A spontaneously resolving breast lesion: imaging and cytological findings of nodular fasciitis of the breast with FISH showing USP6 gene rearrangement

Ossifying fasciitis of the proximal lower extremity

Ossifying fasciitis is a rare benign tumor of heterotopic bone formation within fascial tissue. We present a case of a 23-year-old female with a nontraumatic painful mass of the left proximal thigh identified as ossifying fasciitis, a lesion that must be considered in the differential diagnosis of soft tissue tumors.

Aggressive fibromatosis near the incision after cervical spinal cord ependymoma: A case report

Aggressive fibromatosis (AF), also known as ligamentoid fibromatosis and desmoid tumor, is a fibroblast clonoproliferative lesion located in the deep soft tissue. The present study reports the case of a 36-year-old female with AF who underwent cervical spinal cord ependymoma surgery. AF developed in the soft tissue of the neck adjacent to the incision site. The size of the neck AF increased rapidly over 2 years, and due to discomfort, the patient underwent initial surgical resection without any other combined treatment methods. When the patient was routinely reviewed at 6 months post-surgery, a recurrence of AF of the neck was found. The patient was recommended surgical resection and radiotherapy. This case report should improve the understanding of clinicians with regard to AF, and help the diagnostic process and treatment plan.

Mesenchymal Tumors of the Breast: Fibroblastic/Myofibroblastic Lesions and Other Lesions

Mesenchymal breast tumors are a rare and diverse group of tumors that present some of the most challenging cases for multidisciplinary breast cancer teams. As a result of overlapping morphologies and a lack of large-scale studies on these tumors, practices are often heterogeneous and slow to evolve. Herein, we present a non-systematic review that focuses on progress, or lack thereof, in the field of mesenchymal breast tumors. We focus on tumors originating from fibroblastic/myofibroblastic cells and tumors originating from less common cellular origins (smooth muscle, neural tissue, adipose tissue, vascular tissue, etc.).

Nodular fasciitis of the breast: clinicopathologic and molecular characterization with identification of novel USP6 fusion partners

Nodular fasciitis is a benign, self-limited, pseudosarcomatous neoplasm that can mimic malignancy due to its rapid growth, cellularity, and mitotic activity. Involvement of the breast is rare and diagnosis on biopsy can be challenging. In this largest series to date, we examined the clinicopathologic and molecular characteristics of 12 cases of nodular fasciitis involving the breast/axilla. All patients were female, with a median age of 32 years (range 15-61). The lesions were 0.4 to 5.8 cm in size (median 0.8). All cases presented as palpable masses, and two patients had overlying skin retraction. Microscopically, lesions were relatively well-circumscribed nodular masses of bland myofibroblastic spindle cells within a variably myxoid stroma. Infiltrative growth into adipose tissue or breast epithelium was frequent. Mitotic figures were present in all cases, ranging from 1 to 12 per 10 high-power fields (median 3). Immunohistochemically, all cases expressed smooth muscle actin and were negative for pan-cytokeratin, p63, desmin, CD34, and nuclear beta-catenin. Targeted RNA sequencing performed on 11 cases identified USP6 gene fusions in eight; one additional case was positive by break-apart fluorescence in situ hybridization. The common MYH9-USP6 rearrangement was detected in four cases; another case had a rare alternative fusion with CTNNB1. Three cases harbored novel USP6 gene fusions involving NACA, SLFN11, or LDHA. All fusions juxtaposed the promoter region of the 5' partner gene with the full-length coding sequence of USP6. Outcome data were available for eight patients; none developed recurrence or metastasis. Five patients elected for observation without immediate excision, and self-resolution of the lesions was reported in three cases. Albeit uncommon, nodular fasciitis should be considered in the differential diagnosis of breast spindle cell lesions. A broad immunohistochemical panel to exclude histologic mimics, including metaplastic carcinoma, is important. Confirmatory detection of USP6 rearrangements can aid in classification, with potential therapeutic implications.

Nodular fasciitis of the breast: Report of two cases illustrating the diagnostic implications for USP6 gene rearrangement and brief review of the literature

Nodular fasciitis is a benign, self-limited, pseudosarcomatous neoplasm that is cytogenetically characterized by recurrent USP6 gene rearrangement. Involvement of the breast by nodular fasciitis is very rare with only a few documented cases. It can clinically, radiologically and histologically mimic a malignancy, posing significant diagnostic challenges to clinicians, radiologists, and pathologists. In this study, we report 2 cases of nodular fasciitis occurring in the female breast, reviewing the literature and emphasizing the application of fluorescence in situ hybridization analysis of USP6 gene rearrangement in its diagnosis and differential diagnosis.

Practical approach to diagnosis of bland-looking spindle cell lesions of the breast

The diagnosis of bland-looking spindle cell lesions of the breast is often challenging because there is a close morphological and immunohistochemical overlap among the different entities. The present review will discuss reactive spindle cell nodule/exuberant scar, nodular fasciitis, inflammatory pseudotumor, myofibroblastoma (classic type), lipomatous myofibroblastoma, palisaded myofibroblastoma, benign fibroblastic spindle cell tumor, spindle cell lipoma, fibroma, leiomyoma, solitary fibrous tumor, myxoma, schwannoma/neurofibroma, desmoid-type fibromatosis, dermatofibrosarcoma protuberans, low-grade fibromatosis-like spindle cell carcinoma, inflammatory myofibroblastic tumor and low-grade myofibroblastic sarcoma arising in the breast parenchyma. The pathologist should be aware of each single lesion to achieve a correct diagnosis to ensure patient a correct prognostic information and therapy. Accordingly representative illustrations and morphological/immunohistochemical diagnostic clues will be provided.

The role of deubiquitinating enzymes in gastric cancer

The epigenetic regulation of gene expression (via DNA methylation, histone modification and microRNA interference) contributes to a variety of diseases, particularly cancer. Protein deubiquitination serves a key role in the mechanism underlying histone modification, and consequently influences tumor development and progression. Improved characterization of the role of ubiquitinating enzymes has led to the identification of numerous deubiquitinating enzymes (DUBs) with various functions. Gastric cancer (GC) is a highly prevalent cancer type that exhibits a high mortality rate. Latest analysis about cancer patient revealed that GC is sixth deadliest cancer type, which frequently occur in male (7.2%) than female (4.1%). Complex associations between DUBs and GC progression have been revealed in multiple studies; however, the molecular mechanism underpinning the metastasis and recurrence of GC is yet to be elucidated. Generally, DUBs were upregulated in gastric cancer. The relation of DUBs and tumor size, classification and staging was observed in GC. Besides, 5-yar survival rate of patients with GC is effeccted by expression level of DUBs. Among the highly expressed DUBs, specifically six DUBs namely UCHs, USPs, OTUs, MJDs, JAMMs and MCPIPs effect on this survival rate. Consequently, the association between GC and DUBs has received increasing attention in recent years. Therefore, in the present review, literature investigating the association between DUBs and GC pathophysiology was analyzed and critically appraised.

Giant Protruding Nodular Fasciitis of the Anterior Chest Wall Clinically Mimicking a Soft Tissue Sarcoma

Nodular fasciitis (NF) is a benign reactive proliferation of myofibroblasts that predominantly occurs subcutaneously. Commonly, it presents as a rapidly growing swelling in 4-8 weeks. NF mostly occurs in adults aged 20-50 years and usually has a diameter < 3‐4 cm. Giant NF with a diameter > 4 cm is rare. Owing to its rapidly growing nature, a precise clinical diagnosis is difficult; it is frequently misdiagnosed as an aggressive or malignant tumor. Herein, we present the case of a 15-year-old male who presented with a large protruding mass on the anterior chest wall. The tumor appeared clinically malignant as it was protruding and had doubled in size within a few weeks, reaching approximately 8 × 6 cm. Furthermore, the tumor separated and fell off spontaneously due to its large size. As the remaining tumor continued to grow rapidly, surgery was performed. Following wide tumor resection, no recurrence, metastases, or other complications were noted 1 year postsurgery. NF was diagnosed after pathological evaluation, including immunohistochemical analysis, molecular genetic testing, and cytogenetic testing via fluorescence in situ hybridization analysis. Knowledge of the atypical clinical course and a combination of histopathological examinations are necessary to accurately diagnose NF.

Ossifying fasciitis at an extraordinary site - a case report and analysis of diagnostic pitfalls

Ossifying fasciitis is a very rare disease of reactive character; however, it can mimic malignant lesions, especially osteosarcoma. We report a case of a 30-year-old woman, who experienced a rapidly growing painful lesion of the left knee joint, preceded by a trauma. The tumor was resected, and the histopathological image suggested a malignant lesion with features of an osteosarcoma. A detailed correlation with a clinicopathological and radiological analysis led to the final diagnosis of ossifying fasciitis at an extraordinary site of patellar retinaculum. Our case shows that the close similarity between ossifying fasciitis and osteosarcoma may be challenging.

Benign spindle cell lesions of the breast: a diagnostic approach to solitary fibrous tumour, nodular pseudoangiomatous stromal hyperplasia and nodular fasciitis

Benign spindle cell lesions of the breast include neoplastic and reactive entities that are diagnostically challenging given their rarity and similar histomorphology. Accurate diagnosis on percutaneous core biopsy within this category is essential as some lesions require excision and surveillance, whereas others may be observed. We present three cases of rare benign spindle cell lesions of the breast that reflect the diversity of this group: solitary fibrous tumour, nodular pseudoangiomatous stromal hyperplasia and nodular fasciitis. Through these cases, we discuss the associated differential diagnosis and demonstrate how emerging ancillary studies can be integrated into a diagnostic approach. We highlight distinctive clinical and histopathological features and summarise recent updates to the clinical management of these lesions. An organised approach to the broad differential of spindle cell lesions is essential for appropriate diagnosis and treatment.