RESUMEN
We describe a rare case of malignant gastrointestinal stromal tumor (GIST) of the esophagus presenting in an HIV-positive man. Not only did the tumor arise from an unusual anatomic site for GIST, namely, the esophagus, but it also had a predominant epithelioid cell morphology that is uncommon and preferentially associated with aggressive behavior. Exhaustive immunohistochemical studies showed strong reactivities to the classic GIST marker, CD34, and to the current more sensitive and more specific GIST marker, CD117/ c-kit protein. This immunophenotype corresponded to that of stromal tumors arising in the more common sites like stomach and small intestine as well as to that of a reported series of esophageal GISTs in the general population. Mutations of the c-kit protein was detected in the tumor, confirming previous observations. This further documents that esophageal GIST and the more common benign esophageal spindle cell lesions are pathologically distinct entities and despite its rarity, esophageal GIST should be recognized by pathologists and clinicians. The occurrence of this tumor in an HIV-positive patient is coincidental, and it resulted in an extremely unusual metastatic site that has not been reported for GISTs.
Asunto(s)
Neoplasias Esofágicas/patología , Tumores del Estroma Gastrointestinal/patología , Infecciones por VIH/patología , Neoplasias Complejas y Mixtas/secundario , Antígenos CD34/análisis , Biomarcadores de Tumor/análisis , Endosonografía , Células Epitelioides/química , Células Epitelioides/patología , Neoplasias Esofágicas/química , Tumores del Estroma Gastrointestinal/química , Tumores del Estroma Gastrointestinal/complicaciones , Infecciones por VIH/complicaciones , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Neoplasias Complejas y Mixtas/química , Neoplasias Complejas y Mixtas/cirugía , Proteínas Proto-Oncogénicas c-kit/análisisRESUMEN
We report a rare case of cellular angiolipoma of the breast in a 73-year-old woman with abnormal mammographic findings. Histopathologic examination of the tumor revealed cellular spindle cell areas associated with collapsed and patent blood vessels in a background of mature adipose tissue. A salient feature of this tumor, which was an important clue to the diagnosis, was the presence of intravascular fibrin thrombi. Immunohistochemical studies showed reactivities for endothelial and muscle markers, highlighting the obscured angiomatous component in the cellular areas of the tumor. Failure to recognize this entity may potentially lead to diagnostic pitfalls that include angiosarcoma and Kaposi's sarcoma, two of the better recognized entities in this region.