Primary Gastric Melanoma: a Diagnostic Challenge

Metastatic primary gastric melanoma: a rare clinical presentation and a review of literature

Primary gastric melanoma is a rare clinical finding. It presents with upper gastrointestinal symptoms like abdominal pain, weight loss and melaena. It is often difficult to differentiate a primary gastric melanoma from primary cutaneous melanoma with gastric metastasis. Upper gastrointestinal endoscopy and biopsy of the lesion for histopathology and immunohistochemistry help to reach a definite diagnosis. We report a case of primary gastric melanoma with metastases to the liver and bone. The patient was treated with palliative radiotherapy, palliative chemotherapy and a bone-stabilising agent.

Mechanisms of JAK-STAT signaling pathway mediated by CXCL8 gene silencing on epithelial-mesenchymal transition of human cutaneous melanoma cells

Effect of CXCL8 gene silencing-mediated JAK-STAT signaling pathway on epithelial-mesenchymal transition (EMT) of human cutaneous melanoma cells was explored. Eighty patients with cutaneous melanoma were enrolled in the study. Cells were transfected accordingly and divided into five groups: The blank group (human cutaneous melanoma cells), NC group (human cutaneous melanoma cells + blank vector plasmid transfection), CXCL8 siRNA group (human cutaneous melanoma cells + CXCL8 silent expression vector plasmid transfection), AG490 group (human cutaneous melanoma cells + JAK-STAT signal pathway inhibitor transfection), CXCL8 siRNA + AG490 group (human cutaneous melanoma cells + JAK-STAT signaling pathway inhibitor + CXCL8 silent expression vector plasmid transfection). The expression levels of CXCL8, JAK2, STAT3, epithelial cadherin (E-cadherin), neurotrophic cadherin (N-cadherin) and vimentin in tissues and cells were detected by RT-qPCR and western blot analysis. CCK-8 and flow cytometry were used to detect cell proliferation and apoptosis. Compared with adjacent normal tissues, the expression of E-cadherin in human cutaneous melanoma tissues was significantly decreased, whereas the expression of CXCL8, JAK2, STAT3, vimentin and N-cadherin was significantly increased (P<0.05). Compared with the blank group, CXCL8 siRNA group and CXCL8 siRNA + AG490 group had significantly lower expression of CXCL8 (P<0.05). Compared with the blank group, the expression levels of JAK2, STAT3, vimentin and N-cadherin in CXCL8 siRNA group, AG490 group and CXCL8 siRNA + AG490 group were decreased, the expression of E-cadherin was increased, the cell proliferation ability was decreased and apoptosis was increased (P<0.05). Compared with CXCL8 siRNA group, the expression of JAK2, STAT3, vimentin and N-cadherin in CXCL8 siRNA + AG490 group were significantly decreased, the expression of E-cadherin was significantly increased, cell proliferation ability was decreased and apoptosis was increased (P<0.05). In conclusion, CXCL8 gene expression silencing may inhibit EMT and cell proliferation while promoting cell apoptosis of human cutaneous melanoma cells by inhibiting the activation of JAK-STAT signaling pathway.

Primary gastric melanoma in adult population: a systematic review of the literature

BACKGROUND

Primary gastric melanoma (PGM) is a rare malignant tumour of the stomach with poor prognosis. The aim of this systematic review was to assess the available literature on this entity and to highlight its biological behaviour and preferred treatment approach.

METHODS

PubMed and Cochrane bibliographical databases were independently searched (last search: 2 February 2020) by two investigators for articles reporting on PGM in the adult population.

RESULTS

Twenty-five studies met the inclusion criteria and concerned collectively 25 patients (18 males and seven females) with an age of 63.4 ± 8.97 years (mean ± standard deviation). Main symptoms included abdominal pain (64%), weight loss (48%) and hematemesis or melena (32%). The most frequent tumour location was the body of the stomach (54.2%). All tumours were surgically resected and the majority of the patients had a partial gastrectomy (52%). Median recurrence time was 5 months and 12% of patients reached 5-year survival landmark.

CONCLUSION

PGM is a rare disease characterized by an aggressive malignant behaviour. Its differential diagnosis from a metastatic lesion is crucial. A prompt diagnosis and therapeutic approach are needed. Further studies are required to elucidate the optimal management of this clinical entity.