V542 Lab #5: Malignant Neoplasms

Flashcards covering general neoplasia principles, histological criteria of benign versus malignant neoplasms, and pathology slides of squamous cell carcinoma, adenocarcinoma of the rectum, ocular malignant melanoma, and scirrhous breast carcinoma.

In a neoplasm, what do the parenchymal cells represent?

They represent the proliferating cell line from the organ that gave rise to the lesion, and are considered the actual "tumor" cells.

What is the biological nature of a neoplasm's stroma, even in a malignant neoplasm?

The stroma is benign fibro-connective tissue and vascular elements that the tumor uses to grow on.

What are the two principal criteria of cancer?

(1) Anaplasia and (2) evidence of invasion of normal tissues or spread to distant sites (metastasis).

What does the term anaplasia imply regarding cells and tissue?

A backward form, primitive, or more embryonic appearance of the cells and tissue.

What does marked pleomorphism refer to in anaplastic tumor cells?

Variation in cell size and shape.

What characteristic nuclear features are typically seen in anaplastic cells?

Hyperchromasia, enlarged size compared to normal counterparts, prominent nucleoli, and a lopsided nucleus-to-cytoplasm ratio favoring the nucleus.

How do benign and malignant neoplasms typically differ with respect to encapsulation and mitotic cells?

Benign tumors are frequently encapsulated and have rare mitotic cells, whereas malignant tumors lack a capsule and often present with abundant and abnormal mitoses (tripolar or quadrapolar).

How is a teratoma defined?

An either benign or malignant tumor of germ tissue (generally reproductive tissue, i.e., ovary or testis) composed of more than one germ line.

What is a sarcoma?

A malignant tumor of mesenchymal cell origin.

How do a carcinoma and an adenocarcinoma differ by definition?

A carcinoma is a generic term for a malignant tumor of epithelial cell origin, whereas an adenocarcinoma is a generic term for a malignant lesion of glandular tissue origin.

In skin pathology, how are acanthosis and hyperkeratosis defined?

Acanthosis is a greatly thickened epidermis, while hyperkeratosis is an overgrowth of the keratin layer of the epidermis.

What structure is considered the histological hallmark of squamous cell carcinoma (SCC)?

Keratin pearls (squamous cells arranged in a concentric circle producing keratin on the inside).

What histological feature of squamous cell carcinoma is highlighted in this image?

A keratin pearl, surrounded by nests of tumor cells.

What is the hallmark growth pattern characteristic of adenocarcinoma of the rectum?

The gland-within-gland pattern, where glands are arranged very closely with no intervening connective tissue stroma (lamina propria).

What characteristic adenocarcinoma architectural pattern is demonstrated in this microscopic view?

Gland-within-gland pattern (closely arranged malignant glands lacking intervening stroma).

In malignant melanoma of the eye, which cell shape is associated with a poorer prognosis?

Epithelioid cell types (which are more rounded/oval-shaped and appear more primitive).

How are spindle-type melanoma cells morphologically described?

They are longer and tapered at the ends.

What two cell morphologies of ocular melanoma are shown side by side in this histological section?

Epithelioid cells on the left and spindle cells on the right.

A patient presents with blurred vision, flashes of light, floaters, a visual field defect, and this dome-shaped elevation behind the retina. What is the working diagnosis?

Choroidal melanoma (malignant melanoma of the eye).

What percentages of breast carcinomas arise from ductal versus lobular epithelium?

$90\%$ arise from ductal epithelium and $10\%$ arise from lobular epithelium.

What bimodal age pattern of incidence is observed in breast cancer?

A peak in women in their late 20s and early 30s, and another peak among women of menopausal age.

What are the infiltrating and noninfiltrating forms of breast carcinoma arising from ductal epithelium?

Infiltrating is scirrhous carcinoma (the most common form, accounting for $75\%$ of breast carcinomas) and noninfiltrating is intraductal carcinoma.

What does "in-situ" signify in in-situ lobar carcinoma of the breast?

Noninfiltrating tumor cells that are still attached to a basement membrane.

What is the desmoplastic response observed in scirrhous carcinoma?

A dense fibrous stromal overgrowth where excess collagen fibers stain pink, appear acellular, and resemble cotton candy.

Histologically, how are "soldier file tumor cells" distinguished from "compressed ducts" in scirrhous carcinoma of the breast?

Soldier file cells form a single strand/cord of tumor cells, whereas compressed ducts consist of two rows of cells stacked together.

What two cellular patterns of scirrhous carcinoma of the breast are pointed out in this slide?

Compressed ducts (two rows of cells stacked together) and soldier file cells (single-strand cords of tumor cells).