Diagnostic and differential diagnostic aspects in histiocytosis X diseases.

Diagnostic and differential diagnostic aspects of the known manifestations of histiocytosis X are discussed with respect to our own findings. It is our considered opinion that the term "histiocytosis X" should not be employed in isolation for diagnostic purposes. Rather, one should make an effort to designate the disease exactly in stating the prognosis for a particular patient. Both clinical and morphologic parameters must be considered in making this exact diagnosis.