Pulmonary histoplasmosis producing a spindle cell "pseudotumor".

Pulmonary spindle cell proliferations have been reported in association with a limited group of infectious agents. These lesions are rare and identified most often in the setting of immunosuppression. Because their appearance can simulate a spindle cell neoplasm, they are diagnostically treacherous, sometimes delaying antimicrobial therapy or resulting in unnecessary surgery. We report a case of a spindle pseudotumor of the lung resulting from Histoplasma capsulatum infection, a previously unreported cause of a spindle cell lesion in the lung. The patient was a 67-year-old woman in whom positron emission tomography-positive nodules developed in the left lung and left mediastinum. The patient had undergone renal transplantation and was receiving immunosuppressive therapy with mycophenolate, tacrolimus, and low-dose prednisone. Infection with H capsulatum was confirmed by culture of pleural effusion fluid, DNA probe analysis of the pleural fluid culture isolate, urinary Histoplasma antigen detection, and Grocott methenamine silver stains of tissue sections. To our knowledge, this is the first case of a spindle cell "pseudotumor" of the lung resulting from histoplasmosis. It highlights the importance of performing special stains for organisms when evaluating pulmonary spindle cell lesions in an immunocompromised host.

Intestinal spirochetosis in children: five new cases and a 20-year review of the literature.

Intestinal spirochetosis (IS) is an unusual infection in children, one with no standard therapeutic options. This article reports the findings on 5 new cases in conjunction with a 20-year review of the pediatric literature. The diagnosis of IS in children requires a high degree of suspicion by the physician, as many cases present with abdominal pain, chronic diarrhea, and/or hematochezia associated with a normal endoscopic examination. Silver stains (Dieterle or Whartin-Starry) are the preferred confirmatory stains on tissue sections. Giemsa (Diff-Quik) and periodic acid-Schiff stains may also be of value. Current literature favors the use of metronidazole in adult patients with IS, yet little information is available regarding treatment options in pediatric cases. This review indicates that a macrolide antibiotic with or without metronidazole may represent the best therapeutic choice for children. Further investigations are needed to determine the correlation between IS and coexisting gastrointestinal diseases and/or immunodeficiencies.