Polymorphic reticulosis (lethal midline granuloma) and lymphomatoid granulomatosis: identical or distinct entities?

Two cases of polymorphic reticulosis were studied. Both cases had a fatal clinical course, that of the second case being rapid and progressive and ending 6 months after the onset of the disease with little demonstrable effect of steroid therapy. Biopsy material was obtained in both patients, and both were submitted to a post-mortem examination. The first case showed typical angiocentric, angiodestructive, polymorphous lymphoreticular infiltrates, involving the pharyngeal region and the tongue. The second case demonstrated these same lesions in the midfacial region, the lungs and the skin. A possible identify between polymorphic reticulosis and lymphomatoid granulomatosis is discussed (because of the coexistence of identical lesions in the midfacial region and in the lung parenchyma in the second case). Wegener's granulomatosis in limited and disseminated forms and malignant lymphoma are considered in the differential diagnosis.