Aneurysmal bone cyst: An unusual presentation of back pain

Aneurysmal Bone Cyst of the Third Metatarsal Treated Using Free Nonvascular Fibular Strut Graft-A Rare Case Report

Introduction

An aneurysmal bone cyst (ABC) is an unusual, non-cancerous bone lesion that is characterized by its lytic (causing bone loss), hemorrhagic, and expanding nature. ABCs are relatively rare, making up only 1% of all bone tumors. These cysts are typically found in long bones and the spine but are very rarely seen in the metatarsal bones, making such occurrences quite uncommon.

Case Report

In this case report, we present a case of ABC of the 3rd metatarsal in a 26-year-old female with complaints of long-standing foot pain and gradually increasing swelling of the dorsum of the foot. After radiological evaluation, she had undergone histopathological evaluation. An en bloc resection of the metatarsal along with the tumor mass was performed and the gap was replaced with an ipsilateral fibular strut graft. Histopathological examination of the resected tissue was suggestive of ABC without any evidence of malignancy. At the end of 1 year of follow-up, she is now completely pain free with intact rom of foot and ankle.

Conclusion

The present study aims to describe a case of ABC of the metatarsal, a condition that not only poses a diagnostic dilemma but also constitutes a challenge in the management of lesion.

Tumors and pseudotumors of foot and ankle: Bone lesions

Bone tumors and tumor-like lesions (pseudotumors) are not uncommonly encountered as asymptomatic findings on imaging, or as symptomatic lesions clinically. Radiographic imaging is the first diagnostic tool for their management strategy, since the symptoms are commonly non-specific, such as pain, swelling, and redness. Image findings must be analyzed with attention to the specific features such as lesion location, margination, zone of transition, mineralization, size and multifocality, soft tissue component and/or loco-regional extent. Cross-sectional imaging including CT and MRI serve as complementary methods, providing additional information with respect to the lesion characterization, mineralization, extent and involvement of the adjoining soft tissues. Clinical and/or key imaging features aid in limiting the differential diagnostic possibilities and serve as a guide in determining the benignity or malignancy of the tumor as well as to exclude pseudotumors. This article reviews the key imaging features of foot and ankle lesions. Benign bone lesions include simple and aneurysmal bone cysts, lipoma, hemangioma, chondroblastoma, enchondroma, osteoid osteoma, osteoblastoma, and giant cell tumor. Locally aggressive intermediate category lesion includes hemangioendothelioma. Malignant lesions include osteosarcoma, Ewing's sarcoma, chondrosarcoma. Pseudotumors such as fibrous dysplasia, hemophilic pseudotumor, gout and Madura foot are also discussed with illustrative case examples.

Aneurysmal bone cyst in thoracolumbar spine

Aneurysmal bone cysts (ABC) are rare, benign primary bone tumors. Although benign, they can be locally aggressive resulting in erosion of bone and surrounding tissues over time. In later stages, depending on the clinical urgency, immunotherapy or surgical resection remain treatment options. This report illustrates a case of a 32-year-old female who presented with chronic worsening low back pain without neurological deficits. Radiological imaging revealed a large destructive mass arising from the thoracic spine invading into the central canal, causing critical central stenosis and cord compression. Histopathology revealed ABC. This case highlights the importance of including ABCs and other ‘benign’/locally aggressive lesions in the differential of patients with insidious musculoskeletal complaints. This case also demonstrates that one can be neurologically asymptomatic despite having critical central canal stenosis and cord compression if the causative lesion is slow growing. Understanding this allows us to arrange for most appropriate management.

Aneurysmal bone cyst of the metatarsal: A case report

An aneurysmal bone cyst (ABC) is a rare, non-neoplastic, destructive, hemorrhagic and expansile lesion accounting for 1% of all bone tumors. This type of lesion predominantly affects long bones and vertebrae. ABC of the metatarsal is rare and only a few cases have been reported in the literature to date. The present study reports a rare case of ABC of the third metatarsal occurring in a 27-year-old male patient, who presented with repeated foot swelling that had lasted for ~1 year. Other clinical manifestations included limping, multiple lumps (defined as masses on or below the skin, as detected by imageological diagnosis) and progressively increasing local pain in his right foot. Magnetic resonance imaging of the right metatarsal revealed a segmented, expansile, multiseptated lesion with fluid-fluid levels. An en bloc resection was performed and the defect was replaced with a tricortical iliac autograft. Pathological analysis of the resected tissue suggested ABC. The present study aims to describe a case of ABC of the metatarsal, a condition that often poses a diagnostic challenge, and to underline the importance of radiological and histological examinations for the accuracy of that diagnosis.