Melanoma metastasis mimicking gastric cancer: a challenge that starts from diagnosis

The gastrointestinal tract is an uncommon site of metastasis in melanoma. However, when the primary melanoma cannot be found, the diagnosis of gastric melanoma by endoscopic biopsy is problematic mainly because some tumors are amelanotic and do not contain melanin granules detectable by microscopy. A 56-year-old Caucasian man with melanoma was referred to us following an initial histopathological diagnosis via gastroscopy of poorly differentiated primary gastric carcinoma. A computerized tomography (CT) scan showed metastatic disease and on the basis of this information we started palliative chemotherapy. However, the atypical presentation of the disease with subcutaneous metastases prompted us to make a more in-depth evaluation. Immunohistochemical evaluation modified the diagnosis to melanoma. After only one cycle of chemotherapy, treatment was changed to dabrafenib + trametinib, which was better tolerated and initially induced a partial response. The patient is currently in good clinical condition 20 months after diagnosis. Our case report highlights the difficulty in diagnosing melanoma of the gastrointestinal tract and indicates the need for pathologists and clinicians to consider such a possibility when they are faced with a diagnosis of poorly differentiated gastric cancer and unusual sites of metastasis.

Unusual Bladder Metastasis from a Primary Gastric Carcinoma: Two Case Reports and Review of Literature

Primary bladder cancer is a frequent malignancy in the urology field, whereas secondary bladder neoplasms from a distant organ are extremely rare. This paper aims to report two rare cases of a secondary tumor of the urinary bladder from a primary gastric tumor and to perform a literature review of similar reported cases in order to better characterize its clinicopathological features and diagnosis in effort to shed light on this rare condition. The final diagnosis of secondary adenocarcinoma was made histologically after transurethral biopsy or resection of the bladder lesion. In one case, the bladder metastasis was a synchronous metastasis, and in the second case, it occurred under chemotherapy five months after initial diagnosis with gastric adenocarcinoma. Secondary adenocarcinoma of the bladder is extremely rare but should be considered when evaluating a bladder lesion in a patient treated for gastric cancer or presenting with gastric symptoms.

Synchronous Hepatocellular Carcinoma in a Patient with Primary Gastric Cancer: An Exceptional Association

Hepatocellular carcinoma (HCC) is the most frequent type of liver cancer. Liver cirrhosis of any etiology is considered the main risk factor for the development of HCC. However, HCC in noncirrhotic livers remains an uncommon finding. The association of HCC with a primary gastric adenocarcinoma was described in the literature as part of a hepatoid adenocarcinoma which is a special type of primary gastric carcinoma characterized by histologic similarities to HCC with excessive production of α-fetoprotein. Herein, we report the case of a 50-year-old male patient, with no history of pre-existing liver disease, who was admitted due to epigastric pain and vomiting. He was diagnosed with HCC in noncirrhotic liver associated with primary gastric adenocarcinoma. To our knowledge, this is the first case report of synchronous HCC and gastric cancer with no hepatoid adenocarcinoma features in Tunisia.