Kaposi sarcoma

Also known as KS or multiple idiopathic pigmented hemangiosarcoma.

This is an AIDS-defining illness.
The name 'sarcoma' is a misnomer because a sarcoma should arise from mesenchyme tissue. The histogenesis of KS is unknown, but it is speculated to begin in lymphatic endothelial tissue.

 

Pathogenesis

• Human herpesvirus 8 (HHV-8) can establish lifelong infections in hosts.
• HHV-8 is an oncovirus. An oncoviral infection is sufficient to cause healthy tissue to become cancerous (oncogenesis). However, HHV-8 is rarely oncogenic in immunocompetent patients, due to immune system activity.
• In patients with immunosuppression, HHV-8 can activate oncogenes in infected cells.
• Highly vacular tumours form at sites of oncogenesis.

 

Risk factors 

• AIDS
• Post-transplant immunosuppression

 

Signs

Distribution

• Usually on the lower limbs, especially the toes and soles of the feet

Colouration:

• Red
• Violet
• Blue
• Black

Morphology: 

• Macule: flat area of altered colour, <1.5cm in diameter
• Patch: flat area of altered colour, >1.5cm in diameter

• Papule: solid raised palpable lesion <0.5cm in diameter
• Nodule: solid, raised, palpable lesion, >0.5cm in diameter
• Plaque: palpable, flat lesion, usually >1cm in diameter, most are raised, but some may just be thickened without being visibly raised, its borders may be well defined or poorly defined

VIPoma

This is a type of pancreatic cancer called a pancreatic neuroendocrine tumour (PNET).
These originate in the pancreatic islets.

Follicular thyroid cancer

This is the second most common thyroid cancer (about 15% of cases).

Papillary thyroid cancer

This is the most common thyroid cancer (75-85% of cases).

Anaplastic thyroid cancer

This is a rare thyroid cancer.
It has a poor prognosis.

Carcinoid tumour

This is a neoplasm which arises from neuroendocrine cells, particularly enterochromaffin cells in the gastrointestinal tract.

A carcinoid can secrete many hormone-like substances, commonly serotonin and kallikrein. This can result in carcinoid syndrome. This is an example of a paraneoplastic syndrome. 

Parathyroid adenoma

This is a neoplasm of the parathyroid glands.
There is usually excessive production of parathyroid hormone (PTH) resulting in hyperparathyroidism. 

Small cell lung cancer

Also known as SCLC or small-cell carcinoma of the lung.
It accounts for 10% to 15% of lung cancers.

 

Complications

• SCLC can secrete anti-diuretic hormone (ADH, vasopressin) causing SIADH. This is an example of a paraneoplastic syndrome.
• SCLC can trigger the production of autoantibodies, causing Lambert–Eaton myasthenic syndrome.

Gastrinoma

This is a type of pancreatic cancer called a pancreatic neuroendocrine tumour (PNET).
These originate in the pancreatic islets.


Gastrinoma refers to a gastrin secreting neoplasm.
It causes pancreatic ulcerogenic tumor syndrome, also known as Zollinger-Ellison syndrome.

Invasive ductal carcinoma

This is the most common form of breast cancer (about 55% of cases).

See also

• Ductal carcinoma in-situ (DCIS)

Ductal carcinoma in situ

This is a premaligant change which can progress to invasive breast cancer.

 

See also

• Invasive ductal carcinoma

Paget's disease of the breast

This is a consequence of invasive breast cancer.

 

Symptoms and signs

• Itchy, erythematous rash (similar to eczema) over the areola and nipple

Hepatocellular carcinoma

This is the most frequent liver cancer (about 75% of cases).
It is a type of chronic liver disease. 

 

Risk factors

• Chronic viral hepatitis
• Aflatoxin poisoning
• Chronic hepatitis
• Cirrhosis

Urothelial carcinoma

Also known as transitional cell carcinoma.

This is the most frequent bladder cancer (about 95% of cases).

Risk factors 

• Exposure to carcinogens, e.g. in the textile dyeing industry

Renal cell carcinoma

Also known as RCC. 
This is the most frequent kidney cancer (about 90-95% of cases).

Non-small cell lung cancer

Also known as NSCLC.
It accounts for 80% to 85% of lung cancers.

Prostate adenocarcinoma

This is the most frequent prostate cancer (over 99% of cases).

Pituitary adenoma

Physiology

•   See: Pituitary gland and the hypothalamus 

 

Pathophysiology

• The neoplasm occupies space in the skull and may raise intracranial pressure. 
• The neoplasm may compress the optic chiasm, blocking signal propagation from the lateral retinal cells.

 

• Neoplasia of pituitary cells may cause hyperpituitarism (excessive pituitary activity). 
• Adenoma may produce excessive human growth hormone (hGH):  Pituitary gigantism (before closure of the growth plates). Acromegaly (after closure of the growth plates). 
• Adenoma may produce excessive prolactin: Unexpected lactation (in women or men).
• Adenoma may produce excessive cortisol: Hypercortisolism (Cushing's disease).

• Compression of normal pituitary cells may cause hypopituitarism (insufficient pituitary activity).
• Adenoma may disrupt human growth hormone (hGH) production: Pituitary dwarfism.
• Adenoma may disrupt prolactin production: Failure to lactate.
• Adenoma may disrupt production of follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH): Infertility.
• Adenoma may disrupt cortisol production: Hypocortisolism (Addison's disease).  

 

Symptoms and signs

• Headache (various types, various mechanisms)
• Visual field defects, classically bitemporal hemianopia (optic chiasm compression)

• Hyperpituitarism
• Gigantism
• Acromegaly
• Unexpected lactation (in women or men) 

• Hypopituitarism
• (Proportional) dwarfism
• Oligo- or amenorrhoea 
• Infertility 
• Failure to lactate

Phaeochromocytoma

A phaeochromocytoma is a neoplasm of the adrenal medulla.

 

Pathophysiology

This produces excessive catecholamines, mostly norepinephrine and a significant amount of epinephrine.
The adrenergic signalling results in sympathetic nervous system hyperactivity. 

 

Symptoms and signs

• Secondary refractory hypertension
• Sinus tachycardia 
• Heart palpitations
• Chest pain 
• Anxiety
• Sweating 

Seminoma

This is a type of testicular cancer.
40 to 45% of testicular cancers are seminomas.