Histology and classification of neolasms

Question 1

What is a neoplasm?

Answer 1

An abnormal tissue mass due to excessive uncontrolled growth of transformed cells which is uncoordinated with the normal tissue.

Question 2

What are malignant neoplasms known as?

Answer 2

Cancer

Question 3

What is neoplasia?

Answer 3

New and uncontrolled growth of cells due to disturbed cell proliferation, differentiation and an abnormal relationship with surrounding tissue

Question 4

What is the “true” definition of tumour?

Answer 4

While colloquially used as a synonym for cancer it strictly means swelling and these swellings can be due to many things such as cysts, haemorrhage, inflammation, granuloma, malformations/congenital anomalies as well as neoplasms

Question 5

How can it be determined if an abnormal mass is or isn’t a neoplasm?

Answer 5

This requires a specimen, cytology is the fastest and simplest procedure where cells are obtained through fine needle aspiration, tapping of fluid collections through a needle, brushings through an endoscope or by direct scrapings
Whole tissues can be obtained through biopsy

Question 6

Why is it important to classify neoplasms?

Answer 6

Precise classification of a neoplasm is essential to aid diagnosis in order to plan appropriate/correct treatment as different neoplasms can have different biological and clinical features

Question 7

What are the features of neoplastic cells?

Answer 7

Abnormal cell proliferation, abnormal cell differentiation and an abnormal relationship with the surrounding stroma

Question 8

What is the abnormal relationship with stroma seen in neoplasms?

Answer 8

Transformed cells can invade and metastasise to other body regions
Other, normal stromal cells such as blood vessels may have been recruited

Question 9

What does it mean if a mass is palpable?

Answer 9

It may feel hard (scirrous) or soft (medullary)

Question 10

What is the difference between exophytic and endophytic growth?

Answer 10

Exophytic growth is when a neoplasm grows on top of the surfaces such as polyps while endophytic growths grow into the tissue and may be papillary, a heaped mass or encircle the tissue

Question 11

What is the implication of a palpable tumour having scirrous?

Answer 11

This hard gritty feeling may be due to reactive changes in the stroma where the tumour is causing a desmoplastic reaction where there is proliferation of non-neoplastic connective tissue and focal dystrophic calcification

Question 12

What are the clinical implications of microcalcifications in scirrotic tumours?

Answer 12

They can be detected by tools such as mammograms which can lead to early detection of cancer
Dangerous scirrous can usually be distinguished as they are irregular and fine while unsuspicious ones are regular, more punctiform and coarse and chunky

Question 13

What are the characteristics of benign neoplasms?

Answer 13

Slow growing, few mitoses, resemble tissue of origin, nuclear morphology normal, usually well circumscribed or encapsulated, necrosis is rare, ulceration is rare, they never invade or metastasise

Question 14

What are the characteristics of malignant neoplasms?

Answer 14

They have variable to rapid growth and variable to many mitoses, variable to poor resemblance to tissue of origin, nuclear morphology is abnormal, often poorly defined or irregular, necrosis is common, ulceration is common, many invade surrounding tissues, may metastasise

Question 15

What is a tumour type?

Answer 15

A term which describes the presumed cell of origin of a neoplasm as the tumour often has histological features similar to that tissue

Question 16

What are the histological types?

Answer 16

Epithelial, stromal and haemopoietic/lymphoid

Question 17

What does anaplastic mean?

Answer 17

When a neoplasm is very poorly differentiated and does not resemble any normal tissue
These are always malignant

Question 18

What tissue of origin does the adeno prefix indicate?

Answer 18

Glandular epithelium

Question 19

What tissue of origin does the papillo prefix indicate?

Answer 19

Non-glandular epithelium

Question 20

What tissue of origin does the lipo prefix indicate?

Answer 20

Fat

Question 21

What tissue of origin does the osteo prefix indicate?

Answer 21

Bone

Question 22

What tissue of origin does the chondro prefix indicate?

Answer 22

Cartilage

Question 23

What tissue of origin does the angio prefix indicate?

Answer 23

Blood vessel

Question 24

What tissue of origin does the rhabdo prefix indicate?

Answer 24

Skeletal muscle

Question 25

What tissue of origin does the leiomyo prefix indicate?

Answer 25

Smooth muscle

Question 26

What does the suffix oma indicate about a tumour?

Answer 26

Used to indicate an epithelial or stromal tumour which is benign

Question 27

What does the suffix carcinoma indicate about a neoplasm?

Answer 27

Used to indicate an epithelial malignant tumour

Question 28

What does the suffix sarcoma indicate about a neoplasm?

Answer 28

Used to indicate a stromal malignant tumour

Question 29

What tumour types are exceptions to the naming conventions?

Answer 29

Melanoma is a malignant tumour of melanocytes but the suffix indicates a benign tumour
Haematopoetic/ Lymphoid tumoursare also exceptions with leukaemia being a malignant neoplasm of haematopoietic cells, all lymphomas are malignant neoplasia of lymphoid cells, multiple myeloma is malignant neoplasm of plasma cells in bone marrow

Question 30

What can occur to normal haematopoiesis in leukaemia?

Answer 30

Leukaemic cells replace or suppress normal hematopoiesis resulting in a lack of normal leukocytes (granulocytopenia) increasing the risk of infection, a lack of platelets (thrombocytopenia) and the risk of haemorrhage as well as anaemia due to a lack of red blood cells

Question 31

What is acute myelogenous leukaemia?

Answer 31

Where there is an abnormal number of abnormal white blood cells, red blood cells and/or platelets

Question 32

What is chronic myelogenous leukaemia?

Answer 32

Neoplasm Associated with the Philadelphia chromosome (a reciprocal translocation between chromosome 9 and 22)

Question 33

What is acute lymphocytic leukaemia?

Answer 33

This is where white blood cells do not fully mature and cannot function properly, these immature cells are referred to as blasts and are typically observed in children rather than adults

Question 34

What is chronic lymphocytic leukaemia?

Answer 34

Where abnormal B cells accumulate due a decrease in rate of loss due to abnormal apoptosis, this is mostly observed in adults

Question 35

What is a lymphoma?

Answer 35

Proliferation of neoplastic lymphoid cells in the lymph nodes such as hodgkins disease

Question 36

What are the clinical features of small lymphocytic lymphoma?

Answer 36

Seen in older adults, it is essentially the solid tissue (lymph node) component of chronic lymphocytic leukaemia

Question 37

What are the clinical features of diffuse large B cell lymphoma?

Answer 37

Most common type, seen in adults, often involves multiple lymph nodes, course is indolent with prolonged survival

Question 38

What are the clinical features of burkitts lymphoma?

Answer 38

Endemic in Africa with mandibular and abdominal involvement; affects mainly children and young adults

Question 39

What are the clinical features of high grade B cell lymphoma?

Answer 39

Sporadic; may be seen with HIV infection

Question 40

What are the clinical features of precursor T or B cell lymphoblastic lymphoma?

Answer 40

Seen in children and adolescents; very aggressive and can progress to acute lymphocytic leukemia

Question 41

What are the clinical features of mantle cell lymphoma?

Answer 41

Seen in adults in middle age; often advanced at diagnosis and may be extranodal including multifocal submucosal nodules in bowel

Question 42

What are the clinical features of marginal zone lymphoma?

Answer 42

Seen in middle aged adults; typically arises in areas of immune activation similar lesions associated with mucosal lymphoid tissue are called mucosa-associated lymphoid tissue tumours

Question 43

What occurs in multiple myeloma?

Answer 43

A malignant neoplastic proliferation of abnormal plasma cells which accumulate in the bone marrow, this results in bone lysis due to activation of oesteoclasts because of over expression of receptor activator for nuclear factor kappa B ligand. These lytic lesions are characteristic and can produce bone pain. This also results in hypercalcemia which in addition to the aberrant immunoglobulin produced results in renal failure

Question 44

What are blastomas?

Answer 44

Neoplasms which occur exclusively in children less than 5 years old, the term comes from blast cells which are precursors of mature cells in a tissue so the neoplasms resemble primitive embryonic blast tissues

Question 45

What are examples of blastomas?

Answer 45

Retinoblastoma, nephroblastoma, hepatoblastoma and neuroblastoma

Question 46

What are germ cell tumours or teratomas?

Answer 46

These are the abnormal development of pluripotent adult germ cells or early embryonic germ cells because of this teratomas often consist of cell types derived from all three germ cells (endoderm, ectoderm and mesoderm)

Question 47

How do teratomas of embryonic origin occur?

Answer 47

Congenital defects during the maturation and migration of germ cells to the gonads, they are found in the fetus in the midline (brain, skull, nose, tongue, neck, mediastinum, retroperitoneal, coccyx as well as the gonads

Question 48

How do teratomas in adult life occur?

Answer 48

These are derived from germ cells such as oocytes and spermatocytes causing the teratoma to be located in the testes or ovaries. Ovarian teratomas are often benign and are called dermoid cysts, seminoma is a male germ cell teratoma found in adult life