Intraosseous lipomas originating from simple bone cysts

Malicious Tumor? Pathological Fracture of the Femur in Children Caused by Myelolipoma: A Case Report and Review of Literatures

Myelolipoma is a kind of benign lipoma containing myeloid cells. It is a rare type of tumor that typically presents as an occasional adrenal tumor, generally manifesting as a nonfunctional adrenal mass. Although it can occur in extra-adrenal tissues, its occurrence in bone tissue is extremely rare. Most cases are discovered accidentally during physical examinations of adults, and there are currently no reports of cases with pathological fractures as the main symptoms. We present a case of a 15-year-old teenager who developed a pathological fracture caused by femoral myelolipoma. The diagnosis of the specific type of bone tumor of the patient was determined through pathology and imaging. To treat the condition, we utilized a technique known as the "soft drill" to fully access the tumor space, remove the bone septum, and scrape away the diseased tissue. The fracture was then stabilized using a hybrid external fixation. After a 2-year follow-up period, there was no recurrence of the bone tumor. This case is the first case of intraosseous myelolipoma that occurred in a minor with the initial symptom of pathological fracture, filling the gap in our existing body of knowledge and providing a reference for the treatment of this type of intraosseous myelolipoma.

Insights into the Distribution Patterns of Foot and Ankle Tumours: Update on the Perspective of a University Tumour Institute

The rarity of foot and ankle tumours, together with the numerous histological entities, presents a challenge in accumulating sufficient patients to draw reliable conclusions. Therefore, we decided to present an update of a retrospective analysis of their distribution patterns, comprising 536 cases of foot and ankle tumours presented to our tumour board between June 1997 and June 2023. Our aim was to provide a comprehensive overview of the prevalence and distribution patterns of benign and malignant bone and soft tissue tumours of the foot and ankle. A total of 277 tumours involved bone (51.7%). Of these, 242 (87.4%) were benign and 35 (12.6%) were malignant. In addition, 259 soft tissue tumours (48.3%) were found, of which 191 (73.7%) were benign and 68 (26.3%) were malignant. The most common benign bone tumours were simple bone cysts, enchondromas, osteochondromas, aneurysmal bone cysts, and lipomas of bone. Common benign soft tissue tumours included a tenosynovial giant cell tumour, haemangioma, plantar fibromatosis, schwannoma, and lipoma. The most common malignant soft tissue tumours were synovial sarcoma, malignant melanoma, and myxofibrosarcoma. In terms of anatomical location, the hindfoot was the most common site (28.7%), followed by the midfoot (25.9%), ankle (25.4%), and forefoot (20.0%). The distribution of benign entities often follows typical patterns, which may facilitate an early diagnosis even without biopsy (e.g., simple bone cyst, plantar fibromatosis). On the other hand, the distribution patterns of many rare or malignant entities are inconsistent. Individual soft tissue malignancies occur very sporadically, even over long periods of time and in specialized tumour centres. It is therefore important to recognise that any suspicious mass in the foot and ankle must be considered a possible malignancy until proven otherwise.

Idiopathic bone cavity mimicking a botryoid odontogenic cyst: A rare radiographic presentation in an older adult

OBJECTIVES

This report describes an unusual case of a multilocular idiopathic bone cavity (IBC) that presented as a botryoid odontogenic cyst situated between the mandibular lateral incisor and canine in an older adult.

BACKGROUND

The IBC represents an intraosseous concavity that appears radiographically as a unilocular or multilocular radiolucent lesion found in various skeletal sites, including the jaw. Atypical cases of gnathic IBC have not been appreciated in the gerodontologic literature.

MATERIALS AND METHODS

The teeth adjacent to the bony lesion had normal pulpal responses to cold. A full-thickness flap was elevated and provided a direct entry into a bony concavity, which was devoid of an epithelial lining and fluid.

RESULTS

The lack of a cystic lining within the empty osseous lesion following surgical entry, concomitant with the vital pulpal status of the proximal teeth, led to a diagnosis of an IBC. The bony walls underwent curettage and copious irrigation prior to primary closure. A 10-month follow-up revealed partial evidence of osseous repair. The patient will continue to be monitored.

CONCLUSION

Timely surgical intervention of central lesions of the jaws may improve clinical outcomes. Variants of the IBC should be included in the differential diagnosis of multilocular lesions, particularly in the geriatric population.

Allogenic Cancellous Bone versus Injectable Bone Substitute for Endoscopic Treatment of Simple Bone Cyst and Intraosseous Lipoma of the Calcaneus and Is Intraosseous Lipoma a Developmental Stage of a Simple Bone Cyst?

Simple bone cysts (SBCs) and intraosseous lipoma (IOL) of the calcaneus are rare tumor entities that are primarily diagnosed due to unspecific heel pain, incidental findings, or rarely due to pathological fractures. Compared to traditional open tumor resections, endoscopic resection of these benign tumors aims to minimize surgical morbidity and maximize surgical efficiency without compromising safety. Grafting is regularly performed to reduce the risk of recurrence and stimulate osseous consolidation of the lytic lesion. As the incidence is low and treatment strategies are heterogeneous, there is no clear consensus for the treatment of simple cysts or intraosseous lipomas of the calcaneus. The objectives of this study are (a) to present medium to long-term results after endoscopic resection and grafting with allogenic cancellous bone or bioresorbable hydroxyapatite and calcium sulfate cement, and (b) to add further evidence to the discussion of whether calcaneal SBC and IOL are the same entity at different developmental stages. Between 2012 and 2019, a total of 25 benign bone tumors consisting of 17 SBCs and 8 IOLs were treated by A.T. with endoscopic resection and grafting, comprising the largest cohort to date. For grafting, 12 patients received allogenic cancellous bone (group A) and 13 patients received injectable bone substitute (group B). Pre- and postoperative imaging using plain X-rays and MRI was retrospectively analyzed with a mean follow-up time of 24.5 months to assess tumor size, osseous consolidation (modified Neer classification), and tumor recurrence. A retrospective chart analysis focusing on adverse intra- and perioperative events and other complications associated with the surgical procedure was performed using the modified Clavien-Dindo classification (CD1-3). A total of 12/13 cases with allogenic bone grafting showed a Neer Type 1 osseous healing of the tumorous lesion after endoscopic resection, whereas only 5/11 cases with injectable bone substitute showed sufficient healing (types 1 and 2). There were three recurrent cysts (Neer 4) and two persistent cysts (Neer 3) after using injectable bone substitute. Two CD1 complications were observed in group A (prolonged wound drainage, sural neuritis) and eight complications were observed in group B (6× CD1, 2× CD3). At least two IOLs diagnosed preoperatively using MRI were ultimately identified as SBCs upon histopathologic examination. Allogenic cancellous bone grafting after endoscopic resection of calcaneal SBC or IOL showed a very low rate of complications and no tumor recurrence in our series. On the other hand, depending on the material used, injectable bone substitute showed a high rate of "white-out" (excessive drainage), resulting in multiple complications such as prolonged wound healing, insufficient permanent defect filling, recurrence, and revision surgery. Over time, calcaneal SBC may transform into IOL, exhibiting distinct features of both entities simultaneously during ossoscopy and histopathological analysis.

Society of Skeletal Radiology- white paper. Guidelines for the diagnostic management of incidental solitary bone lesions on CT and MRI in adults: bone reporting and data system (Bone-RADS)

The purpose of this article is to present algorithms for the diagnostic management of solitary bone lesions incidentally encountered on computed tomography (CT) and magnetic resonance (MRI) in adults. Based on review of the current literature and expert opinion, the Practice Guidelines and Technical Standards Committee of the Society of Skeletal Radiology (SSR) proposes a bone reporting and data system (Bone-RADS) for incidentally encountered solitary bone lesions on CT and MRI with four possible diagnostic management recommendations (Bone-RADS1, leave alone; Bone-RADS2, perform different imaging modality; Bone-RADS3, perform follow-up imaging; Bone-RADS4, biopsy and/or oncologic referral). Two algorithms for CT based on lesion density (lucent or sclerotic/mixed) and two for MRI allow the user to arrive at a specific Bone-RADS management recommendation. Representative cases are provided to illustrate the usability of the algorithms.