Merkel Cell Carcinoma With Gastric Metastasis and Review of Literature.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neoplasm, with a propensity for recurrence and metastasis. Very few cases of metastases to the gastrointestinal tract have been reported in the medical literature. OBJECTIVES: The aim of this study was to report a case of MCC metastasizing to the stomach, its clinical presentation, and its management. METHODS: A PubMed search was made using the following search terms: "Merkel cell carcinoma," "gastric," and "metastasis." RESULTS: The investigators report a case of MCC metastatic to the stomach presenting with melena, syncope, early satiety, increasing fatigue, and unintentional weight loss. The other known cases of gastrointestinal metastasis of MCC are summarized and critically reviewed. CONCLUSIONS: Although MCC spreading to the stomach is exceedingly rare, because of MCC's high recurrence rate and metastatic potential, it should be considered in patients with histories of MCC presenting with recent weight loss, early satiety, and gastrointestinal bleeding.

Expansion of hematopoietic stem cells for transplantation: current perspectives.

Hematopoietic stem cells (HSCs) are rare cells that have the unique ability to self-renew and differentiate into cells of all hematopoietic lineages. The expansion of HSCs has remained an important goal to develop advanced cell therapies for bone marrow transplantation and many blood disorders. Over the last several decades, there have been numerous attempts to expand HSCs in vitro using purified growth factors that are known to regulate HSCs. However, these attempts have been met with limited success for clinical applications. New developments in the HSC expansion field coupled with gene therapy and stem cell transplant should encourage progression in attractive treatment options for many disorders including hematologic conditions, immunodeficiencies, and genetic disorders.