Myositis Ossificans of the Breast Mimicking Breast Cancer: A Case Report.

Myositis ossificans (MO) is an uncommon tumor characterized by a rapidly growing mass following a history of local trauma. Few cases of MO affecting the breast have been reported, and some were misdiagnosed as primary osteosarcoma of the breast or metaplastic breast carcinoma. The following case report presents a patient with a growing breast lump whose core biopsy result was suspicious for breast cancer. MO was diagnosed after analysis of the mastectomy specimen. This case highlights the importance of MO as a differential diagnosis of a growing soft-tissue mass after trauma to avoid unnecessary overtreatment. Keywords: Myositis Ossificans, Osteosarcoma, Breast Cancer, Mastectomy, Heterotopic Ossification © RSNA, 2023.

The impact of rapid on-site evaluation on thyroid fine-needle aspiration biopsy: A 2-year cancer center institutional experience.

BACKGROUND: The impact of rapid on-site evaluation (ROSE) on thyroid aspirates has been a matter of extensive debate. In the current study, the authors reviewed all thyroid fine-needle aspiration biopsies (FNABs) performed in their service in recent years to evaluate the impact of ROSE on final adequacy and diagnostic rates. METHODS: All ultrasound-guided FNABs of the thyroid performed between July 2015 and July 2017 were included retrospectively. ROSE was performed by experienced cytopathologists, with production of Romanowsky-stained slides for immediate evaluation. When ROSE was not performed, a total of 3 needle passes were performed as the default. Final specimen adequacy and the risk of malignancy (ROM) of each The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) category were calculated in the 2 groups (ROSE and non-ROSE) and compared using the chi-square test. RESULTS: An initial search obtained 4649 cytology specimens, 3469 of which (74.6%) underwent ROSE and 1180 of which (25.4%) did not. Patients were predominantly female (85.4%), with a mean age of 53 years. Specimen adequacy was found to be significantly higher in the ROSE group (93.4% vs 69.4%; P<.0001), with a mean number of needle passes necessary for an adequate diagnosis of 1.48 ± 0.71 (median, 1.0 needle passes; range, 1-5 needle passes). No statistical difference was observed with regard to the ROM for each TBSRTC category when the 2 groups (ROSE and non-ROSE) were compared. CONCLUSIONS: The current study data support ROSE as a valuable technique in thyroid FNAB. It was proven to significantly improve specimen adequacy with a decreased mean number of needle passes necessary to achieve an adequate cytological diagnosis and no impact on the ROM for any TBSRTC category.

Retroperitoneal lipomatous tumors without cytologic atypia: are they lipomas? A clinicopathologic and molecular study of 19 cases.

Most well-differentiated liposarcomas can be readily distinguished from lipomas on histologic grounds alone. However, occasional retroperitoneal lipomatous tumors show no cytologic atypia. To determine whether these tumors are well-differentiated liposarcomas devoid of cytologic atypia or lipomas was the major aim of this investigation. We comprehensively and prospectively studied 19 retroperitoneal adipocytic tumors devoid of cytologic atypia at the cytogenetic and molecular genetic levels. Median patient age was 56 years (range: 36 to 78 y). Median tumor size was 21 cm (range: 8 to 46 cm) and the median weight was 1127 g (range: 173 to 2440 g). All tumors were well-circumscribed and showed no cytologic atypia. Standard cytogenetic analysis demonstrated rearrangements of 12q15 in 4 (of 7) cases. None showed ring or giant marker chromosomes. Fluorescence in situ hybridization failed to identify amplification of MDM2, carboxypeptidase M(CPM), SAS, CDK4, DDIT3, or HMGA2 in all cases. HMGA2 rearrangement was observed in 8 (of 19) cases (42%) and was more common in larger tumors (P=0.046). HMGA2-LPP fusion was seen in only 1 case. All tumors were completely excised. Follow-up information was available from 10 cases (median, 6 mo; range: 1 to 58 mo). No tumor recurred or metastasized. In contrast, a control group of 20 well-differentiated liposarcomas diagnosed during the same time period (matched per year of diagnosis) showed 4 instances of local recurrence. We conclude that this group of retroperitoneal lipomatous tumors shows clinico-pathologic and genetic features more akin to lipomas than well-differentiated liposarcomas. Owing to their apparent rarity, additional studies are necessary to more fully understand their natural biology in this anatomic location.

Primary retroperitoneal lipoma: a soft tissue pathology heresy?: report of a case with classic histologic, cytogenetics, and molecular genetic features.

Adipose tissue tumors of the retroperitoneum showing no identifiable cytologic atypia are usually classified as lipomalike well-differentiated liposarcoma. Whether a subset of these tumors represents true examples of retroperitoneal lipoma remains a controversial subject, because the diagnostic liposarcoma cells may be of difficult identification, even after extensive sampling. Herein, we describe a large retroperitoneal lipoma with classic histopathologic, cytogenetic, molecular cytogenetic, and molecular genetic features. Extensive morphologic inspection showed no evidence of cytologic atypia. Cytogenetic analysis performed on fresh tissue material revealed the classic lipoma chromosome t(3;12)(q27;q14-15). Fluorescence in situ hybridization on multiple sections excluded the presence of MDM2 and CDK4 amplification, but showed HMGA2 balanced rearrangement in most cells. Reverse-transcriptase polymerase chain reaction followed by sequencing analysis confirmed the presence of the HMGA2-LPP fusion gene, a characteristic and the most common fusion product found in lipoma. The patient has been followed for 2.5 years without evidence of recurrence or metastasis. These results indicate that retroperitoneal lipomata do exist, but their diagnosis must rely on stringent histologic, cytogenetic, and molecular genetic analysis.

Genomic gains of COL1A1-PDFGB occur in the histologic evolution of giant cell fibroblastoma into dermatofibrosarcoma protuberans.

Giant cell fibroblastoma (GCF) is a subcutaneous mesenchymal neoplasm characterized by the chromosomal t(17;22), which results in the formation of the fusion gene COL1A1-PDGFB. This same fusion gene is also seen in the supernumerary ring chromosome of dermatofibrosarcoma protuberans (DFSP). Several studies have addressed the molecular genetics of DFSP but molecular cytogenetic characterization of individual areas and cell components in pure GCF and GCF/DFSP hybrids have not been performed. Herein, we studied the frequency and genomic copy number of COL1A1-PDGFB in pure GCF and GCF/DFSP hybrids, and identified the molecular cytogenetic signatures in individual cells in each component. Four pure GCF and nine GCF/DFSP hybrids were studied. All tumors exhibited classical histological features and CD34 expression. COL1A1 and PDGFB rearrangements were evaluated by fluorescence in situ hybridization (FISH) using probes for COL1A1 and PDGFB on paraffin-embedded thin tissue sections. All GCF and GCF/DFSP hybrids showed unbalanced rearrangements of COL1A1-PDGFB at the molecular cytogenetic level. Genomic gains of COL1A1-PDGFB were found predominantly in the DFSP component of GCF/DFSP hybrids but in none of the pure GCF, suggesting that these gains are associated with the histologic evolution of GCF into DFSP. The molecular cytogenetic abnormalities were found not only in the spindle/stellated cells but also in individual nuclei of the multinucleated giant cells, suggesting that these cells may result from the fusion of individual neoplastic cells.

Myxoinflammatory fibroblastic sarcoma showing t(2;6)(q31;p21.3) as a sole cytogenetic abnormality.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare, low-grade sarcoma characterized by distinctive, large, and bizarre Reed--Sternberg--like cells associated with an intense inflammatory infiltrate. The biology of MIFS is still poorly understood, and only two previous cases had been studied cytogenetically. In the present case, analysis of MIFS in the foot of a 53-year-old man revealed the chromosome translocation t(2;6)(q31;p21.3) as the only cytogenetic abnormality. This finding is distinct from the two cases previously reported. Additional studies are needed to verify whether any of these chromosome rearrangements are involved recurrently in MIFS.

Paragangliomas da regiäo da cabeça e pescoço: estudo de 13 casos com correlaçäo clínico-patológica / Paragangliomas of the head and neck region: study of 13 cases with clinicopathologic correlations

Treze casos de paraganglioma em regiäo de cabeça e pescoço foram estudados e seus diferentes aspectos clínico-patológicos foram analisados. Ocorreu com maior freqüência na quarta década de vida, com discreta predominância no sexo feminino. A sintomatologia apresentada pelos pacientes variou com a localizaçäo da tumoraçäo. Näo houve casos de multicentricidade ou de incidência familiar. Neste estudo näo foram observadas características histológicas capazes de predizer o comportamento biológico desta neoplasia. No prognóstico, os fatores mais importantes parecem ser a redicalidade do tratamento cirúrgico inicial e a localizaçäo do processo neoplásico, com os tumores da regiäo júgulo-timpânica apresentando taxas de recidiva e mortalidade mais elevadas