Supernumerary ring chromosomes derived from the long arm of chromosome 12 as the primary cytogenetic anomaly in a rare soft tissue chondroma

Extraskeletal Intramuscular Chondroma of the Knee - Case Report and Review of the Literature

Extraskeletal chondromas are small nodular cartilaginous lesions not attached to bone or the periosteum. They are rare tumors commonly occurring in the hands and feet. The objective of the present study is to describe a case of extraskeletal intramuscular chondroma (EIC) in the left knee and the diagnostic challenges faced by us. A 25-year-old female patient presented with slow-growing swelling in the left knee for 2 years. Clinically, the swelling was arising from the quadriceps muscle. We considered possibilities such as rhabdomyoma, neurofibroma, and intramuscular lipoma. Imaging studies suggested a benign fatty tumor. She was treated by excision. Microscopy was consistent with EIC without recurrence. A rare entity, clinically, EIC can mimic other benign soft-tissue tumors. Histopathology exams can provide a definitive diagnosis. The excision of the tumor is curative.

Soft tissue chondroma of the oral cavity: an extremely rare tumour localized on the hard palate

Chondromas are benign cartilaginous tumors usually localized within the tubular bones of the extremities. Soft tissue chondromas (STCs) are rare and only few cases have been reported in the oral cavity. The present case documents the exceptional finding of a 12-year-standing STC of the hard palate of a 63-year-old man. The tumor measured approximately 6 cm in its larger size and it was radically excised through the use of a quantic resonance molecular (QRM) lancet. No recurrence was observed during 1-year follow-up. A concise review of the relevant literature is included in the present paper.

Cartilaginous choristoma of the tongue with an immunohistochemical study

By definition, choristomas are normal tissues found in anomalous topography. The cartilaginous features of these lesions are rare in the soft tissues of the oral cavity. The majority of cartilaginous choristomas of the tongue--the primary site of emergence of the oropharynx--are associated with adipose, fibrous or bone tissues--apart from that, only a few of these were confirmed by an immunohistochemical study. The neoplasm exclusively composed of chondromatous tissue is extremely rare in the tongue. This paper reports the clinical, surgical and pathological characteristics of a cartilaginous choristoma of the tongue diagnosed in a 64-year-old woman.

Cytogenetic findings in 14 benign cartilaginous neoplasms

Benign cartilaginous tumors represent a spectrum of neoplastic processes with variable clinical and pathologic presentations. These tumors are histologically characterized by the presence of chondrocytes surrounded by a cartilaginous matrix. Few studies describe karyotypic abnormalities in these benign lesions. We report a series of 14 chondromas from a single institution. Conventional cytogenetics was performed on short term cultures from all cases. Clonal chromosome aberrations were found in nine tumors. One soft tissue chondroma contained three clones with t(6;12)(q12;p11.2), t(3;7)(q13;p12), and der(2)t(2;18)(p11.2;q11.2). Three periosteal chondromas displayed random structural aberrations of chromosomes 2, 3, 6, 7, and 11 and loss of chromosome 13. Among the enchondromas, three tumors displayed chromosome losses, one contained a complex translocation involving chromosomes 12, 15, and 21 as well as an inv(2)(p21q31),t(12;15;21)(q13;q14;q22) and a separate enchondroma showed a translocation involving chromosomes 12 and 22. Our data suggest that considerable cytogenetic heterogeneity exists among benign chondromatous tumors.

Molecular pathology of chondroid neoplasms: part 1, benign lesions

This two-part review presents an overview of the molecular findings associated with both benign and malignant chondroid neoplasms. This first part presents a brief review of methods in molecular pathology along with a review of the cytogenetic and molecular genetic findings in benign chondroid neoplasms. Clinical aspects of the various lesions are briefly discussed, and each tumor is illustrated with representative radiographic and pathologic images. Malignant chondroid neoplasms will be considered in the second part of this review.

Massive cardiac chondroma presenting with heart failure and superior vena cava obstruction in a teenage boy

Histologically benign soft-tissue chondromas have been reported at many anatomical sites but are an uncommon cause of soft tissue mass lesions in childhood, accounting for less than 1% of cases. The most frequent sites for extraosseous soft-tissue chondromas are the hands and feet. For the extremely rare visceral chondromas, the site can be lung, where they may represent a component of Carney's syndrome of extra-adrenal paraganglioma, pulmonary chondroma, and epithelioid leiomyosarcoma of the gastrointestinal tract. Primary cardiac chondromas are exceptionally rare in patients of any age although cardiac chondrosarcoma, both primary and metastatic, is well reported. We present a case of a teenage boy with a fatal cardiac chondroma

Cytogenetic findings in benign cartilaginous neoplasms

Cytogenetic analysis has improved our understanding of the histopathogenesis of many benign and malignant bone and soft tissue tumors, as well as served as an important diagnostic adjunct for these pathologic entities. Cytogenetic reports of benign cartilaginous tumors, however, are relatively few. This is unfortunate, as distinguishing benign and malignant cartilaginous neoplasms can often be difficult. In this study, the cytogenetic findings of two enchondromas, two periosteal chondromas, and one soft part chondroma and a review of the literature are reported. Abnormal diploid or near-diploid clones were detected in all specimens analyzed. Although a tumor-specific anomaly did not emerge from these studies, involvement of certain chromosomes/chromosomal regions appears recurrent.

Genetic and molecular abnormalities in tumors of the bone and soft tissues

BACKGROUND

Malignant transformation requires the accumulation of multiple genetic alterations such as chromosomal abnormalities, oncogene activation, loss of tumor suppressor genes, or abnormalities in genes that control DNA repair and genomic instability. Sarcomas are a heterogeneous group of malignant mesenchymal tumors of difficult histologic classification and strong genetic predisposition. This article provides a comprehensive review of the cytogenetic abnormalities observed in bone and soft-tissue tumors, emphasizing known downstream molecular changes that may play a role in oncogenesis.

METHODS

The database of the National Library of Medicine was searched for literature relating to genetic and molecular mechanisms in sarcomas in general and in each of the main tumor entities.

RESULTS

Recent techniques in chromosome analysis and molecular cytogenetics have improved our ability to characterize genetic changes in mesenchymal tumors. Some changes are so characteristic as to be virtually pathognomonic of particular histologic types, while others are complex, difficult to characterize, and of unknown relevance to pathogenesis. The implications to the cell of some of these abnormalities are now being recognized.

CONCLUSIONS

The study of sarcomas will benefit from the information derived from genetic studies and translational research. The human genome project and new methodologies, such as computer-based DNA microarray, may help in the histogenetic classification of sarcomas and in the identification of molecular targets for therapy.

Chondroblastoma-like chondroma of soft tissue: an underrecognized variant and its differential diagnosis

Soft-tissue chondromas are usually composed entirely of mature hyaline cartilage. Infrequently, however, they may exhibit morphologic features that result in diagnostic difficulty. The authors report a series of eight hypercellular soft-tissue chondromas composed of enlarged chondrocytes within a variable amount of chondroid matrix that often demonstrated delicate calcifications and contained numerous osteoclast-like multinucleated giant cells. This histologic appearance closely resembles that of chondroblastoma of bone. However, its extraosseous location, dense cellularity, and poorly formed cartilage can cause confusion with more aggressive chondroid neoplasms of soft tissue. The clinicopathologic features of these chondroblastoma-like chondromas are discussed, emphasizing the characteristics that facilitate their accurate identification.