CASE REPORT |
https://doi.org/10.5005/jojs-10079-1166 |
A Rare Case of Aneurysmal Bone Cyst of Calcaneum: A Case Report
1–6Department of Orthopedics, Government General Hospital, Anantapur, Andhra Pradesh, India
Corresponding Author: Raghavendra Raju RP, Department of Orthopedics, Government General Hospital, Anantapur, Andhra Pradesh, India, Phone: +91 7680089971, e-mail: raju.svmc@gmail.com
Received: 22 March 2024; Accepted: 14 April 2024; Published on: 14 Jane 2024
ABSTRACT
Aneurysmal bone cysts (ABC) are common benign expansile lytic lesions of bone usually presenting in the 2nd decade of life. They are locally aggressive lesions. The most common site of lesion is metaphyseal lesions of long bones like the femur, tibia, and radius. However, they can occur in flat bones like the spine and pelvis. The most common symptom is pain and swelling of the affected site. Here, we are presenting a rare case of ABC of calcaneum who has presented to us with pain and swelling of the heel for 3 months. There was no significant history of trauma. Clinical examination showed swelling and tenderness of the calcaneum. Radiographs were taken which showed lytic lesions of calcaneum with multiple cysts. A magnetic resonance imaging (MRI) scan was done which showed a lytic lesion with multiple fluid levels in the lesion. The patient was taken for an open biopsy and fibula and iliac bone grafting. Bone biopsy confirmed the diagnosis of ABC, and the patient was pain-free after 2 months of surgery. This case report gives insight into the diagnosis of ABC at unusual sites and treatment protocol.
How to cite this article: Pal CK, RP RR, Meda A, et al. A Rare Case of Aneurysmal Bone Cyst of Calcaneum: A Case Report. J Orth Joint Surg 2024;6(2):190–192.
Source of support: Nil
Conflict of interest: None
Patient consent statement: The author(s) have obtained written informed consent from the patient for publication of the case report details and related images.
Keywords: Aneurysmal bone cyst, Benign bone tumor, Biopsy, Bone grafting, Calcaneum, Case report
INTRODUCTION
Aneurysmal bone cysts (ABC) manifest as cystic, locally aggressive, and expansible bone lesions. They are typically benign and commonly found in the pediatric age-group, representing 1–6% of all primary benign bone tumors.1 There is a slight preponderance in the female population, with an estimated male and female sex ratio of 1:1.16.2 The long bone metaphysis is primarily (67%) affected by ABCs. They are also seen arising in the spine (15%) and pelvis (9%).3 Most patients present with an insidious onset of pain and swelling of the affected part.
The term “aneurysmal bone cyst” is inaccurate, as these growths do not exhibit characteristics of an aneurysm nor do they possess a true cystic structure due to the absence of an endothelial wall. Instead, these nonmalignant, expansive lesions generate hollow spaces within the bone, which become filled with blood and are surrounded by proliferative fibroblasts, giant cells, and trabecular bone (Fig. 1).4,5 Microscopically, they are multiloculated cystic lesions with multiloculated giant cells filled with blood and hemorrhage. Basophilic calcified material, known as “blue reticulated chondroid-like material,” may be detected within the walls of the cyst.6
Fig. 1: Preoperative X-ray
Radiograph shows cystic lesions exhibit slender “eggshell” sclerotic borders. Within the enclosed cavity, numerous dividing septa are present.7 Evaluation of these lesions is done by computed tomography (CT) (Fig. 2) and magnetic resonance imaging (MRI). An open biopsy is a must to confirm the provisional diagnosis.
Fig. 2: Computed tomography scan
CASE DESCRIPTION
A 19-year-old male patient arrived at our outpatient department complaining of heel discomfort that had persisted for 3 months. A history of trauma or other significant history is not presented. The pain was insidious in onset and progressed to the present stage. On examination, heel swelling and tenderness were found. Ankle and subtalar movements were normal.
A radiograph (Fig. 1) showed a lytic lesion in the calcaneum with multiple cysts (Fig. 3). An MRI (Fig. 4) scan revealed multiple cysts filled with fluid. An initial preoperative workup was done, after which the patient underwent an open biopsy, curettage, and bone grafting procedure. Through the lateral approach, curettage was performed, and the cavity of the lesion was filled with fibula and bone grafts harvested from the ilium (Fig. 5). A histopathological examination (HPE) (Fig. 6) was done on the curetted bone.
Fig. 3: Computed tomography scan
Fig. 4: Magnetic resonance imaging
Fig. 5: Immediate postoperative X-ray after curettage and bone grafting
Fig. 6: Six-month postoperative X-ray
A 6-month follow-up was done on the patient both clinically and radiologically (Fig. 7). He was advised not to bear on the affected limb for 6 weeks. He was allowed to walk without support after 3 months. The patient had no pain after 3 months, and a bony union was seen after 3 months. There was no wound healing or other complications.
Fig. 7: Histopathological examination slide
DISCUSSION
Aneurysmal bone cysts represent uncommon, fluid-filled cystic lesions characterized by local tissue destruction, yet they are typically benign in nature. They affect the long bone metaphysis, predominantly in the distal femur, proximal tibia, and vertebrae. The majority of ABCs occur in individuals under the age of 20. The lesion may originate either de novo (65%) or secondarily (35%) within preexisting benign or malignant conditions. It’s noteworthy that the calcaneus is an uncommon site for ABCs, accounting for only 1.6% of cases.8
The most common presentation typically involves the gradual onset of pain over a period of weeks or months. Some patients may also experience a sudden increase in pain due to pathological fractures.
On plain X-ray films, ABCs appear as eccentrically positioned radiolucent cystic lesions, confined by a thin cortical bone. Septations within the lesion can create a “soap bubble appearance.” However, these multiple fluid-filled lesions and soap bubble appearance are not pathognomonic to ABC.
Treatment options include curettage (Fig. 8) and bone grafting, en bloc resection, radiotherapy, radionuclide ablation, and cryosurgery arterial embolization.
Fig. 8: Curettage and bone grafting
The risk of tumor recurrence following surgical management varies, ranging between 12 and 75% of cases (recurrence is particularly high in children under the age of 5 years).
An accurate and prompt diagnosis of ABCs is crucial due to the wide range of potential differentials, encompassing both benign and malignant lesions, with telangiectatic osteosarcoma (TOS) being particularly noteworthy.9
CONCLUSION
Aneurysmal bone cysts are benign, aggressive lesions with high rates of recurrence. Early diagnosis and prompt treatment usually give a good prognosis. Curettage and bone grafting are nevertheless good options in ABC.
ORCID
Chayan K Pal https://orcid.org/0009-0006-9664-3802
Raghavendra Raju RP https://orcid.org/0000-0003-2944-7706
Athmaram Meda https://orcid.org/0009-0008-3647-4511
Chennur Shaik Mohammed Sibghatulla Mazhar https://orcid.org/0009-0003-4188-8712
Navya Pulimi https://orcid.org/0009-0003-6639-8701
Kiran Kumar Y https://orcid.org/0000-0001-6794-1540
REFERENCES
1. Boubou M, Atarraf K, Chater L, et al. Aneurysmal bone cyst primary—about eight pediatric cases: radiological aspects and review of the literature. Pan Afr Med J 2013;15:111. DOI: 10.11604/pamj.2013.15.111.2117
2. Leithner A, Windhager R, Lang S, et al. Aneurysmal bone cyst. A population based epidemiologic study and literature review. Clin Orthop Relat Res 1999;(363):176–179. DOI: 10.1097/00003086-199906000-00023
3. Mascard E, Gomez-Brouchet A, Lambot K. Bone cysts: unicameral and aneurysmal bone cyst. Orthop Traumatol Surg Res 2015;101(1 Suppl):S119–S127. DOI: 10.1016/j.otsr.2014.06.031
4. Fletcher CDM, Unni KK, Mertens F. Pathology and genetics of tumors of soft tissue and bone. World Health Organization Classification of Tumors. Lyon: IARC Press; 2002.
5. Copley L, Dormans JP. Benign pediatric bone tumors. Evaluation and treatment. Pediatr Clin North Am 1996;43(4):949–966. DOI: 10.1016/S0031-3955(05)70444-2
6. Bahk WJ, Mirra JM. Differential diagnostic value of “blue reticulated chondroid-like material” in aneurysmal bone cysts: a classic histopathologic analysis of 215 cases. Am J Clin Pathol 2015;143:823–829. DOI: 10.1309/AJCP33YDDJKFFTSV
7. Cottalorda J, Bourelle S. Modern concepts of primary aneurysmal bone cyst. Arch Orthop Trauma Surg 2007;127(2):105–114. DOI: 10.1007/s00402-006-0223-5
8. Babazadeh S, Broadhead ML, Schlicht SM, et al. Pathologic fracture of a calcaneal aneurysmal bone cyst. J Foot Ankle Surg 2011;50:727–732. DOI: 10.1053/j.jfas.2011.04.036
9. Park HY, Yang SK, Sheppard WL, et al. Current management of aneurysmal bone cysts. Curr Rev Musculoskelet Med 2016;9(4):435–444. DOI: 10.1007/s12178-016-9371-6
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