A 60-year-old female presented with a 20-year history of progressive dark bluish discoloration of skin and passage of dark colored urine, painful arthritis and a recent history of invasive ductal carcinoma of right breast. Skin biopsy revealed hyaline material which was Periodic-Acid-Schiff stain positive and Congo-red stain negative, urine analysis revealed dark urine with presence reducing substance and radio-imaging showed intervertebral ossification and joint ankyloses. The patient was managed symptomatically with physiotherapy and acetaminophen on as required basis. This image is reported as a classic case of Alkaptonuria with clinical, histopathological and radio-imaging findings and the presence of invasive ductal breast carcinoma in the same patient.

The urine of patients with alkaptonuria turns dark brown due to the oxidation of homogentisic acid (HGA) to benzoquinone acetic acid (BQA), and this is accelerated by the addition of alkali. We recently reported that alkaptonuric urine and HGA after the addition of alkali showed characteristic peaks at 406 and 430 nm. In order to improve the sensitivity of our spectrometric method for the detection of HGA, we accelerated the oxidation of HGA to BQA using sodium hypochlorite pentahydrate (NaOCl·5H2O), which is a strong oxidant. In the present study, we measured the absorption spectra of alkaptonuric urine and HGA solution after the addition of sodium hydroxide (NaOH) or NaOH with NaOCl·5H2O and analyzed the oxidation reaction of HGA after alkalization using a liquid chromatography time-of-flight mass spectrometer (LC/TOF-MS) and nuclear magnetic resonance (NMR) spectrometry. We accelerated the oxidation of HGA to BQA by adding NaOH with NaOCl·5H2O, and this absorbance measurement was useful for more sensitively observing the oxidation of HGA than LC/TOF-MS and NMR spectroscopy. This quick and easy screening method may be suitable for the diagnosis of alkaptonuria.

Ochronosis is the bluish-black discolouration of connective tissue, including heart valves, joints, kidney and the skin. It is due to the deposition of homogentisic acid (HGA) commonly found in alkaptonuria. Ochronosis in the aortic valve is a rare occurrence and there is limited data available on the most appropriate choice of valve prosthesis in these patients. This case involves a 72-year-old male with symptomatic aortic stenosis and on echocardiogram a severe calcific trileaflet aortic stenosis with normal ejection fraction. Intraoperative aortic cannulation was routine and uncomplicated, and bluish-black discolouration of aortic valve was noted. Thorough decalcification was undertaken and a bioprosthetic valve was chosen in accordance with patient's age and preference. There were no complications post-operatively and the patient reported being well. Ochronosis affecting the aortic valve is a rare condition and there is limited data on the recurrence rate as well as the natural history of the disease. This case reports aims to provide data to facilitate further research to better understand the natural history of aortic valve ochronosis and rates of recurrence following bioprosthetic aortic valve replacement (AVR).