Multiloculated solitary (unicameral) bone cyst in a young dog

A 20-month-old female spayed Staffordshire Terrier (22.3 kg) presented to the Orthopedic Surgery Service at North Carolina State University Veterinary Teaching Hospital for evaluation of a 6-week history of toe-touching to nonweight-bearing lameness in the right hind limb. Radiographs of the right stifle revealed a multiloculated lytic lesion of the distal femur, with a large open lytic zone centrally, numerous osseous septations peripherally, and focal areas of cortical thinning and loss. An aspirate of the right distal femoral lesion yielded mildly cloudy serosanguineous fluid. Cytologic examination of the fluid revealed a pleomorphic population of discrete cells that exhibited marked anisocytosis and anisokaryosis and a variable nuclear-to-cytoplasmic (N:C) ratio, which were interpreted as probable neoplastic cells, with few macrophages, and evidence of hemorrhage. Given the clinical signs of pain, lesion size, and concern for malignant neoplasia, amputation of the right hind limb was performed. Histologically, the lesion had undulating walls 1-3 mm thick with a continuous outer layer of dense fibrous tissue and an inner layer composed of reactive cancellous bone with no cortical compacta remaining. Remnants of thin fibrous or fibro-osseous septa projected from the bony wall into the cyst lumen. The final histologic diagnosis was a benign multiloculated solitary (unicameral) bone cyst of the distal right femur. Based on the histopathologic findings, it was speculated that the cells identified on cytology were a mixture of developing osteoclasts, osteoblasts, endothelial, and stromal cells. This is the first report describing the cytologic examination of a solitary bone cyst in veterinary medicine.

Maxillofacial fibro-osseous lesions

During the last decade much has changed in our understanding of fibro-osseous lesions (FOLs) of the jaws with regards to their imaging, their nomenclature and classification, and their potential impact on the overall health of the patient. The changes in nomenclature, classification, and the FOLs' potential association with important syndromes are discussed with the assistance of a flowchart. The lesions, fibrous dysplasia (FD), ossifying fibroma (OF), and osseous dysplasia (OD), though with similar histopathology, have very different clinical and radiological presentations, behaviour, and treatment outcomes. FD of the jaw, which though becoming inactive, does not involute and therefore requires life-long review to monitor for occasional reactivation. OF is completely removed surgically as it has a propensity to recur. No treatment is generally required for an OD unless it is infected or displays expansion. Lesions outside the jaws associated with FOLs of the jaws are identified. Radiology remains central to the diagnosis of FOLs of the jaw, because the pathologist is still not able to distinguish between them. The advent of cone-beam computed tomography (CBCT) with its better radiation dose reduction, accessibility, and spatial resolution has transformed imaging of FOLs. Their presentations on CBCT and the clinical indications for its use are discussed.

Juvenile ossifying fibroma diagnosed on fine needle aspiration cytology: a diagnostic challenge

Preoperative diagnosis of jaw lesions is not always possible on the basis of clinico-radiological findings alone and needs to be confirmed before attempting any surgical intervention. Fibro-osseous lesions of the jaw comprise a spectrum of diseases which include cement-osseous dysplasia, fibrous dysplasia, and ossifying fibroma. The cytomorphological distinction between these individual entities is difficult. We present a case of maxillary fibro-osseous lesion in an adolescent girl diagnosed and categorized as juvenile ossifying fibroma preoperatively on cytology and confirmed on histopathology. Although aspirates are usually paucicellular in fibro-osseous lesions, certain cytological features if present in cellular cytosmears can offer further categorization and a definitive diagnosis may be possible in light of clinico-radiological correlation.

The role of cytology in the diagnosis of musculoskeletal neoplasms: systematic review

The authors systematically reviewed the literature of the last decade on the role of cytology in the evaluation of musculoskeletal neoplasms, and its diagnostic accuracy. A search was carried out on the databases PubMed, MEDLINE, LILACS and SciELO, selecting articles in which cytology was used in the diagnosis of musculoskeletal neoplasms. Limits were used for English, Spanish and Portuguese, and only articles published since 2000 were selected. 757 articles were retrieved, 24 of which were selected based on criteria of inclusion and exclusion. It was concluded that although promising in the assessment of musculoskeletal neoplasms, cytology obtained by fine needle aspiration is less accurate and reliable than histological evaluation of such lesions.

Bone Cytology: A Realistic Approach for Clinical Use

This article presents the use of bone cytology for diagnosis of bone tumors. It discusses critical factors and considerations of fine-needle aspiration and bone cytology and presents diagnostic options and differential diagnosis for benign and malignant bone lesions. Osteomyelitis, chrondroblastoma, Langerhans cell histiocytosis, chondromyxoid fibromas, enchondromas, giant cell tumor of bone, osteosarcoma, chondrosarcoma and variants, Ewing sarcoma, chordoma, plasmacytoma, multiple myeloma, lymphoma, and metastatic bone disease are presented.

Fine needle aspiration cytology in a case of fibrous dysplasia of jaw

Fibro-osseous lesions of the jaw comprise of a spectrum of diseases which include osseous dysplasia, fibrous dysplasia, and ossifying fibroma. The differentiation amongst these individual pathological lesions is difficult and a combined clinico-radiological and histological correlation is essential for exact categorization. Fine needle aspiration cytology (FNAC) is frequently carried out to distinguish between benign and malignant lesions of the jaw as is a quick and reliable modality of investigation which guides in further management. We report, a case of a jaw swelling in a young male, diagnosed as fibrous dysplasia on FNAC.