Cutaneous presentation of gastrointestinal adenocarcinoma

Abstract

Seeding of a central nervous system malignancy to the abdominal cavity is an uncommon but well documented complication of a ventriculoperitoneal (VP) shunt. However, the metastasis of a primary gastrointestinal cancer to the skin via a VP shunt is extremely rare. We report the clinical case of an 85-year-old male who presented with a right upper quadrant nodule over his shunt, which on histopathology and tumour marker profile was diagnosed as an adenocarcinoma of likely upper gastrointestinal origin. This case illustrates the importance of proceeding to biopsy to inform prognosis and management, despite the risks of shunt infection.

Figure 1:

Right upper quadrant lesion overlying intra-abdominal insertion site of ventriculoperitoneal shunt.

Figure 2:

Multiple subcutaneous nodules tracking along the ventriculoperitoneal shunt.

Figure 3:

Biopsy sample demonstrating (a) dermal proliferation of infiltrating malignant glands (haematoxylin and eosin stain, ×20 magnification), (b) marked nuclear atypic and mitotic activity (haematoxylin and eosin stain, ×400 magnification) and (c) pancytokeratin stain of adenocarcinoma (×40 magnification).