CASE 16984 Published on 26.08.2020

Primary malignant melanoma of the oesophagus: a case report.

Section

Chest imaging

Case Type

Clinical Cases

Authors

Dafouz, Alan Iván MD; Del Valle, Juan Bautista MD; Avila , Sergio MD; Diaz, Facundo Nahuel MD; Ennis, María Lucila MD; Pietrani, Marcelo MD

Hospital Italiano de Buenos Aires, Tte. Gral. Juan Domingo Perón 4190, C.A.B.A., Código Postal: C1199ABB, Argentina

Patient

80 years, male

Categories
Area of Interest Nuclear medicine, Oncology ; Imaging Technique CT-Enterography
Clinical History

An 80-year-old male patient consulted his primary care physician after presenting progressive dysphagia to solids and unquantified weight loss. Previous medical history accounts for a hyperplastic colorectal polyp.

He was referred for initial diagnostic workup. Upper gastrointestinal endoscopy was requested, followed by contrast-enhanced 18F-FDG pneumo PET/CT.

Imaging Findings

Upper gastrointestinal endoscopy revealed a brownish oesophageal lesion that occluded 70% of the oesophagal lumen, located 25cms from the incisors (fig. 1). It was identified, by biopsy, as melanoma.

Contrast-enhanced 18F-FDG pneumo PET/CT showed a hypermetabolic mass of 44x33x100 mm. (mean SUV: 6.4), protruding into the oesphageal lumen (fig. 2). Other hypermetabolic findings (metastases) included mediastinal lymph nodes, right acromion, transverse process of T11 and pedicle of L5 vertebrae. Increased FDG uptake at the left acromioclavicular joint was consistent with degenerative joint disease (fig. 3). This study was executed placing, transnasally, a Foley catheter (below the cricopharyngeal muscle). Distension was achieved with a CO2 pump and intravenous hyoscine N-butylbromide administration.

Diagnosis of primary malignant melanoma of the oesophagus was made since no other pigmented lesions were observed (skin, eyes, and anus). After diagnosis was established, he returned his home province for treatment planning. This patient was lost to follow-up.

Discussion

Primary malignant melanoma of the oesophagus (PMMO) is a rare neoplasm and its reported prevalence accounts for up to 0.5% of all oesophageal malignancies. It is more prevalent during the 6th and 7th decades of life with a male to female ratio of 2:1. Most PMMO are commonly located in the middle or lower oesophagus, probably due to the melanocytes concentrated in this area. While primary melanoma of the gastrointestinal tract is extremely rare, cutaneous melanoma can metastasize to the gastrointestinal tract. PMMO diagnosis can be accepted in patients with no history of melanoma and absence of melanoma involving other frequent sites (skin, eyes, anus, or vagina) [1].

Major risk factors have not been defined yet. Still melanosis, a benign condition, has been reported as a predisposing factor [2] .

Most common symptoms include dysphagia and weight loss [3]. Symptoms are usually present for 3 months [2,4]. Gross specimens are usually polypoid shaped, vary in size and colour (ranging from black to white for amelanotic forms), and are covered by normal mucosa [4]. Immunohistochemical staining is of paramount importance, positive HMB-45 and S-100 protein allows accurate diagnosis [1-4].

PMMO is usually diagnosed at advanced stages; metastases are found in up to 40-50% of the cases at the time of diagnosis [1-4]. Commonly involved sites are paraesophageal, supraclavicular and celiac lymph nodes, brain, liver, lungs, and bones [1,2,4]. In this regard, Caldwell et. al mentioned the presence of regional nodal metastases in 66% of cases [5].

The overall prognosis for PMMO is poor with estimated survival of 10-13 months at the time of the diagnosis [1-4].

Imaging plays a central role in pretreatment staging and therapeutic strategy planning in cancer patients. PET CT has revolutionised medical diagnosis owing to its high sensitivity for malignant lesions. Pneumo PET CT, an emerging useful tool, provides information about the oesophageal and gastric walls as well as the benefits of functional imaging (evaluation of distant metastatic disease) in a “one-shot” study [6].

Treatment strategy has not been yet established on account of debatable evidence and number of reported cases. While oesophagectomy remains the backbone of PMMO treatment, it is not always possible and is related to high postoperative morbidity and mortality. The role of radiotherapy, chemotherapy, and immunotherapy is still unclear but may play a part in palliative treatment [7,8].

Differential Diagnosis List
Primary malignant melanoma of the oesophagus
Squamous cell carcinoma
Sarcoma
Oat cell carcinoma
Metastasis
Final Diagnosis
Primary malignant melanoma of the oesophagus
Case information
URL: https://www.eurorad.org/case/16984
ISSN: 1563-4086
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