Related Experiment Videos
HMB-45 reactivity in renal angiomyolipoma and lymphangioleiomyomatosis
1Lillian and Henry M. Stratton-Hans Popper Department of Pathology, Mount Sinai School of Medicine, City University of New York, NY 10029.
Abstract:
Recent reports have elucidated the variety of tissue types that can react with HMB-45. Consistent positivity has been demonstrated in angiomyolipomas, but only in the smooth-muscle cells. In this report, we examine five renal angiomyolipomas and 20 mesenchymal lesions with similar morphological features and with a possibly similar histogenesis. These include one retroperitoneal lymphangioleiomyomatosis, five epithelioid leiomyomas, nine leiomyosarcomas with epithelioid features, and five alveolar soft part sarcomas. HMB-45 demonstrated a strong diffuse cytoplasmic positive reaction with the smooth-muscle component in all cases of renal angiomyolipoma and in the one case of lymphangioleiomyomatosis. All alveolar soft part sarcomas, leiomyomas, and leiomyosarcomas were uniformly negatively stained by this antibody. We discuss the widening spectrum of lesions that are reactive with HMB-45 and the relationship of angiomyolipoma and lymphangioleiomyomatosis.
Insights
The HMB-45 antibody consistently stains smooth muscle cells in angiomyolipomas and lymphangioleiomyomatosis. Other mesenchymal lesions, including leiomyosarcomas and soft part sarcomas, did not react with HMB-45.
Area of Science:
- Immunohistochemistry
- Surgical Pathology
- Oncology
Background:
- The HMB-45 antibody is a marker used in diagnosing various tumors.
- Previous studies indicated HMB-45 reactivity is primarily in smooth muscle cells of angiomyolipomas.
- The spectrum of HMB-45 reactivity and its diagnostic utility in mesenchymal lesions requires further elucidation.
Purpose of the Study:
- To investigate the reactivity of the HMB-45 antibody in renal angiomyolipomas and a panel of mesenchymal lesions.
- To compare HMB-45 staining patterns in angiomyolipomas with those in lymphangioleiomyomatosis, leiomyomas, leiomyosarcomas, and alveolar soft part sarcomas.
- To discuss the diagnostic implications of HMB-45 in differentiating these entities.
Main Methods:
- Immunohistochemical analysis using the HMB-45 antibody.
- Evaluation of five renal angiomyolipomas.
- Assessment of 25 other mesenchymal lesions: 1 lymphangioleiomyomatosis, 5 epithelioid leiomyomas, 9 epithelioid leiomyosarcomas, and 5 alveolar soft part sarcomas.
Main Results:
- All five renal angiomyolipomas showed strong, diffuse cytoplasmic positivity for HMB-45 in their smooth muscle components.
- The single case of retroperitoneal lymphangioleiomyomatosis also exhibited strong HMB-45 positivity in smooth muscle cells.
- Epithelioid leiomyomas, leiomyosarcomas, and alveolar soft part sarcomas were uniformly negative for HMB-45.
Conclusions:
- HMB-45 antibody is a reliable marker for the smooth muscle component of angiomyolipoma and lymphangioleiomyomatosis.
- The study expands the understanding of HMB-45 reactivity, highlighting its utility in distinguishing these tumors from other mesenchymal lesions.
- HMB-45 positivity supports a relationship between angiomyolipoma and lymphangioleiomyomatosis, likely originating from perivascular epithelioid cells.