Splenic vascular tumors: a histologic, immunophenotypic, and virologic study

Area of Science:

• Pathology
• Oncology
• Immunohistochemistry

Background:

• Splenic vascular tumors encompass diverse entities, some specific to the spleen.
• Accurate classification is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the distinct immunophenotypic and morphologic features of splenic vascular tumors.
• To differentiate between hemangiomas, littoral cell angiomas, angiosarcomas, and hamartomas using immunohistochemistry.
• To assess the presence of Kaposi's sarcoma-associated herpesvirus (KSHV) in these tumors.

Main Methods:

• Analysis of 22 splenic vascular proliferations (10 hemangiomas, 6 littoral cell angiomas, 4 angiosarcomas, 2 hamartomas).
• Paraffin section immunohistochemistry with a comprehensive antibody panel.
• Polymerase chain reaction (PCR) for Kaposi's sarcoma-associated herpesvirus (KSHV) detection.

Main Results:

• All tumors expressed vimentin; one angiosarcoma showed focal keratin positivity.
• CD31 was universally expressed. CD34 expression varied, notably absent in littoral cell angiomas.
• Distinct CD marker profiles were identified: CD34-/CD68+/CD21+/CD8- for littoral cell angiomas and CD68-/CD21-/CD8+ for hamartomas.
• Frequent CD68 expression in diffuse hemangiomas suggested a difference from localized hemangiomas.
• Kaposi's sarcoma-associated herpesvirus (KSHV) was not detected in any case.

Conclusions:

• Splenic vascular tumors exhibit distinct immunophenotypic profiles.
• Immunohistochemistry, particularly CD marker analysis, is valuable for classifying these tumors.
• Littoral cell angiomas and hamartomas possess characteristic immunophenotypes, aiding their differentiation from other splenic vascular lesions.