Fine needle aspiration cytology of primary and metastatic gastrointestinal stromal tumour

Umbilical metastasis as an initial presentation of gastrointestinal stromal tumour diagnosed on aspiration cytology

Umbilical metastasis is a rare event, with a majority being adenocarcinomas. Metastatic squamous cell carcinoma, small cell carcinoma, lymphoma, melanoma, and rarely malignant mesenchymal tumours like leiomyosarcoma can occur as umbilical nodules. These often emerge during a known malignancy, but once in a while they may be an initial presentation of an undetected tumour. An extensive literature search failed to reveal a case of gastrointestinal stromal tumour (GIST) with umbilical metastasis as an initial presentation. We believe that this is an exceptional phenomenon. The diagnosis may easily be missed considering the rarity of this occurrence. A history of primary diagnosis of GIST, when available, is helpful. Here we present cytological findings of metastatic GIST presenting as an umbilical lump, where the diagnosis was reached with the help of limited immunocytochemistry. A timely diagnosis is valuable for locating the primary and initiating surgical management, which may have survival benefits for the patient.

Gastrointestinal Stromal Tumors-A Mini Review

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract. They are potentially malignant, and have an unpredictable evolution. The origin of these tumors is in the interstitial cells of Cajal, which are cells that are interposed between the intramural neurons and the smooth muscle cells of the digestive tract. GISTs are characterized by mutations in the gene c-Kit, but also other mutations, such as those of the platelet-derived growth factor receptor alpha. The most common locations of these tumors are the stomach and small intestine, although they can occur at any level of the digestive tract and occasionally in the omentum, mesentery and peritoneum. Most cases of GISTs are sporadic, and about 5% of cases are part of family genetic syndromes. The correct diagnosis of GIST is determined by histopathological examination and immunohistochemistry. According to histopathology, there are three main types of GISTs: spindle cell type, epithelioid type and mixed type. The therapeutic management of GIST includes surgery, endoscopic treatment and chemotherapy. The prognosis of patients with GIST varies depending on a number of factors, such as risk category, GIST stage, treatment applied and recurrence after treatment.