Calculi and intracellular ochronosis in the submandibular tissues from a patient with alkaptonuria
- 1Department of Human Anatomy & Cell Biology, University of Liverpool, Liverpool, UK
- 2Department of ENT, Gwent Hospital, Newport, UK
- 3Division of Pathology, University of Liverpool, Liverpool, UK
- 4Department of Clinical Chemistry & Metabolic Medicine, Royal Liverpool University Hospital, Liverpool, UK
- Correspondence to Dr A M Taylor, Department of Human Anatomy & Cell Biology, Sherrington Building, Ashton Street, University of Liverpool, Liverpool L69 3GE, UK;
- Accepted 16 September 2009
Alkaptonuria (AKU) is a rare autosomal recessive condition caused by deficiency of the enzyme homogentisate 1,2 dioxygenase, resulting in widespread deposition of oxidised homogentisic acid (HGA) polymer, primarily in joint tissues but also in other connective tissues. Macroscopic pigmentation of connective tissues in AKU is well documented and is the end point of a process that is not understood. Deposition in less common regions may provide clues to the pigment formation process. This is the first report of detection of ochronotic pigment in acinar cells and lumina in the submandibular gland of a patient with AKU. Deposition was noted in the apical region of the cells. A lobar duct presented a large calculus with unusual deposits possibly associated with calcium salts. This report highlights the effect that local and intracellular factors may have on converting HGA into polymeric derivatives in the absence of an extracellular matrix.
Competing interests None.
Ethics approval Obtained from Liverpool Research Ethics Committee.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.