Neoplasia

Question 1

What is desmoplasia?

Answer 1

The formation of an abundant collagenous stroma. Some desmoplastic tumors (e.g., some cancers of the female breast) are stony hard or scirrhous.

Question 2

What is a fibroma?

Answer 2

A benign tumor arising in fibrous tissue.

Question 3

What is a chondroma?

Answer 3

A benign cartilaginous tumor.

Question 4

Define adenoma.

Answer 4

The term “adenoma” is applied to benign epithelial neoplasms derived from glands, although they may or may not form glandular structures.

Question 5

Define papilloma.

Answer 5

A papilloma is a benign epithelial neoplasm producing microscopically or macroscopically visible fingerlike or warty projections from epithelial surfaces.

Question 6

Define cystadenoma.

Answer 6

A cystadenoma is a benign epithelial neoplasm that forms a large cystic mass, such as in the ovary.

Question 7

What would you call tumors that produce papillary patterns that protrude into cystic spaces?

Answer 7

Papillary cystadenomas.

Question 8

What is a polyp?

Answer 8

When a neoplasm–benign or malignant–produces a macroscopically visible projection above a mucosal surface and projects, for example, into the gastric or colonic lumen, it is termed a polyp. If the polyp has glandular tissue, it is called an adenomatous polyp.

Question 9

Define sarcoma.

Answer 9

Sarcomas are malignant tumors arising in solid mesenchymal tissues (e.g., fibrosarcoma, chondrosarcoma, leiomyosarcoma, and rhabdomyosarcoma).

Question 10

Malignant neoplasms of epithelial cell origin, derived from any of the three germ layers, are called carcinomas. True or false?

Answer 10

True.

Question 11

What is a squamous cell carcinoma?

Answer 11

A cancer in which the tumor cells resemble stratified squamous epithelium.

Question 12

What is an adenocarcinoma?

Answer 12

A lesion in which the neoplastic epithelial cells grow in a glandular pattern.

Question 13

What is a mixed tumor of the salivary gland?

Answer 13

These tumors contain epithelial components scattered within a myxoid stroma that may contain islands of cartilage or bone. The preferred designation of this neoplasm is pleomorphic adenoma.

Question 14

The great majority of neoplasms, even mixed tumors, are composed of cells from a single germ layer. True or false?

Answer 14

True. An exception is a tumor called a teratoma, which contains recognizable mature and immature cells or tissues belonging to more than one germ cell layer (and sometimes all three). Teratoma originates from totipotential germ cells that are normally present in the ovary and testis.

Question 15

What is an ovarian cystic teratoma (dermoid cyst)?

Answer 15

This form of teratoma differentiates principally along ectodermal lines to create a cystic tumor lined by skin replete with hair, sebaceous glands, and tooth structures.

Question 16

What are hamartomas?

Answer 16

Disorganized but benign masses composed of cells indigenous to the involved site. Once thought to be a developmental malformation unworthy of the -oma designation, many in fact have clonal chromosomal aberrations that are acquired through somatic mutations and on this basis are now considered neoplasms.

Question 17

Define choristoma.

Answer 17

Choristoma is the term applied to a heterotopic rest of cells. For example, a small nodule of well-developed and normally organized pancreatic tissue may be found in the submucosa of the stomach, duodenum, or small intestine.

Question 18

What is anaplasia?

Answer 18

Lack of differentiation. Malignant neoplasms that are composed of poorly differentiated cells are said to be anaplastic. Lack of differentiation, or anaplasia, is considered a hallmark of malignancy. The term anaplasia means “to form backward”, implying a reversal of differentiation to a more primitive level.

Question 19

Define pleomorphism.

Answer 19

Cancer cells often display pleomorphism–variation in size and shape.

Question 20

What are Langhans, or foreign body, giant cells?

Answer 20

Inflammatory cells derived from macrophages and contain many small, normal-appearing nuclei.

Question 21

What is a normal nuclear-to-cytoplasm ratio?

Answer 21

1:4 or 1:6. The nuclei of neoplastic cells are disproportionately large, with a nuclear-to-cytoplasm ration that may approach 1:1.

Question 22

The presence of mitoses necessarily indicates that a tumor is malignant or that the tissue is neoplastic. True or false?

Answer 22

False. Mitoses are simply indicative of rapid cell growth. More important as a morphologic feature of malignancy are atypical, bizarre mitotic figures, sometimes with tripolar, quadripolar, or multipolar spindles.

Question 23

Define metaplasia.

Answer 23

Metaplasia is defined as the replacement of one type of cell with another type. Metaplasia is nearly always found in association with tissue damage, repair, and regeneration. Often the replacing cell type is better suited to some alteration in the local environment.

Question 24

What is meant by the term “dysplasia”?

Answer 24

Dysplasia is a term that literally means “disordered growth”. It is encountered principally in epithelia and is characterized by a constellation of changes that include a loss in the uniformity of the individual cells as well as a loss in their architectural orientation.

Question 25

What constitutes carcinoma in situ?

Answer 25

When dysplastic changes are marked and involve the full thickness of the epithelium, but the lesion does not penetrate the basement membrane, it is considered a pre-invasive neoplasm and is referred to as carcinoma in situ. Once the tumor cells breach the basement membrane, the tumor is said to be invasive.

Question 26

Because benign tumors grow and expand slowly, they usually develop a rim of compressed fibrous tissue called a capsule that separates them from the host tissue. Of what substance is such a capsule comprised?

Answer 26

Such capsules consist largely of extracellular matrix deposited by stromal cells such as fibroblasts, which are activated by hypoxic damage resulting from the pressure of the expanding tumor.

Question 27

What are hemangiomas?

Answer 27

Neoplasms composed of tangled blood vessels. They are often unencapsulated and permeate the site in which they arise (e.g., the dermis of the skin and the liver); when such lesions are extensive, they may be unresectable.

Question 28

Define metastasis.

Answer 28

Metastasis is defined by the spread of a tumor to sites that are physically discontinuous with the primary tumor, and unequivocally marks a tumor as malignant, as by definition benign neoplasms do not metastasize.

Question 29

Give two examples of a malignant tumor that only rarely metastasizes.

Answer 29

1. Glioma (i.e., malignant neoplasm of the glial cells in the CNS) 2. Basal cell carcinoma of the skin

Question 30

What percentage of newly diagnosed solid tumors (excluding skin cancers other than melanoma) present with metastases?

Answer 30

Approximately 30%.

Question 31

What are the three means by which dissemination of cancers may occur?

Answer 31

1. Direct seeding of body cavities or surfaces 2. Lymphatic spread 3. Hematogenous spread

Question 32

Sometimes mucus-secreting appendiceal carcinomas or ovarian carcinomas fill the peritoneal cavity with a gelatinous neoplastic mass referred to as what?

Answer 32

Pseudomyxoma peritonei.

Question 33

What is the most common pathway for the initial dissemination of carcinomas?

Answer 33

Transport through lymphatics. Sarcomas may also use this route.

Question 34

What is "skip metastasis" and how is it possible?

Answer 34

Local lymph nodes may be bypassed--so-called skip metastasis--because of venous-lymphatic anastomoses or because inflammation or radiation has obliterated lymphatic channels.

Question 35

What is a sentinel lymph node?

Answer 35

A sentinel lymph node is defined as "the first node in a regional lymphatic basin that receives lymph flow from the primary tumor". Sentinel node mapping can be done by injection of radiolabeled tracers or colored dyes.

Question 36

Hematogenous spread is typical of sarcomas but is also seen with carcinomas. True or false?

Answer 36

True.

Question 37

Which two organs are most frequently involved in hematogenous dissemination of cancer?

Answer 37

The liver and the lungs. With venous invasion, bloodborne metastatic cells follow the venous flow draining the site of the neoplasm, and the tumor cells often come to rest in the first capillary bed they encounter.

Question 38

What explains the frequent vertebral metastases of carcinomas of the thyroid and prostate?

Answer 38

Cancers arising in close proximity to the vertebral column often embolize through the paravertebral plexus.

Question 39

Which cancers have a propensity for invasion of veins?

Answer 39

1. Renal cell carcinoma often invades the branches of the renal vein and then the renal vein itself, from where it may grow in a snakelike fashion up the inferior vena cava, sometimes reaching the right side of the heart. 2. Hepatocellular carcinomas often penetrate portal and hepatic radicles to grow within them into the main venous channels.

Question 40

Many observations suggest that mere anatomic localization of the neoplasm and natural pathways of venous drainage do not wholly explain the systemic distributions of metastases. True or false?

Answer 40

True. For example, breast carcinoma preferentially spreads to bone, bronchogenic carcinomas tend to involve the adrenals and the brain, and neuroblastomas spread to the liver and bones. Conversely, skeletal muscles and the spleen, despite receiving a high percentage of the cardiac output and having large vascular beds, are rarely the site of secondary deposits.

Question 41

The most common tumors in U.S. men arise from which organs?

Answer 41

Prostate, lung, and colon/rectum.

Question 42

In U.S. women, which cancers are most frequent?

Answer 42

Cancers of the breast, lung, and colon/rectum.

Question 43

What are the common neoplasms of infancy and childhood?

Answer 43

Neuroblastoma, Wilms tumor, retinoblastoma, acute leukemias, and rhabdomyosarcomas.

Question 44

Define neoplasm.

Answer 44

A neoplasm can be defined as a disorder of cell growth that is triggered by a series of acquired mutations affecting a single cell and its clonal progeny.