Faculty Bibliography

Histoplasmosis is a self-limited and asymptomatic disease in immunocompetent individuals. Patients with untreated human immunodeficiency virus (HIV) or immune suppression due to medications such as corticosteroids can present with disseminated and life-threatening infections. We present a case of a 60-year-old female that presented with recurrent diarrhea that was found to have isolated gastrointestinal (GI) histoplasmosis. The rarity of this case is due to the isolated colonic involvement and lack of respiratory symptoms (the portal of infection). In conclusion, clinicians should be aware of isolated histoplasmosis affecting the GI tract and careful endoscopic evaluation with adequate sampling is warranted to confirm the diagnosis.

Background: The incidence of small intestinal neuroendocrine tumors (SI-NETs) has significantly increased over the last several decades, with overall 5-year survival rates varying from 56% to 79%. Although tumor size, mitotic rate and Ki-67 index provide relevant information related to tumor aggressiveness and prognosis, sensitive and specific biomarkers that can accurately predict prognosis are generally lacking. CD47 is an integrin-associated protein which inhibits macrophage phagocytosis. Overexpression olf CD47 has been associated with increased tumor growth and metastasis in a variety of malignancies and anti-CD47 treatments are being investigated in hepatocellular carcinoma and pancreatic neuroendocrine tumors (P-NETs). In this study, we examine the prognostic implications of CD47 expression in SI-NETs. Design: 25 well differentiated SI-NET (13 G1 and 12 G2) resection specimens were selected and analyzed for CD47 expression using immunohistochemistry. The cohort included 9 females and 16 males, ranging from 21 to 77 years of age. H-score method was used to evaluate both staining intensity (0-3) and percentage of positive cells. One-way analysis of variance or Student's t-test was utilized to correlate mean H-score with various clinical parameters. Results: Positive cytoplasmic and membranous CD47 staining was seen in all samples of SI-NETS, but not in adjacent noncancerous small intestinal epithelium. The staining pattern is diffuse. At the time of resection, 17 cases showed lymph node metastasis. The H-score of CD47 does not relate to tumor size, stage, grade, mitotic rate or Ki67 proliferation index. Interestingly, the cases with lymph node metastasis have significant lower H-score of CD47 than those without lymph node metastasis (192.9+/-8.4 vs 233.1+/-19.4, P=0.035). Overexpression of CD47 inversely associates with lymph node metastasis in SI-NETS. Conclusions: This is the first study to investigate the expression of CD47 in human SI-NETs and its correlation with currently suggested prognostic parameters. We found CD47 overexpression in all SINETs, and CD47 expression significantly correlated with lymph node metastasis. Our data suggests CD47 might be a novel marker for predicting prognosis of SI-NETs