Heterotopic ossification around the lesser trochanter of the femur simulating a malignant lesion. A case report with long-term follow-up and revision of literature.

We report the case of a 28-year-old female who complained of groin pain and restricted range of motion of the hip for the previous two months. A plain radiograph, CT scan and MRI of the pelvis showed a bone mass of uncertain origin around the lesser trochanter, simulating malignancy. An open biopsy was performed to obtain a correct diagnosis. The histological examination excluded a malignant lesion. Two months later, the mass was surgically excised and at follow-up, 9 years after surgery, the patient was completely asymptomatic, without any radiographic sign of recurrence. This is a rare case of heterotopic ossification of the proximal part of the femur, that appeared without any significant trauma or other predisposing risk factors; because the lesion led us to suspect a malignant disease, an open biopsy was needed to make the diagnosis. From an accurate review of the literature, heterotopic ossifications mimicking a malignant lesion that appeared without any predisposing factors are extremely rare.

Pubic osteolysis simulating a malignant lesion. A case report with long-term follow-up.

Pubic osteolysis is a rare pathology characterized by a painful radiographic destructive changes in the pubic rami, pubis or pubic symphysis that often follows a post-traumatic event. The etiology is unclear but it is a benign lesion, frequently misinterpreted as malignant. We report a case of a 54-year-old woman with pubic osteolysis mimicking a malignant lesion, diagnosed after open bone biopsy, conservatively treated without any sequelae and followed-up 10 years after the end of treatment. Although in the majority of the reported cases, a previous trauma has been commonly referred, in our case the patient did not refer to any cause before the onset of clinical symptoms. Knowledge of this entity is important to avoid invasive diagnostic procedures, costly investigations or overtreatment.