I was on my way to the Univ of MD Medical Center in Baltimore yesterday to meet with the head of the Gastroenterology department and a dietitian. Well I am sure you know based on the title it was my primary Doctor on the line with results from the bone Biopsy…
Well we are by far out of the woods yet as the initial diagnosis is “METASTATIC UNDIFFERENTIATED MALIGNANT NEOPLASM” What??? Just a fancy couple of words that states it’s cancer but they are not sure what type OR where it started (cancer that spreads to the bones that comes from somewhere else) so I will be scheduled for another MRI as soon as possible, hopefully Monday or the latest Tuesday… So here we go again to get to the source… UGH…
Love you all,
Keith
CANCER, TECHNICAL INFORMATION AND DEFINITIONS
A new growth is a “neoplasm.” Neoplasia literally means “new growth.” The term “tumor” was originally applied to the swelling caused by inflammation. Neoplasms also may induce swellings, but by long precedent, the non-neoplastic usage of “tumor” has passed into limbo; thus, the term is now equated with neoplasm. Oncology (Greek “oncos”= tumor) is the study of tumors or neoplasms. Cancer is the common term for all malignant tumors.
CHARACTERISTICS OF BENIGN AND MALIGNANT NEOPLASMS
In the great majority of instances, the differentiation of a benign from a malignant tumor can be made morphologically with considerable certainty; sometimes, however, a neoplasm defies catagorization. Occasionally this prediction is confounded by a marked discrepancy between the morphologic appearance of a tumor and its biologic behavior: An innocent face may mask an ugly nature. Such deception or ambiguity, however, is not the rule; in general, there are criteria by which benign and malignant tumors can be differentiated, and they behave accordingly. These differences can conveniently be discussed under the following headings: (1) differentiation and anaplasia, (2) rate of growth, (3) local invasion, and (4) metastasis.
MALIGNANT TUMORS
The nomenclature of malignant tumors essentially follows the same schema used for benign neoplasms, with certain additions. Malignant tumors are usually called sarcomas (Greek “sar” = fleshy) because they have little connective tissue stroma and so are fleshy, e.g., fibrosarcoma, liposarcoma, and leiomyosarcoma for smooth muscle cancer and fibromyosarcoma for a cancer that differentiates toward striated muscle. Malignant neoplasms of epithelial cell origin, derived from any of the three germ layers, are called carcinomas. Thus cancer arising in the epidermis of ectodermal origin is a carcinoma, as is a cancer arising in the mesodermally derived cells of the renal tubules and the endodermally derived cells of the lining of the gastrointestinal tract. Carcinomas may be further qualified. One with a glandular growth pattern microscopically is termed an adenocarcinoma, and one producing recognizable squamous cells arising in any epithelium of the body would be termed a squamous cell carcinoma. It is further common practice to specify, when possible, the organ of origin, e.g., a renal cell adenocarcinoma or bronchogenic squamous cell carcinoma. Not infrequently, however, a cancer is composed of undifferentiated cells and must be designated merely as a poorly differentiated or undifferentiated malignant tumor.
In most neoplasms, benign and malignant, the parenchymal cells bear a close resemblance to each other, as though all were derived from a single cells, as indeed we know to be the case with most cancers. Infrequently divergent differentiation of a single line of parenchymal cells creates what are called mixed tumors. The best example is the mixed tumor of salivary gland origin. These tumors contain epithelial components scattered within a myxoid stroma that sometimes contains islands of apparent cartilage or even bone. All these elements, it is believed, arise from epithelial and myoepithelial cells of salivary gland origin; thus the preferred designation of these neoplasms is pleomorphic adenoma. The teratoma, in contrast, is made up of a variety of parenchymal cell types representative of more than one germ layer, usually all three. They arise from totipotential cells and so are principally encountered in the gonads but rarely in sequestered primitive cell rests elsewhere. These totipotential cells differentiate along various germ lines, producing, for example, tissues that can be identified as skin, muscle, fat, gut epithelium, tooth structures, and, indeed, any tissue of the body.
METASTASIS
Metastases are tumor implants discontinuous with the primary tumor. Metastasis unequivocally marks a tumor as malignant because benign neoplasms do not metastasize. The invasiveness of cancers permits them to penetrate into blood vessels, lymphatics, and body cavities, providing the opportunity for spread. With few exceptions, all cancers can metastasize. The major exceptions are most malignant neoplasms of the glial cells in the central nervous system, called gliomas, and basal cell carcinomas of the skin. Both are highly invasive forms of neoplasia (the latter being known in the older literature as rodent ulcers because of their invasive destructiveness), but they rarely metastasize. It is evident then that the properties of invasion and metastasis are separable.
In general, the more aggressive, the more rapidly growing, and the larger the primary neoplasm, the greater the likelihood that it will metastasize or already have metastasized.
Approximately 30% of newly diagnosed patients with solid tumors (excluding skin cancers other than melanomas) present with metastases. Metastatic spread strongly reduces the possibility of cure; hence short of prevention of cancer, no achievement would confer greater benefit on patients than methods to prevent distant spread.
PATHWAYS OF SPREAD
Dissemination of cancers may occur through one of three pathways: (1) direct seeding of body cavities or surfaces, (2) lymphatic spread, and (3) hematogenous spread. Although direct transplantation of tumor cells, as for example on surgical instruments, may theoretically occur, it is rare and, in any event, an artificial mode of dissemination that is not discussed further. Each of the three major pathways is described separately.
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