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Joined 2026-09-21 Message
Incoming links: What Is Cancer? by the National Cancer Institute
The typical contrast is between a highly cellular, relatively scantily supported encephaloid cancer and a fibroplastic growth composed predominantly of elongated cells and developing fibrous material. Neither historical name is a complete modern tumour classification.
In encephaloid cancer, a thin preparation from a viable region shows crowded, variably sized cells, often rounded, oval, polygonal or irregular, with conspicuous cell nuclei and a prominent cell nucleolus. Some cells have more than one cell nucleus; the cytoplasm and nuclear proportions vary. In sections, the cells form masses or groups separated by a comparatively delicate vascular stroma. Where the lesion is a carcinoma, cohesive epithelial arrangements and invasion of surrounding tissue help establish its nature. The scant support helps explain the soft, brain-like gross consistency denoted by “encephaloid”; it does not mean that the growth is made of brain tissue.
A rapidly growing soft tumour may also show evidence of mitosis, haemorrhage, necrosis and granular or fatty cellular debris. These features vary with sampling and are not the definition of every historical encephaloid lesion. The viable advancing edge is more informative about cell type and invasion than a completely broken-down centre. A modern interpretation combines architecture, cell morphology and, where needed, immunohistochemistry; one large nucleolated cell is not a universal “cancer corpuscle.”[ref]
Neoplasia by the University of Utah WebPath. Malignant neoplasms: cytological atypia, nuclear features, epithelial and mesenchymal classification
[ref]What Is Cancer? by the National Cancer Institute. How cancer differs from normal cells; invasion and tumour classification
In a typical fibroplastic growth, the conspicuous elements are oval or spindle-shaped cells, with elongated cell nuclei, tapering processes and intercellular material taking on a fibrillar character. The cells may run in parallel bundles or interlacing groups. Some areas contain many apparently free oval cell nuclei; other areas show more mature fibres and fewer obvious cell bodies. A teased preparation helps display individual elongated cells and fibres, whereas a section shows how the bundles relate to vessels and surrounding tissue.
The historical interpretation was of a growth resembling developing connective tissue. It should not be translated automatically into either a harmless fibroma or a specific modern fibrosarcoma. Contemporary descriptions recorded recurrence and malignant behaviour in some growths put in this broad category.[ref]
Illustrations of the Pathology of Cancer by John Zachariah Laurence. pp. 35–37: fibres, elongated nuclei, fibroplastic cells and variable clinical behaviour
Cell shape must be read with tissue architecture and behaviour. Apparent resemblance to fibroblasts does not establish benignity, and a scant-fibred soft growth is not by itself proof of epithelial origin.An historically appropriate classification distinguishes the hard, soft, gelatinous, pigmented and epithelial malignant growths, together with recurrent and destructive growths whose place in “cancer” was disputed. Modern classification instead distinguishes tumours by cellular lineage and biological behaviour.
The quotation marks around “Malignant” matter. In 1867 the clinical grouping did not have a single settled boundary in histology. Infiltration, destructive growth, return after removal, spread to distant sites and progressive constitutional illness were warning features; hardness or rapid growth alone was not a sufficient definition. A contemporary review of an 1866 textbook explicitly disputed confused descriptions of hard and soft cancer, illustrating that this was already a live diagnostic controversy.[ref]
Review of Demonstrations of Microscopic Anatomy (1866 book). Discussion under “tumours”, contrasting scirrhus with encephaloid, melanotic and colloid growths and rejecting an indiscriminate use of “cancer”
A useful period classification, without pretending that every contemporary author drew the same boundaries, is:
- Scirrhous carcinoma, or hard cancer. Abundant firm fibrous supporting tissue makes a hard, often contracted growth, classically in the breast. Retraction and fixation reflect invasion and contraction of that supporting tissue. “Hard” describes the gross appearance; it is not a separate modern cellular lineage.
- Encephaloid cancer, or medullary/soft cancer. The name refers to soft, brain-like tissue, often richly cellular and prone to rapid growth, breakdown and haemorrhage. The historical label could include more than one modern diagnosis; it does not mean a tumour of the brain.
- Colloid cancer. A gelatinous appearance associated with abundant mucin. Some such lesions would now be classified as mucinous carcinomas; appearance alone cannot retrospectively determine their modern identity.
- Melanotic tumour. Dark pigment supplied a gross category. Many malignant examples belong to modern melanoma, arising from melanocytes, but pigmentation is neither necessary nor sufficient for melanoma. Pigmented examples could also be treated as varieties within other period categories.
- Epithelioma, or epithelial cancer. A growth exhibiting epithelial structure, especially at skin and mucous membrane surfaces. Many examples correspond to squamous cell carcinoma. A locally destructive rodent ulcer, now generally basal cell carcinoma, was sometimes separated because distant spread was unusual.
- Recurrent fibroid tumour and related “fibroplastic” or other sarcomas. These could return repeatedly and invade locally despite differing from the period's typical cancer. They were sometimes called semi-malignant. A reported 1866 recurrent fibroid tumour developed distant deposits after apparently successful local treatment: a vivid reason that a purely local category could fail.[ref]St George's Hospital Reports (1866). Case of recurrent fibroid tumour of the thigh, subsequent constitutional disease and post-mortem deposits; terminology is the report's historical terminology
Those are overlapping historical descriptive groups, not six mutually exclusive modern diagnoses. Nor does every growth historically called “sarcoma” meet the modern definition of sarcoma.
The modern organising principle asks what cells are malignant. Carcinoma arises from epithelium; sarcoma arises in bone or soft tissue; melanoma arises from melanocytes; lymphoma and leukaemia concern blood-forming or immune cells. Other families include central nervous system and germ cell tumours. A solid lump is not essential for cancer. Within a family, histology, immunohistochemistry and appropriate molecular diagnostics refine the diagnosis. Tumour grade describes features of aggressiveness, whereas tumour stage describes extent of disease.[ref]
This also corrects the old inference that recurrence must reflect a mysterious constitutional deposit: local residual disease and metastasis are distinct mechanisms, and an apparently circumscribed growth may already have disseminated.