A first case report of rare synchronous double cancers: malignant cutaneous melanoma and gastrointestinal stromal tumor

A 55-year-old man presented with periumbilical pain associated with the development of brownish discoloration near the umbilicus. The condition started 6 months before seeking medical attention. The pain increased particularly at the site of the brownish lesion and became more intense when the patient touched the site of the lesion. The gradual increase in pain severity as well as the noticeable changes of the skin lesion (the brownish discoloration became harder, larger and darker in hue) led the patient to seek medical advice. The patient has not been exposed to prominent risk factors being a non-smoker, since he works in a risk-free environment as a mechatronic engineer. Unfortunately, he has a positive family history of malignancies, which was unfavorable with his delayed diagnosis. His father died at the age of 72 due to lung cancer and his mother is a survivor of basal cell carcinoma of the nasomaxillary region.
Upon skin examination, the non-ulcerated skin lesion has been revealed. Melanoma malignum cutis has been identified after performing a preoperative dermatoscopy (Figure 1). The tumor was subsequently removed in one piece and the tissue identified histologically as a pT2a malignancy. The lesion has the following properties: dimensions of 2.3 × 2 × 1 cm; Breslow thickness of 1.9 mm; mitotic index of 4 mitoses/5 HPF; margin of at least 0.1 cm healthy tissue; positive staining patterns of HMB-45 (+), Melan A (+) and S100 (+) markers; and negative CK AE1/AE3 (–) marker (Figure 2).
Following tumor resection, the patient was subjected to further investigation including abdominal and retroperitoneal ultrasound as well as pelvic ultrasound. The abdominal ultrasound showed hypo-echoic mass with dimensions of 44 × 26 × 33 mm localized on the left umbilical region slightly lateral to the midline suggesting a pathological lymph node that needed further investigation. On the other hand, the retroperitoneal and pelvic scans were negative. More radical therapy was performed on the patient including an expanded resection but the tissue histopathology failed to show any evidence of the presence of cancer cells.
Further findings were obtained after performing an abdominal CT scan. We found a pathological mass of 37 × 41 mm with inhomogeneous and hypo-echogenic texture (Figure 3). Closely adhering to the small bowel loop, we found gastrointestinal stromal tumor (GIST). In order to ensure patient safety and due to the high morbidity and...


View full text...