Page 571 - Concise Pathology for Exam Preparation ( PDFDrive )

556 SECTION II Diseases of Organ Systems

(c) Occasionally, may be a part of MEN-1 syndrome (multiple endocrine neoplasia
Type I).
(d) Microscopically, tumour cells are arranged in trabeculae and resemble the cells of
zona fasciculata. In a few cases, tumour cells may resemble the cells of zona glo-
merulosa or reticularis.
2. Adrenocortical carcinoma
(a) Rare, can occur at any age including childhood.
(b) More likely to be functional than adenomas.
(c) Large invasive lesions, many exceeding 20 cm in diameter.
Cut surface
• Variegated shows haemorrhage, necrosis and cystic change.
• Invasion of contiguous structures including adrenal vein and inferior vena cava is com-
mon. Median survival is two years.
Microscopy
Cells vary from being well differentiated (resembling adenoma cells) to bizarre monstrous
giant cells.

Q. Write briefly on the clinicopathological features and laboratory
diagnosis of pheochromocytomas.
Ans. Pheochromocytomas are
• Uncommon neoplasms composed of chromaffin cells, which synthesize and secrete
catecholamines
• Important because they cause surgically correctable hypertension
• Associated with rules of ‘10’. Ninety percent arise from adrenal medulla, 10% from extra-
adrenal tissue (those developing in extra-adrenal paraganglia are called paragangliomas)
• Known to be associated with, MEN-IIA, MEN-IIB and von Hippel–Lindau syndromes,
as well as von Recklinghausen disease and Sturge–Weber syndrome (Germline muta-
tions in RET, NF1, VHL and succinate dehydrogenase complex subunit or SDHB, SDHC
and SDHD genes)
• Ten percent of sporadic adrenal pheochromocytomas are bilateral and 10% are malignant.

Histology

• Polygonal to spindle-shaped chromaffin cells arranged in small nests (Zellballen pattern) or
alveoli along with their supporting cells. They are separated by a rich vascular network.
• Finely granular cytoplasm (seen better with silver stain)
• Variable cellular and nuclear pleomorphism; mitotic figures are rare.
• Capsular and vascular invasion may be seen in benign lesions also; a diagnosis of
malignancy is exclusively based on the presence of metastasis.

Clinical Course
• Abrupt increase in blood pressure with palpitations, headache, vomiting, sweating,
tremors and a sense of apprehension. In two-thirds of patients, hypertension is chronic
and sustained.
• Paroxysms are precipitated by stress.
• Cardiac complications include congestive cardiac failure, pulmonary oedema, myocardial
infarction, cerebrovascular accidents, myocardial instability and arrhythmias.

Laboratory Diagnosis
Increased urinary excretion of free catecholamines and their metabolites, eg, vanillylman-
delic acid (VMA) and metanephrines, is typically seen.
Q. Define and classify diabetes mellitus (DM). Describe its
pathogenesis, clinical features and complications.

Ans. As per WHO, DM is a heterogeneous metabolic disorder, characterized by chronic
hyperglycaemia with disturbance of carbohydrate, fat and protein metabolism.

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