The Dubin-Johnson syndrome is a hereditary deficiency in the excretion ofconjugated bilirrubin by hepatocytes characterized by chronic hyperbilirubinemia, alteration in coproporphyrin metabolism, and intracellular deposition of a dark melanin-like pigment giving the liver a typical black cast. We report a 28-year-old male patient who presented conjunctival jaundice and conjugated-hyperbilirubinemia without no other alteration in hepatic biochemistry. The diagnosis of this syndrome was perfomed by using the low-risk methods of laparoscopy-facilitated hepatic biopsy and oral cholecystography In contrast, we avoided the classical Bromsulphalein test because of potential severe side effects. We stress here the current importance of these tests for confirming the diagnosis. By using this methodology, we were not able to quantify the isomeric profile of the urinary coproporphyrins nor 99mTc-HIDA cholescintigraphy. In conclusion, we confirm the utility of hepatic biopsy with the aid of laparoscopy and oral cholecystography for the diagnosis of the Dubin-Johnson syndrome on the basis of their effectiveness and relative lack of complications.

Porphyrias are metabolic disorders of heme biosynthesis, which encompass a broad range of symptoms and signs, neurologic, cutaneous or mixed. Because of lack of specificity and polymorphous clinical picture, porphyrias can mimic either neuropsychiatric, dermatologic, or gastrointestinal diseases. We present the case of a 58 years old man to whom clinical presentation suspicious of Addison\'s disease (melanoderma, fatigue, weight loss, intermittent abdominal pain) was the disguise of porphyria cutanea tarda. A general background of porphyrias and differential diagnosis with other forms of hepatic porphyria, as well as other causes of hyperpigmentation, are given. The clinician should be aware of the protean manifestations of porphyrias and include them in clinical judgment in various situations.

Three cases of erythropoietic protoporphyria are reviewed. The three patients constitute members of one family. The protoporphyrin content of the red blood cells was high, but porphyrins and their precursors in the urine and faeces were not excessive. Other normal members of the family did not reveal high protoporphyrin content in the red blood cells. Clinical symptoms were itching, swelling, shallow depressed scars and waxy yellow discoloration on the face and brown pigmentation and thickness on the back of the hands after exposure to the sun. The microscopic findings from skin biopsy specimens of the lesions resembled changes of the lipoid proteinosis.

BACKGROUND: We evaluated a quality control scheme for the measurement of urinary uroporphyrin, coproporphyrin, total urinary porphyrins and precursors of urinary porphyrins, delta-aminolevulinic acid and porphobilinogen that was performed in The Netherlands during a period of 5 years.
METHODS: Six quality control samples were distributed each year to the participating laboratories. Mean concentrations and the corresponding coefficients of variation were calculated.
RESULTS: Coefficients of variation varied widely and were very high in the concentration ranges that can be found in patients with low-grade porphyria.
CONCLUSIONS: Commutable calibrators are needed to improve the laboratory diagnosis of porphyria.