Ligneous Periodontitis in a Patient with Type 1 Plasminogen Deficiency: A Case Report and Review of the Literature

Abstract
Background. Ligneous periodontitis or destructive membranous periodontal disease is a rare condition involving gingival tissues, which is due to plasminogen deficiency and fibrin deposition. Plasminogen deficiency is an ultrarare autosomal recessive disease. The disease is characterized by gingival enlargement and periodontal tissue destruction that leads to rapid tooth loss despite treatment attempts. A defect in fibrinolysis and abnormal wound healing are the main pathogenesis of this condition. It is caused by mutations in PLG, the gene coding for plasminogen, which results in decreased levels and functional activity. Case Presentation. In this case report, clinical and histopathological findings of a 26-year-old male patient who presented with generalized membranous gingival enlargement are presented. He was the third child of consanguineous parents and had multicystic congenital hydrocephalus at birth. Besides the gingival enlargement, he also presented ligneous conjunctivitis since childhood. The intraoral examination revealed generalized periodontal breakdown. Radiographs showed alveolar bone loss present in every quadrant. All blood investigations were normal except for plasminogen deficiency. A biopsy sample was excised from affected gingiva and a series of histopathological evaluation was performed. Based on clinical and histopathological evidence, a diagnosis of destructive membranous periodontal disease or ligneous periodontitis was made. A clinical exome assay for the PLG gene was also done. It was confirmed as Type 1 plasminogen deficiency. Conclusion. Ligneous periodontitis has been rarely reported in India. The reasons could be because of the rarity of the disease or missed diagnosis. The need to take a proper history and perform a proper clinical examination and histopathologic evaluation has to be stressed when diagnosing and treating gingival enlargements. If a genetic condition is suspected, genetic screening is also needed. All these will help the clinician in correctly diagnosing the disease and formulating a proper treatment plan for managing the condition.