Bizarre Parosteal Osteochondromatous Proliferation of the Second Metatarsal Bone (Nora's Lesion)

Unusual Presentation of Bizarre Parosteal Osteochondromatous Lesion of the Second Toe (Nora’s Lesion)

“…3 It is a rare benign neoplasm usually seen in young adults, although it has been noted in other age groups. [2][3][4][5] The exact epidemiology of the occurrence of this lesion in the lower extremity is not known. Usually, this lesion involves the proximal shafts of the phalanges, the metacarpals, and metatarsals (76% involving the hand, 56% involving the hand, and 20% involving the foot, respectively) 6 as well as lesions in long bones (27%) and less frequently in femur, tibia, humerus, fibula, radius, and skull.…”

“…Usually, this lesion involves the proximal shafts of the phalanges, the metacarpals, and metatarsals (76% involving the hand, 56% involving the hand, and 20% involving the foot, respectively) 6 as well as lesions in long bones (27%) and less frequently in femur, tibia, humerus, fibula, radius, and skull. [1][2][3][4][5][6][7][8][9] The cause of BPOP is unknown, although it may be related to trauma. One hypothesis suggests that there is a continuum among florid-reactive periostitis, BPOP, and Turrets exostosis, 10,11 whereas some authors relate it to myositis ossificans and the so-called fibroosseous pseudo-tumor of the digits.…”

“…7 It is highly possible that a traumatic insult may be simply not recalled by the patient, as in the present case. [1][2][3][4][5][6][7] The typical clinical characteristic of this tumor is lack of pain at rest as well as palpation. 9 The mass grows slowly and manifests itself with discomfort rather than pain, and rarely is there any erythema or discoloration in the overlying skin.…”

“…Typically, BPOP is a well-marginated mass of heterotrophic mineral arising from the cortical surface of the affected bone. 2,6,15,16 There is little alteration in the underlying bone, although in some cases it is ill defined. There is no periosteal reaction, flaring, or osteolysis of the cortex.…”

“…arosteal tumors involving the small bones of the feet are rare and account for only 2% of all tumors of the feet. 1,2 Their clinical and imaging features often imitate other tumor and tumor-like conditions. Megadactyly in such a setting is still rarer, adding to the surgeon's dilemma.…”