Chest imagingCase Type
Dafouz, Alan Iván MD; Del Valle, Juan Bautista MD; Avila , Sergio MD; Diaz, Facundo Nahuel MD; Ennis, María Lucila MD; Pietrani, Marcelo MDPatient
80 years, male
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.
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.
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) .
Major risk factors have not been defined yet. Still melanosis, a benign condition, has been reported as a predisposing factor  .
Most common symptoms include dysphagia and weight loss . 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 . 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 .
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 .
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].
 Jora, Charu, et al. "Primary malignant melanoma of the esophagus." Indian journal of nuclear medicine: IJNM: the official journal of the Society of Nuclear Medicine, India 30.2 (2015): 162.
 Machado, Joana, et al. "Primary malignant melanoma of the esophagus: a case report." World Journal of Gastroenterology: WJG 17.42 (2011): 4734.
 Butte, Jean M., et al. "Melanoma primario del esófago tratado con esofagectomía: Casos clínicos." Revista médica de Chile 138.1 (2010): 77-81. (PMID: 20361155)
 Volpin, E., et al. "Primary malignant melanoma of the esophagus: a case report and review of the literature." Diseases of the Esophagus 15.3 (2002): 244-249. (PMID: 12444999)
 Caldwell, C. B., M. S. Bains, and M. Burt. "Unusual malignant neoplasms of the esophagus. Oat cell carcinoma, melanoma, and sarcoma." The Journal of thoracic and cardiovascular surgery101.1(1991):100-107.(PMID: 1702494)
 Diaz, Facundo N., et al. "Pneumo-PET-CT: Initial Results of This Novel Technique on the Evaluation of Esophageal and Gastric Tumors with Anatomic-Surgical Correlation." Gastroenterology research and practice 2019 (2019). (PMID: 30867663)
 Gao, S. et al. Characteristics and Surgical Outcomes for Primary Malignant Melanoma of the Esophagus. Sci. Rep. 6, 23804; doi: 10.1038/srep23804 (2016). (PMID: 27033424)
 Morita, Flávio Hiroshi Ananias, et al. "Primary malignant melanoma of the esophagus: a rare and aggressive disease." World journal of surgical oncology 11.1 (2013): 210. (PMID: 23972096)
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