Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (205 page)

   Laboratory Findings

   Findings of liver function tests may not be abnormal, depending on the type and severity of the disease. In patients presenting with acute fulminant hepatitis, Wilson disease is suggested if there is a disproportionately low serum ALP and relatively mild increase in AST and ALT. ALP is frequently decreased; ALP/bilirubin ratio <2.0 is said to distinguish Wilson disease as cause of fulminant liver failure with S/S = 100%/100%.

   
Radiocopper incorporation
into ceruloplasmin is reduced significantly compared with heterozygotes or normal persons.
⁶⁴
Cu is administered IV or PO and serum concentration is plotted against time. Serum
⁶⁴
Cu disappears within 4–6 hours and then reappears in persons without Wilson disease; secondary reappearance is absent in Wilson disease because incorporation of
⁶⁴
Cu into ceruloplasmin is decreased. Useful when liver biopsy is contraindicated but rarely used since advent of transjugular liver biopsy. Can use mass spectroscopy rather than radioactive Cu.

   Chelating agent (e.g., d-penicillamine) produces urine Cu excretion of 2–4 mg/day.

   Other Considerations

   Diagnosis should be ruled out in any patient with hepatitis with negative serology for viral hepatitis, Coombs-negative hemolysis (due to copper released from necrotic liver cells), or neurologic symptoms to allow for early diagnosis and treatment of Wilson disease.

Suggested Reading

Ferenci P. Diagnosis and current therapy of Wilson disease.
Aliment Pharmacol Ther.
2004;19:157.

TRAUMA

   May be laceration, hematoma, or vascular

   Laboratory Findings

   Core laboratory: Serum LD is frequently increased (>1,400 units) 8–12 hours after major injury. Shock due to any injury may also increase LD. Other serum enzymes and liver function tests are not generally helpful.

*
May principally cause macrovesicular steatosis due to imbalance in hepatic synthesis and export of lipids.

†
May principally cause microvesicular steatosis due to defective mitochondrial function.

‡
May principally cause accumulation of phospholipids in lysosomes.

Chapter
6

Endocrine Diseases

Hongbo Yu

Diabetes Mellitus

Disorders of the Thyroid Gland

Thyrotoxicosis/Hyperthyroidism

Hypothyroidism

Goiter and Thyroid Nodules

Disorders of the Adrenal Gland

Cushing Syndrome

Adrenal Insufficiency

Primary Hyperaldosteronism

Adrenal Masses

Pheochromocytoma

Gonadal Disorders

Gynecomastia

Hirsutism

Galactorrhea

Male Hypogonadism

Disorders of the Pituitary Gland

Hypopituitarism

Pituitary Tumors

Diabetes Insipidus

Syndrome of Inappropriate Antidiuretic Hormone Secretion

Disorders of the Parathyroid Gland and Mineral Metabolism

Hyperparathyroidism

Hypercalcemia

Osteoporosis

This Chapter focuses on six common groups of endocrine disorders based on organ systems: diabetes mellitus, disorders of the thyroid gland, disorders of the adrenal gland, gonadal disorders, disorders of the pituitary gland, and disorders of the parathyroid gland and mineral metabolism. For each organ system, the diseases are further discussed according to clinical presentations and/or laboratory findings. The differential diagnosis, laboratory workup, and radiologic studies for each disease are also considered. Of note, male hypogonadism is covered in the Genitourinary Diseases, Chapter
7
.

General principles in the diagnosis of endocrine diseases include the following: