Malignant

MALIGNANT, an epithet applied to cases of diseases with a particularly unfavorable course, where the latter may consist of the rapid progression of the disease with an unfavorable outcome, or the intensity of symptoms, or, finally, both simultaneously. The first and second signs, however, do not always coincide: diphtheria, for example, usually proceeds with an insignificant increase in body temperature (the so-called "cold diphtheria"), thus giving no cause for concern to an inexperienced person. The intoxication in these cases is so strong that the proper temperature reaction does not develop due to the suppression of the reacting mechanisms. Malignancy in some cases is determined by the very nature of the pathological process, while in others it depends on the character and degree of the organism's reactivity (for example, cancer and sarcoma are called malignant neoplasms, although the degree of their malignancy varies in different cases depending on localization and other conditions); on the other hand, the same virus can cause a mild infectious disease in one subject and a very severe one in another.

With regard to infectious diseases specifically, however, it must be borne in mind that, in addition to purely individual characteristics of the organism, other conditions also play a role in determining the degree of malignancy, and these conditions exist on the part of both the macro- and the microorganism. Many infectious diseases, when falling on virgin soil, i.e., in an environment where they have not been previously, proceed with a malignant character, causing real devastation in the population, whereas when they become common in a certain area, the same infections acquire a relatively more benign character. This is the case, for example, with tuberculosis (galloping tuberculosis, miliary tuberculosis of the Kalmyks, Bashkirs, etc.). In these cases, in addition to selection, one should keep in mind the possibility of gradual immunization of the population. It is not excluded, however, in a number of cases, that there is a possibility of a weakening of the virulence of the pathogen itself over time under the influence of certain factors that are not yet easily definable. Syphilis, when introduced from America to Europe, initially had a much more malignant course than it did later. Sometimes the degree of malignancy of a pathological process is to a certain extent determined by the age of the individual (juvenile diabetes; cases of cancer at a young age), which apparently must be explained by the reduced resistance of the organism.

The signs of benignity and malignancy of a process, generally sufficiently clear, can sometimes appear to a significant degree conditional. Thus, the signs of malignant neoplasms are considered to be the ability to produce metastases, to grow into surrounding tissues and destroy them (so-called infiltrating atypical growth), and to adversely affect the general nutrition of the organism, but the same can sometimes be observed in benign tumors (metastases of chondromas, growth of fibromas of the skull base into the orbital cavity or the maxillary sinus with erosion of cartilage and bone; exhaustion from bleeding due to uterine fibroids, etc.). On the other hand, the rapid growth characteristic of malignant tumors is not expressed in many forms of skin cancer. Thus, the concept of malignant growth and a malignant process is primarily clinical and anatomical; determining the malignancy of a process histologically requires great caution; true, in the majority of cases, no difficulties arise here. The name "malignant pustule" (pustula maligna) in anthrax is likewise determined by the seriousness of such cases, the usually sufficiently pronounced general phenomena on the part of the organism, and the danger of the process transitioning into general sepsis.