Clinical information: This 50-year-old man was admitted to the hospital because of a 20 pound weight loss over the preceding three months. He also complained of a persistent cough which had recently increased in severity and which was occasionally productive of blood-tinged sputum. The patient admitted to smoking two packs of cigarettes a day since the age of 19. A chest X-ray showed a density in the right central (perihilar) lung field. Smears prepared from a three day pooled sputum specimen and stained by the Papanicolaou technique (Pap stain) were positive for malignant cells. Mediastinoscopy failed to identify evidence of mediastinal lymph node metastases. A right pneumonectomy was performed.

Gross Pathology: Examination of the right lung showed dense, fibrous adhesions involving the visceral pleura of the medial aspect of the upper lobe. An indurated mass was palpated beneath the area of the pleural adhesions. On cut section this mass was gray-tan, firm, and infiltrated the surrounding lung parenchyma in a fan-like fashion. Dissection of the bronchial tree revealed gradual narrowing and ultimate complete destruction of the proximal upper lobe segmental bronchus by the same mass, which also appeared to infiltrate the bronchial wall. The bronchial divisions distal to the lesion were dilated and plugged with mucus while the lung parenchyma supplied by these divisions was non-crepitant. Enlarged lymph nodes were found in the hilus. Cross sections through these nodes showed that they were replaced by tissue identical to that comprising the upper lobe mass.

Microscopic Pathology: - Transition from normal pseudostratified columnar epithelium to squamous epithelium (squamous metaplasia) in the involved bronchus. - Progressive disorganization of metaplastic squamous pattern from epithelial dysplasia to carcinoma-in-situ to frank invasive epidermoid (squamous cell) carcinoma. - Epidermoid carcinoma is characterized by the abnormal squamous epithelium projecting downward into the underlying bronchial wall and into peribronchial lymphatic channels. - The tumor shows intercellular bridges and scattered areas of keratin formation consisting of pink material arranged in concentric layers (squamous "pearls").

Questions:
1. What are some other risk factors, besides tobacco smoking, associated with the pathogenesis of bronchogenic carcinoma?
2. What significant change has occurred in recent years concerning the incidence of bronchogenic carcinoma among women?
3. Where within the lung does epidermoid carcinoma most commonly occur? (Central? Peripheral zone?) Adenocarcinomas?

Clinical Information: A 62 year old woman had progressively worsening constipation for several months, with decrease in the caliber of the stools, cramping, abdominal pain, increased fatigability and a 4 kg weight loss. Obstipation finally prompted her to seek medical attention. Physical examination: The patient was a thin, anxious woman who appeared older than her stated 62 years. Rectal examination demonstrated external hemorrhoids, stools that were 3+ positive for blood and no masses. Two attempts at sigmoidoscopy were unsuccessful when the instrument could not be passed into the sigmoid colon.

Positive laboratory findings included Hemoglobin = 7.3 (normal = 12-16) gm/dl; Hematocrit = 25 (Normal = 38-47) %. The erythrocytes were microcytic and hypochromic on the peripheral smear.

Gross Pathology. She underwent surgery with resection of a 30 cm segment of rectosigmoid colon. On opening the specimen, a fungating lesion was seen at the point where the sigmoid colon joined the rectum, the lesion invaded circumferentially creating a "napkin-ring" appearance.

Microscopic Pathology: - The normal colonic epithelium adjacent to the tumor contains one continuous layer of goblet cells with the nucleus oriented at the base of the cells. - The normal cells rest on a continuous basement membrane. - The cells of the malignant neoplasm have lost their mucin secreting ability and are arranged in haphazard glands and cords. - These groups of malignant cells have traversed the muscularis propria and invaded the muscular layer of the colon. The serosa is intact. - The individual cells show pleomorphism, hyperchromatism, increased N/C ratio, prominent nuclei, and thickened nuclear membranes.

Questions:

1.Discuss the frequency of carcinomas in the right and left colon.
2. Compare the pathological and clinical features of right-sided tumors with those of left-sided ones.
3. Discuss the use of stool for occult blood as a screening tool for detection of colorectal carcinomas.
4. State the significance of colorectal polyps in the pathogenesis of colorectal carcinomas.

Clinical Information: A 45 year old woman had a six month history of gradually increasing lower abdominal discomfort, which seemed to intensify before her menstrual periods. Her periods had become increasingly irregular over the last year. The pain was dragging in character and radiated into the groin area bilaterally. Physical examination revealed an asymmetrically enlarged uterus. After further work-up a hysterectomy was performed.

Gross Pathology: The specimen consisted of a uterus that measured 15 (normal mean = 8) cm in length and was distorted by an expansion of the posterior surface of the fundus. This area was firm and multinodular. On cut section the posterior wall of the fundus was widened by a whorled, fibrous, and fleshy appearing, pink-tan mass that showed foci of cystic necrosis. The wall measured up to 5 (normal mean = 3) cm in thickness.

Microscopic Pathology: - Tumor is composed of bands of tumor cells separated by large areas of necrosis. - Tumor cells are spindle-shaped with small amount of cytoplasm and pleomorphic and hyperchromatic nuclei. - Note the unusual mitotic figures.

Questions
1. Name the cell line from which sarcomas are derived.
2. Describe the usual biological behavior of leiomyosarcomas.
3. What microscopic feature represents the single most reliable criterion for predicting the behavior of leiomyosarcomas?
4. Name the two organ systems in which both benign and malignant smooth muscle tumors often occur.

Clinical Information: This lymph node is from a radical neck dissection (an operation to remove multiple metastases to the lymph nodes of the neck) in a 75-year-old man, four months following x-ray treatment of a squamous carcinoma of the soft palate. Many firm lymph nodes were identified in the gross specimen. The mass from which these sections were taken measured 4.5 cm in diameter, and was found beneath the sternocleidomastoid muscle.

Questions:
1. What type of cells, foreign to the lymph nodes, can you identify?
2. How did these cells arrive in the node?
3. Which specific criterium(a) decides that these foreign cells are malignant?