricular tachycardia, hypertension, hyperlipidemia, and underwent a tonsillectomy as a child. She underwent a biopsy of the left tonsillar lesion under local anesthesia, which revealed malignant melanoma replacing tonsillar stroma. Magnetic resonance imaging (MRI) showed a left tonsillar mass extending to the soft palate without invasion of the mandible or masticator space. A PET/CT demonstrated a hypermetabolic lesion in the tonsil with an SUV of MAX 3.0, and did not exhibit regional or distant metastases. A brain MRI was normal.
The patient underwent a partial pharyngectomy ( Fig. 1 ) through a midline labio-mandibulotomy approach, along with a left level I–V selective neck dissection. Reconstruction with a left radial forearm free flap and a pharyngeal constrictor advancement pharyngoplasty was performed ( Figs. 2 and 3 ).
2
Materials & methods
A 62-year-old female presented after noticing bleeding from a left tonsillar lesion while brushing her teeth. She had a deeply pigmented, exophytic lesion in the left tonsillar fossa measuring 3 cm by 4 cm. There were no satellite lesions elsewhere in the oral cavity and pharynx, and no clinical or radiographic evidence of cervical adenopathy. The remainder of her physical examination, including cranial nerve examination, was within normal limits. The patient had a history of paroxysmal supraventricular tachycardia, hypertension, hyperlipidemia, and underwent a tonsillectomy as a child. She underwent a biopsy of the left tonsillar lesion under local anesthesia, which revealed malignant melanoma replacing tonsillar stroma. Magnetic resonance imaging (MRI) showed a left tonsillar mass extending to the soft palate without invasion of the mandible or masticator space. A PET/CT demonstrated a hypermetabolic lesion in the tonsil with an SUV of MAX 3.0, and did not exhibit regional or distant metastases. A brain MRI was normal.
The patient underwent a partial pharyngectomy ( Fig. 1 ) through a midline labio-mandibulotomy approach, along with a left level I–V selective neck dissection. Reconstruction with a left radial forearm free flap and a pharyngeal constrictor advancement pharyngoplasty was performed ( Figs. 2 and 3 ).
3
Results
The microscopic evaluation of the surgical specimen showed a subepithelial neoplastic cellular proliferation admixed with residual tonsillar and minor salivary gland tissue, which measured 2.8 cm in greatest dimension. The neoplasm was predominately characterized by a diffuse growth with areas showing a peritheliomatous pattern. The tumor cells showed epithelioid morphology with scant to moderate eosinophilic cytoplasm, round to oval pleomorphic nuclei and prominent nucleoli. Increased mitotic figures including atypical mitoses and melanin pigment were easily identified. The overlying squamous epithelium was intact, and no intraepithelial melanocytic proliferation was seen. Immunohistochemical stains showed that the tumor cells were positive for MelanA and S100. The overall findings were those of a malignant melanoma. The surgical resection margins were negative and no perineural or vascular invasion was identified; however, metastatic disease was present in one of fourteen cervical lymph nodes.
After successful DNA extraction from paraffin embedded tissue, the melanoma was subjected to molecular analysis using a 50-gene targeted next-generation sequencing platform (Ampliseq Cancer HotSpot panel V2, Life Technologies, NY). Somatic mutations in NRAS c.35G > A (p.Gly12Asp, p.G12D) and RB1 c.1735C > T (p.Arg579*. p.R579*) were identified. The tumor was staged as pT4aN1M0 using the AJCC mmTNM staging system.
The patient’s post-operative course was complicated by a pharyngocutaneous fistula which required her return to the operating room for a pectoralis major muscle flap to provide coverage of the neck. She underwent adjuvant proton therapy at a dose of 30.05 Gy. She remains free of disease at eight months after radiation treatment and eleven months after surgery, and is tolerating a normal diet. The patient has elected to enter a phase 2, randomized, open label, two-arm immunotherapy clinical trial.
4
Discussion
Primary mucosal melanomas in the head and neck region behave more aggressively than cutaneous melanomas and occur at a much lower rate . Because the majority of oropharyngeal cases are squamous cell carcinomas, melanomas only account for less than 5% of oropharyngeal malignancies . Hence, there is a paucity of information on primary tonsillar melanoma and, to our knowledge, twenty-six cases have been either directly reported or referenced in the literature since 1910 . We are the first to compile all reported cases of primary tonsillar melanoma, including those reported in languages beside English. Two of these papers reported five cases within the United States . We have provided a table of the reported cases for which sufficient clinical information was available through an extensive literature review. ( Table 1 ) Six cases could only be found as references . Twelve cases were excluded from the table, as they were not reported with sufficient information on the patient’s clinical course.
| Author/year | Age/sex | Symptoms | Tumor description | Metastases | Primary treatment | Outcomes |
|---|---|---|---|---|---|---|
| Centeno M et al./2014 (Spain) | 40/M | NA | 7.6 cm, grayish-brown, poorly defined margins, ulcerated, infiltrated tongue muscle, Melan-A +, S 100 +, HMB 45 + | Regional nodes | Pharyngectomy, left cervical radical lymphadenectomy | NA |
| Baderca F et al./2014 (Romania) | 53/M | Tonsillar bleeding, odynophagia, jaundice, melena, anemia | Around 3 cm, colorless | Regional nodes, gastric and ileal melanoma metastases | Right tonsillectomy | NA |
| Gorsky M et al./1998 (Israel) a | 86/M | Sore throat for 6 months | 4 cm, pigmented, fungiform mass | NA | Radiation | NA |
| Xavier R et al./1996 (Portugal) | 75/F | Odynophagia, progressive high dysphagia, sialorrhoea | 8 mm, pigmented, necrosis, ulceration, HMB 45 + | None | Tonsillectomy, adjuvant radiation, drug therapy (Tamoxifen) | 6 months post-treatment free of disease |
| Jung YK et al./1996 (South Korea) b | 36/M | Sore throat for 3 years | Focally dark, S 100 +, HMB 45 + | None | Tonsillectomy | 1 year post-treatment free of disease |
| Walsted A et al./1989 (Denmark) | 38/F | Presented with post-partum pneumonia | 0.85 mm thick, dark pigmented area extending to plica palatopharyngea, lighter pigmentation of the soft palate | None | Tonsillectomy, resection of soft palate and constrictor muscles, adjuvant radiotherapy | Persistent ulceration. 1 year post-treatment patient died of aspiration due to a massive hemorrhage from the mouth |
| Krishna Rao TV et al./1977 (India) | 40/M | Dysphagia, change in the tone of voice, foreign body sensation in the throat for one year | 2 × 1.5 cm, black, immobile, fleshy, cauliflower-like mass invading anterior faucial pillar, extending but not invading the uvula. Nontender and did not bleed to touch. | None | Resection of tonsillar fossa | NA |
| Mesara BW et al./1968 (USA) b | 52/M | Sore throat for 6 months | Pigmented lesion | Lung | Phenylalamine perfusion | Succumbed to disease 6 months post-treatment |
| Coassolo M/1960 (Italy) | 49/M | NA | NA | Regional nodes | Radiation therapy, lateral neck dissection | Succumbed 9 months post-initial presentation to neoplastic cachexia with symptoms of diffuse melanosis, abdominal colic, and melanuria |
| Huet P. C et al./1958 (France) b | 59/M | Sensation of foreign body in mouth for 1 month | Not firm, non-pigmented | Liver | Radiation therapy | Succumbed to disease 6 months post-treatment |
| Svane-Knudsen V et al./1957 (Denmark) b | 48/F | Light pain in left side of neck for approximately 10 days | Bluish-black color, sharply delineated, not ulcerated | None | Radiation therapy, followed by radical tonsillectomy, adjuvant radiation therapy | Patient had no evidence of disease 11 months post-treatment |
| Huet P·C et al./1953 (France) | 55/M | Swelling of the right neck for 6 months | Uniformed slate-color, infiltration of the entire tonsil with no induration | None | Surgical resection | No recurrent disease (duration of follow up unknown) |
| Howarth W/1941 (England) b | NA/M | NA | Extensive pigmentation of palate for two years. Eventually raised, lobulated, hard and rubbery mass took up most of the tonsil | NA | Radiation therapy with no effect, excision of main mass | 1 year post-treatment a left tonsillar mass was excised and diffuse pigmentation of palate remained with no recurrence |
| Schibler W et al./1934 (Germany) | 59/M | Dysphagia and faint pain radiating towards the right ear | 3–4 cm, soft, lobulated, greyish-red, some areas of heavy pigmentation, friable | Palate, lymph nodes, most internal organs | NA | Succumbed to disease 9 months post-treatment |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
