No abstract

The clinicopathologic features of a case of congenital hemangiopericytoma are described and compared with those of previously reported cases. Features connotative of malignancy in adult or childhood hemangiopericytomas, such as high mitotic activity, increased cellularity, and tissue necrosis or hemorrhage, are frequently observed in congenital tumors. However, the congenital tumors are biologically benign. Spontaneous tumor regression observed in our case further suggests a conservative approach in the treatment of congenital hemangiopericytomas.

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“Lethal midline granuloma” should be only a clinical term for rapidly evolving destructive lesions of the nose and the deep facial tissues. Such clinical presentation—after specific infections and carcinomas have been excluded—may occur in 3 different clinicopathologic entities: midline malignant reticulosis (polymorphic reticulosis), Wegener's granulomatosis, and malignant lymphoma of one of the accepted histologic types. One representative case of each of these is reported here, histologic criteria for differential diagnosis are outlined, and the literature is reviewed. Midline malignant reticulosis is defined as a lymphoproliferative disorder involving initially the nasal and the paranasal soft and bony parts and capable of later dissemination. Treatment should be based on the pathologic diagnosis made on viable biopsy tissue. Midline malignant reticulosis may have a better prognosis than malignant lymphoma of the nasal cavity when treated with tumoricidal doses of irradiation. On the other hand, Wegener's granulomatosis may respond to immunosuppresive drugs.