Psammomatoid Juvenile Ossifying Fibroma of the Mandible – A Histochemical insight!

摘要

Juvenile ossifying fibroma (JOF) are fibro osseous lesions that mostly occur in children. Although a benign entity, JOF is known to be locally aggressive and has a high tendency to reoccur. Two distinctive microscopic patterns have been described; a trabecular variant and a Psammomatoid variant. This latter variant is predominantly a craniofacial lesion and occurs rarely in the jaws. We report a rare case of Psammomatoid Juvenile Ossifying that occurred in the mandible of a young boy along with review of the relevant literature. In addition, the pathology of the lesion was also analyzed with picrosirus red stain and polarizing microscopy Introduction Juvenile Ossifying fibroma is a fibro-osseous entity that arises within the craniofacial bones of young individuals below 15 years of age [1] . Juvenile Ossifying fibroma is a broad term to describe two distinct histopathological variants: Trabacular Juvenile Ossifying fibroma which is distinguished by the presence of trabaculae of fibrillar osteoid and woven bone and Psammomatoid Juvenile Ossifying fibroma (PsJOF) that is characterised by the presence of small uniform spherical ossicles that resemble Psammoma bodies [2] . PsJOF was first reported by Benjamins in 1938, who called the lesion “osteoid fibroma with atypical ossification of the frontal sinus” [3] . Later, Gogl in 1949 reported two cases of what he called “Psammomatoid ossifying fibroma of the nose and paranasal sinus” [4] . In 1952, Johnson termed the same lesion “Juvenile active ossifying fibroma” and described it as a cellular mass which generates innumerable small uniform sized osteoid bodies [5] . Makek in his review of fibroosseous lesions categorized these lesions as Psammous desmo-osteoblastomas [6] . Although PsJOF is an aggressive lesion with a predilection for children in the age range of 5-15 years [7] there are reports where the patient age ranged from 3 months to 72 years [568] A slight male predominance has been observed in several case reports and clinico-pathological studies of PsJOF [2689].Samik El Mofty [2] observed a significant demographic difference between the two variants of Juvenile Ossifying fibroma, while the trabecular variant is predominantly a gnathic lesion, with a predilection for the maxilla, PsJOF occurs overwhelmingly in the sinonasal and orbital bones. Johnson et al [5] and Makek [6] in their case series reports also found that 70% of the PsJoF’s occurred in the Paranasal sinus, 20% in the maxilla and only about 10% in the mandible. Here, we report an additional case of PsJOF that occurred in the mandible an uncommon site for this PsJOF. The histopathology of the lesion was also analysed with the aid of picrosirus red stain and polarizing microscopy to correlate the pathology of the lesion with its clinical behaviour. Case report A 13 year old boy reported to dental clinic of Manipal college of Dental sciences, Manipal in June 2006 with a chief complaint of a swelling on the right side of his face.. The swelling had developed 2 months back, and the size and firmness of the swelling had remained the same since then. An extra Oral examination revealed a 4x 4 cm swelling on the right body of the mandible extending from the angle of the mouth to the inferior body of the mandible (Fig1). The swelling was bony hard in consistency. There was no discharge pus, parasthesia of the lip or restricted mouth opening.