Neoplasms Flashcards
All tumors have two basic components
(1) neoplastic cells that
constitute the tumor parenchyma
(2) reactive stroma made
up of connective tissue, blood vessels, and variable numbers of
cells of the adaptive and innate immune system
classification of tumors and their biological behavior are based
primarily on
parenchymal component, but their growth and
spread are critically dependent on their stroma
desmoplasia
parenchymal cells stimulate the formation of an abundant collagenous stroma
Some desmoplastic tumors—for example, some cancers of the
female breast—are stony hard or scirrhous
Benign Tumors
connective tissue origin a. Arise from the mesoderm b. Examples (1) Lipomas derive from adipose tissue (2) Leiomyomas of the uterus are derived from smooth muscle Unusual tumors that are usually benign
Lipoma Gross/Histo
Gross: Adipose Tissue; well-circumscribed
yellow tumor. Adipose tissue
is connective tissue; therefore
it derives from the mesoderm.
Histology: tumor is composed of benign fat cells with empty spaces
Leiomyomas Gross/Histo
uterus derived from smooth muscle
Gross: The tumor fills the endometrial cavity and distends the uterus. On cross section the benign smooth
muscle tumor has a whorled appearance.
Unusual tumors that are usually
Benign
Mixed tumors
Composed of neoplastic cells that have two different morphologic
patterns, but derive from the same germ cell layer
Not the same as a teratoma
pleomorphic adenoma of the parotid gland
Teratoma
Derive from more than one germ layer—ectoderm, endoderm, and/or
mesoderm (Fig. 9-1 C; Link 9-4); may be benign or malignant
(2) Sites: ovaries (most common site), testes, anterior mediastinum, and pineal gland; tend to have a midline location (pineal gland, anterior mediastinum) or close to the midline (ovaries and testes)
Cystic teratoma
ovary, showing the cystic nature of
the tumor. Hair is present, and
a tooth is visible (arrow). Teratomas can arise from ectoderm, endoderm,
and mesoderm
squamous epithelium (epithelial origin), sebaceous glands (endodermal origin), and cartilage (mesodermal origin)
Malignant tumors (cancer)
- Definition: Characterized by an unregulated proliferation of cells that invade tissue and are
capable of spreading to other sites that are remote from the primary site of origin
What is a Carcinoma?
Derive from epithelial tissue—squamous, glandular, or transitional
epithelium
b. Primary sites for squamous cell carcinoma (SCC) include oropharynx, larynx, upper/ middle esophagus, lung, cervix, penis, and skin. Squamous cell cancers commonly have keratin pearls that stain bright red with a hematoxylin-eosin
Carcinoma Histologic Features
keratin pearls (concentric
layers of eosin-staining keratin
similar to the layers of a pearl).
Squamous cell carcinoma. The many well-differentiated foci of eosinophilic-staining neoplastic cells produce keratin in layers (keratin pearls). Note how squamous epithelium takes up the red eosin stain
Primary sites for adenocarcinoma
a (glandular epithelium) include lung, distal esophagus
to rectum, pancreas, liver, breast, endometrium, ovaries, kidneys, and prostate
Adenocarcinomas commonly have glands with secretions in the lumen
Adenocarcinoma histology
glands lined by neoplastic glandular cells with hyperchromatic and irregular nuclei, and a gland lumen with the material in the lumen. G, Adenocarcinoma.
Irregular glands infiltrate the stroma. The nuclei lining the gland lumens are cuboidal and contain nuclei with hyperchromatic nuclear chromatin.
Glandular cells appear to pile up on each other. Many of the gland lumens contain secretory material (arrow).
Primary sites for transitional cell carcinoma
urinary bladder, ureter, and
renal pelvis
Sarcomas
Derive from connective tissue (mesoderm origin)
b. Approximately 40% of sarcomas are located in the lower extremity.
c. Examples include those that arise from bone (osteosarcoma); and skeletal muscle (rhabdomyosarcoma; see also Link 24-23 A, B)
Osteogenic Sarcoma
The light-colored mass of tumor in the metaphysis abuts the epiphyseal plate and has spread laterally out through the cortex and into the surrounding tissue
Rhabdomyosarcoma
Gross: the tumor has a fleshlike appearance
Histology: the tumor is composed of elongated cells that resemble fibroblasts.
Hamartoma
Nonneoplastic overgrowth of disorganized tissue that is indigenous to a particular site
Examples: bronchial hamartoma (contains cartilage, Peutz-Jeghers (PJ) polyp (contains glandular tissue)
Hamartoma of lung
composed of cartilaginous tissue
Choristoma (heterotopic rest)
a. Definition: Mass of non-neoplastic tissue that is located in a foreign place
b. Examples: pancreatic tissue in the wall of the stomach (Link 9-7), brain tissue in the nasal cavity, functioning thyroid tissue in the liver (Link 9-8)
Heterotopic pancreatic tissue
the stomach wall is composed of pancreatic ducts and rare acini interspersed among smooth
muscle bundles.
Parenchyma
Neoplastic component of a tumor that determines its biological behavior