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neoplasia

neoplasia / cancer / tumours

benign neoplasia

epithelial:

  • Papillomata (surface epithelia):
    • sessile
    • pedunculated (polyps)
    • villous
    • Squamous cell skin, tongue, larynx, anus (ie. where stratified sq. epith.)
      • acanthosis: incr. thickness of prickle cell layer
      • hyperkeratosis: incr. amt of adherent keratin
      • parakeratosis: retention of nuclei of desq. keratinised cells;
    • Transitional cell urinary passages, esp. bladder - usually villous;
      • usually regarded as malignant & reported as so (recur, etc);
    • Columnar cell colon (villous papilloma not the tubular adenoma), breast ducts;
  • Adenomata (solid glandular tissue):
    • dense masses of acini (except endocrine - solid groups of cells only)
    • acini lined by either columnar or cuboidal shaped cells;
    • if in glands that open to surface → pedunculated polyps;
    • may secrete XS hormones (eg APUD-cell tumours, etc);
    • Cystadenoma variant with elaborate cystic spaces - esp. ovary;
    • Fibroadenoma variant with XS CT stroma (esp. breast)
      • hard pericanalicular CT type
      • soft intracanalicular CT type
      • cystosarcoma phyllodes - myxoid stroma (breast)

connective tissue

  • Fibroma many sites eg. skin, stomach, ovary;
  • Myxoma uncommon, resembling Wharton's jelly: atrium, jaw;
  • Myoma
  • Leiomyoma sm. muscle (uterus, arrector pili, b.v) - commonest tumours!
  • Rhabdomyoma striated muscle (incl. heart) - v.uncommon, esp. tub.sclerosis;
  • Nerve Sheath:
    • Neurofibroma
    • Schwannoma (also called neurinoma or neurilemmoma);
    • Meningioma
  • Lipoma
  • Giant-cell tumour of bone:
    • Chondroma/Synovioma
    • Osteoma
  • Mesothelioma
  • Carotid-body tumour

fetal/embryonic & germ cell

  • Teratoma consists of multiple tissues foreign to part; ovary > testes;
  • Hydatidiform mole trophoblastic;
  • Ganglioneuroma

malignant neoplasia

types and characteristics

  • usually indicated by pleomorphism, mitoses ± invasion b.memb;
epithelial (Carcinoma)
  • stroma well formed usually; early lymph. spread; esp → liver;
  • Squamous-cell from strat.squam. epith. (or from epith. undergone sqam. metaplasia);
  • Basal cell actually of intermediate behaviour;
  • Transitional cell urinary passages; well-diff. → anaplastic; +/- squamous change;
  • Glandular
    • graded by:
      • tubule formationn; regularity size/shape/stain nuclei, mitoses;
      • stromal reactions alter appearance:
      • scirrhous - hard, fibrotic (most breast Ca & many GIT);
        • eg. linitus plastica; annular/purse-string of colon;
      • medullary/encephaloid - little stroma → soft
        • eg. breast Ca in lactation; cauliflower of caecum;
      • adenocarcinoma - best differentiated - has tubules;
      • carcinoma simplex - no attempt at central cavitation to produce acini (breast)
      • anaplastic carcinoma - sheet of loosely attached cells
      • giant cell carcinoma
      • squamous metaplasia of adenocarcinoma
      • signet-ring cell carcinoma - much mucus in cell
connective tissue malignant neoplasia(Sarcoma)
  • more rapid growth; mainly blood-borne spread → lungs esp.
  • poorly formed stroma; more radioresistant than Ca;
  • Fibrosarcoma
  • Neurofibrosarcoma
  • Liposarcoma
  • Leiomyosarcoma
  • Rhabdomyosarcoma
  • Chondrosarcoma
  • Osteosarcoma
  • Malig. mesothelioma
  • Angiosarcoma
  • Malig. meningioma
  • Malig. melanoma - cutan.; mucosal; uveal; meningeal; adrenal;
lymphomata et al
  • Hodgkin's
  • Non-Hogkin's
  • Multiple myeloma
  • Leukaemia
fetal/embryonic & germ cell malignant neoplasia
  • Choriocarcinoma trophoblastic, secreting HCG;
  • Nephroblastoma (Wilm's) infancy/childhood;
  • Retinoblastoma definite hered. incidence; infants;
  • Malignant Teratoma young-middle age adults;
  • Seminoma/Dysgerminoma older age gp than teratomas;
  • Medulloblastoma 4th ventricle; mainly young children;
  • Neuroblastoma adrenal medull or symp. ganglia; infancy;
  • Hepatoblastoma very rare;
  • Chordoma/Craniopharyngioma - rare

characteristics of malignant tumours

  • invasiveness (eg. through basement membrane)
  • metastasise - see neoplastic spread
  • rapid increase in size usually more than benign tumours;
  • cell cycling time usually N. but incr. no. of cells in mitosis & may be incr. time spent in mitosis;
  • irregularity of size, shape & staining of nuclei due to:
    • synthesis of DNA prior to division → nuclear enlargement & hyperchromatism;
    • formation of aneuploid & polypoid cells as abnormal mitoses;
  • less similarity with normal tissue than benign tumours as abn. differentiation;
    • anaplasia is where little or no normal differentiation seen on microscopy;
  • giant cells may be present in certain tumours, if anaplastic, or if adverse conditions;

effects of malignant tumours

  • Mechanical pressure & obstruction
  • Tissue Destruction:
    • usual mode of death; infiltrate tissues;
  • Haemorrhage:
    • surface epith. Ca ulcerate; large arteries may be eroded;
  • Secondary infection:
    • ulcerative Ca; obstructed lumens;
  • Starvation:
    • direct by obstructing food intake; malabsorption;
  • Pain:
    • usually late;
  • Haematological disorders:
    • anaemia:
      • bleed; malabs.; marrow replacement;
    • neutrophil leukocytosis common;
  • Cachexia:
    • starvation; infection; liver involvement; serous effusions;
  • Immunologic effects:
    • esp. Hodgkin's, MM, CLL, & terminal cancers;
  • Neuropathic effects:
    • esp. lung, stomach, breast & ovary (without metast. effect!)
  • Myopathic effects:
    • esp. oat-cell lung; breast, colon; visceral → dermatomyositis;
  • Dermatological effects:
    • acanthosis nigrans - stomach, pancreas, lung;
    • recurrent HZ - lymphoma due to decr. cell-med. immunity;
  • Thrombotic complications:
    • thrombophlebitis migrans - pancreas, lung, stomach;
    • Afibrinoginaemia: rare: usually in prostate Ca;
  • Hormonal:
    • own hormones APUD-cell, endocrine tumours
    • non-endo. tumour
      • ACTH (-like) - oat cell; islet-cell; med.thyr.; breast;
      • ADH - oat-cell
      • insulin - mesothelioma, liver;
      • TSH-like - hydat.mole, chorioCa,
      • erythropoietin-like - renal Ca;
  • Hypercalcaemia:
    • extensive osteolytic mets; PGE2; PTH-like;
  • Pulmonary osteoarthropathy:
    • lung, fibrous mesothelioma; (& in ch.supp.dis. lung)
neoplasia.txt · Last modified: 2018/02/02 13:19 by wh