Intrapatellar tendon lipoma with chondro-osseous differentiation: detection of HMGA2-LPP fusion gene transcript

Is the treatment for osteochondrolipomas and lipomas the same? Case report and review of the literature on osteochondrolipoma of chest wall

Lipomas containing bony and chondroid areas are called osteochondrolipomas. Osteochondrolipomas are extremely rare and their treatment is not known exactly. In this article, we report a 41-year-old male patient who had a 45 mm long subcutaneous mass in the chest wall which was detected 15 years before. When the mass started to grow recently, the patient was admitted to our hospital. Total excision was performed to the mass of the chest wall. According to the histopathological examination of the material, the lesion was an osteochondrolipoma. It might be challenging to diagnose such rare osteochondrolipomas in the tru-cut or small biopsy specimens. Differential diagnosis may be challenging clinically, radiologically, and histopathologically. To our knowledge, this is the fifth case of a totally excised osteochondrolipoma of the chest wall which was reported in the literature.

Infiltrating hybrid mesenchymal tumor of skeletal muscle showing lipomatous, hemangiomatous, leiomyomatous and osseous features - An unusual soft tissue tumor providing insight into the pathogenesis of lipoma variants

Infiltrating angiolipoma and osteolipoma of the hand are rare. A 40-year-old man presented with slowly enlarging swelling of his right hand for two and half years without functional deficit but it became painful with slight limitation of movement for the past few months. Plain radiograph showed a large soft tissue swelling with specks of calcifications. Ultrasonography and magnetic resonance imaging revealed an infiltrative mass in the right palm deep to the flexor tendons. As biopsy suggested infiltrative angiolipoma of skeletal muscle, debulking of the tumor was performed. The tumor showed coexistence of all four mesenchymal elements, fat, blood vessel, smooth muscle and bone in various combinations in the form of angiolipomatous, osteolipomatous, ossified intramuscular hemangiomatous, myolipomatous and angiomyolipomatous patterns throughout the entire tumor. Small meningothelial-like whorls of spindle cells were focally seen, some showed intramembranous ossification forming small woven bony spicules in their centers. There were no atypical cells or lipoblasts. Staining for CDK4, MDM2, p16, HMB45 and Melan A was negative. The diagnosis was "infiltrating hybrid mesenchymal tumor of skeletal muscle showing lipomatous, hemangiomatous, leiomyomatous and osseous features". The fairly even admixture of the various components supports the neoplastic participation of each individual element. Hybrid mesenchymal tumor most probably originates from multipotent neoplastic cells showing multidirectional differentiation.

Endoscopic resection of lipoma of the patellar tendon

Synovial lipoma of the patellar tendon is a very rare entity. It can be associated with rupture of the patellar tendon. We present a case of synovial lipoma that was successfully resected endoscopically. The other indications for patellar tendoscopy include chronic patellar tendinitis and tendinosis, recalcitrant bursitis around the tendon, Osgood-Schlatter disease, and jumper's knee. The major potential danger of this endoscopic procedure is iatrogenic damage to the patellar insertion during endoscopic debridement in patients with jumper's knee or the tibial insertion during endoscopic debridement in patients with Osgood-Schlatter disease.

Osteochondrolipoma of the submandibular region: a case report and review of the literature

Lipoma is an extremely common and ubiquitous benign soft tissue tumor composed of mature adipose tissue, with frequent differentiation towards other mesenchymal elements such as blood vessels, fibrous tissue, or muscle. They are typically slow-growing, encapsulated, superficial or deep, and have a wide range in size depending on their location. The presence of cartilage or bone is very rare, with most reported cases in the head and neck area. We report the case of an osteochondrolipoma of the submandibular region with associated benign bone marrow elements, with a review of the literature and discussion of the differential diagnosis.

Osteolipoma: radiological, pathological, and cytogenetic analysis of three cases

Osteolipoma is a rare variant of lipoma consisting of mature adipose tissue and mature lamellar bone. The presence of non-fatty elements may lead to a wide differential diagnosis on radiology including benign and malignant lipomatous and nonlipomatous entities. The pathological diagnosis is also confounded by the presence of heterologous differentiation. Fortunately, most lipomas harbor classic cytogenetic aberrations, and the finding of translocations involving 12q13-15 may aid in the correct diagnosis. We report three cases of osteolipoma with radiological, histological, and cytogenetic correlation.

Gene delivery of TGF-β1 induces arthrofibrosis and chondrometaplasia of synovium in vivo

To understand the cellular and molecular events contributing to arthrofibrosis, we used an adenovirus to deliver and overexpress transforming growth factor-beta 1 (TGF-β1) cDNA (Ad.TGF-β1) in the knee joints of immunocompromised rats. Following delivery, animals were killed periodically, and joint tissues were examined macroscopically and histologically. PCR-array was used to assay alterations in expression patterns of extracellular matrix (ECM)-associated genes. By days 5 and 10, TGF-β1 induced an increase in knee diameter and complete encasement of joints in dense scar-like tissue, locking joints at 90° of flexion. Histologically, massive proliferation of synovial fibroblasts was seen, followed by their differentiation into myofibroblasts. The fibrotic tissue displaced the normal architecture of the joint capsule and fused with articular cartilage. RNA expression profiles showed high levels of transcription of numerous MMPs, matricellular and ECM proteins. By day 30, the phenotype of the fibrotic tissue had undergone chondrometaplasia, indicated by cellular morphology, matrix composition and >100-fold increases in expression of collagen type II and cartilage link protein. Pre-labeling of articular cells by injection with recombinant lentivirus containing eGFP cDNA showed fibrotic/cartilaginous tissues appeared to arise almost entirely from local proliferation and differentiation of resident fibroblasts. Altogether, these results indicate that TGF-β1 is a potent inducer of arthrofibrosis, and illustrate the proliferative potential and plasticity of articular fibroblasts. They suggest the mechanisms causing arthrofibrosis share many aspects with tumorigenesis.

Giant lipoma of the thenar--case study and contemporary approach to its aetiopathogenicity

Giant lipomas of the thenar are rare tumours of the adipose tissue of the hand, with a benign prognosis. Apart from the cosmetic problems they may cause, their most frequent complications include a compromise in functionality and pressure upon the nerves, mainly on the radial nerve. The first step in their management is their differential diagnosis from well-differentiated liposarcomas (WDLPS), as they require a different therapeutic approach. This step is completed with the aid of MRIs, biopsies and modern immunohistochemical methods, which offer high specificity and sensitivity. Our paper presents a case of giant lipoma of the thenar, with a review of the relevant literature, focusing on the disease's molecular genetics, which is a very important field of research today.

Aggressive angiomyxoma with t(12;21) and HMGA2 rearrangement: report of a case and review of the literature

Conventional cytogenetic analysis of an aggressive angiomyxoma of the rectal wall of a 72-year-old woman revealed a translocation between the long arms of chromosomes 12 and 21, with the karyotype 46,XX,t(12;21)(q15;q21.1). Involvement of the HMGA2 gene locus (12q15) was confirmed by fluorescence in situ hybridization using an HMGA2 breakpoint flanking probe set performed on metaphase and interphase cells from an in situ culture of fresh lesional tissue. Karyotypic rearrangements of 12q13 approximately q15 are considered recurrent in aggressive angiomyxoma, although reported in only five previous cases. Translocation partner chromosome 21 is unique to the present case.