Desmoplastic fibroma of the Mandible with unusual histopathological features.

Desmoplastic fibroma (DF) is a rare myofibroblastic primary tumor of bone that histologically and biologically mimics the extra-abdominal desmoid tumor of soft tissue. The surgical management of this tumor has been a matter of controversy and its recurrence has been a matter of clinical relevance. In this case report, we describe an unusual case of DF in a 15-year-old male patient who presented with a slow-growing mass in the right posterior mandibular region of 2 years duration. The presence of areas mimicking Giant cell angiofibroma (GCA) is the highlight of the case. The possibility of misdiagnoses is more in early lesions since the available literature shows that immunohistochemistry (IHC) is not of much benefit while differentiating DFs from other spindle cell lesions.

Molecular Alterations in Pediatric Fibroblastic/Myofibroblastic Tumors: An Appraisal of a Next Generation Sequencing Assay in a Retrospective Single Centre Study.

BACKGROUND: Pediatric fibroblastic/myofibroblastic tumors (PFMTs) can be challenging to definitively classify. Large case series or diagnostic updates have not been recently published despite identification of molecular alterations that could improve diagnostic accuracy. Our review of the literature found that over two-thirds of the more than 30 types of PFMTs harbor recurrent molecular alterations. We performed an institutional review of PFMTs to highlight limitations of a predominantly morphological classification, and evaluated the utility of a next-generation sequencing assay to aid diagnosis. METHODS: PFMTs identified over a period of 12 years were reviewed, categorized per the new WHO classification, and tested using the Oncomine Childhood Cancer Research Assay. RESULTS: Eighty-seven specimens from 58 patients were reviewed; 50 were chosen for molecular analysis, 16 (32%) lacking definitive classification. We identified alterations, some novel, in 33% of assayed cases. Expected alterations were identified for most known diagnoses and mutations were identified in 6 of 16 tumors (38%) that were initially unclassified. CONCLUSION: We confirmed a significant subset of PFMTs remain difficult to classify using current criteria, and that a combined DNA/RNA assay can identify alterations in many of these cases, improving diagnostic certainty and suggesting a clinical utility for challenging cases.

Fibroma de fibroblastos gigantes: presentación de 122 casos / Giant Cell fibroma: presentation of 122 cases

El fibroma de fibroblastos gigantes (FFG), conocido también como fibroma de células gigantes, es una pápula o nódulo asintomático localizado en la encía, paladar y lengua, es del mismo color que la mucosa adyacente, de base sésil o pediculada, con superficie lisa o papilar que por lo general mide menos de 1 cm. Objetivo: Identificar las características demográficas e histopatológicas de los casos de FFG de un laboratorio privado de patología bucal en la Ciudad de México. Material y métodos: Se obtuvieron los datos de edad, sexo, diagnóstico presuntivo y definitivo de 122 casos de FFG de 2004 a 2019 con un total de 7,681 muestras. Se describe su distribución por edad, sexo y localización. Resultados: El rango de edad obtenido es de 1 a 84 años, con un promedio de X = 38 años, se presenta con mayor frecuencia en la segunda década de vida, con una razón de 1.6:1 mujer a hombre. La localización más frecuente es en lengua (46%); sin embargo, sólo 49.1% de los estudios especificaban este dato. Conclusión: La importancia de esta lesión es que clínicamente se parece a otras patologías de tejido fibroso, por lo tanto, se debe tener presente al FFG como diagnóstico diferencial (AU)

Giant cell fibroma (GCF) is an asymptomatic papule or nodule that is similar in color to the surrounding mucosa, with a sessile or pedunculated base. It is usually less than 1 cm in size and it features a smooth or papillary surface. Objective: To identify the demographic and histopathological characteristics of GCF cases in a private oral pathology laboratory in Mexico City. Material and methods: Data on age, sex, as well as on presumptive and definitive diagnosis of 122 GCF cases were obtained from 2004 to 2019 with a total of 7,681 samples. Its distribution by age, sex and localization is described. Results: The age range obtained is from 1 to 84 years, with a mean age of 38 years. Frequently during the second decade of life, the female to male ratio is 1.6:1. The most frequent location is the tongue (46%), however, only 60 of 122 studies specified this data. Conclusion: Since this lesion clinically resembles another fibrous tissue pathology, it is warranted to have prior knowledge on its clinical characteristics, as GCF should be regarded as a differential diagnosis (AU)

Nonossifying Fibromas: A Computed Tomography-based Criteria to Predict Fracture Risk.

BACKGROUND: Nonossifying fibroma (NOF) is the most common benign osseous lesion in children; however, our understanding of which lesions progress to a fracture remains unclear. In this study, we seek to formulate a classification system for NOFs to assess for fracture risk and determine what this classification system tells us regarding fracture risk of the distal tibia and distal femur NOFs. METHODS: Charts were retrospectively reviewed for patients with NOFs. A 4-point criteria was created and used to calculate fracture risk for distal tibia and distal femur NOFs. The analysis included incidence, specificity, and sensitivity. RESULTS: One point was given for each of the following findings on computed tomography (CT) scan: (1) >50% width on coronal view; (2) >50% width on sagittal view; (3) any cortical breach; (4) lack of a neocortex. In total, 34 patients with NOFs of the distal tibia had CT scans, of which 14 fractured. Zero with a 0- or 1-point score fractured, 2 with a 2-point score fractured (20%), 4 with a 3-point score fractured (44%), and 8 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 100%, 85.7%, and 57.1%, respectively, and specificities were 71.4%, 71.4%, 80%, and 100%, respectively. A total of 41 patients with NOFs of the distal femur had CT scans, of which 5 fractured. Zero with a 0-point score fractured, 1 with a 1-point score fractured (4%), 0 with a 2-point score fractured, 1 with a 3-point score fractured (20%), and 3 with a 4-point score fractured (100%). Sensitivities of 1-, 2-, 3-, and 4-point scores were 100%, 80%, 80%, and 60%, respectively; and specificities were 60%, 87.8%, 90%, and 100%, respectively. CONCLUSIONS: Our 4-point CT criteria is easy to apply and identifies patients at high risk of fracture, helping surgeons make decisions regarding treatment. LEVEL OF EVIDENCE: Level IV-prognostic study.

Fibroma odontogénico central: reporte de dos casos / Central odontogenic fibroma: report of two cases

El fibroma odontogénico central es una lesión poco común dentro de los tumores odontogénicos. La variante central incrementa esta rara incidencia, representando solamente 1.5 por ciento de éstos. En el presente artículo se reportan dos casos de fibroma odontogénico central en la región maxilar, así como el tratamiento empleado para la resección del mismo y la reconstrucción de la región, mediante técnica de injerto óseo, malla de titanio y osteosíntesis...

Optimal Percent Myxoid Component to Predict Outcome in High-Grade Myxofibrosarcoma and Undifferentiated Pleomorphic Sarcoma.

BACKGROUND: Myxofibrosarcoma and undifferentiated pleomorphic sarcoma (UPS) are aggressive, genetically complex sarcomas. The minimum myxoid component used as a criterion for myxofibrosarcoma varies widely, so we determined the optimal myxoid component cutpoints for stratifying outcomes of UPS and myxofibrosarcoma. We also analyzed clinicopathologic factors associated with outcome. METHODS: Review of a prospective, single-institution database identified 197 patients with primary, high-grade extremity/truncal myxofibrosarcoma or UPS resected during 1992-2013. Histology was reviewed and percent myxoid component determined for each tumor. Disease-specific survival (DSS) and distant recurrence-free survival (DRFS) were analyzed using the Kaplan-Meier method, log-rank test, and Cox regression. RESULTS: Median follow-up for survivors was 6.4 years. In minimum p value analysis of myxoid component, the best cutpoint for both DSS and DRFS was 5% (adjusted p ≤ 0.001), followed by 70%. Therefore, sarcomas with <5% myxoid component (n = 69) were classified as UPS and those with ≥5% myxoid component (n = 128) as myxofibrosarcoma. Five-year DRFS was 24% for UPS, 51% for 5-69% myxoid component myxofibrosarcoma, and 65% for ≥70% myxoid component myxofibrosarcoma. Myxoid component, tumor size, and age were independently associated with DSS; myxoid component and tumor size were associated with DRFS. Only tumor site was associated with local recurrence. CONCLUSIONS: Percent myxoid component and tumor size are the two most important predictors of DSS and DRFS in high-grade myxofibrosarcoma and UPS. A 5% myxoid component cutpoint is an improved criterion for classifying myxofibrosarcoma. Myxoid component-based classification improves stratification of patient outcome and will aid in selection of patients for systemic therapy and clinical trials.

Low-grade fibromatosis-like spindle cell carcinomas of the breast are molecularly exiguous.

BACKGROUND: Low-grade fibromatosis-like spindle cell carcinomas are very rare breast carcinomas comprising <0.5% of all breast cancers. They demonstrate immunohistochemical (IHC) features of basal-like/metaplastic breast carcinomas, but the underlying molecular characteristics are unknown. We hypothesised that, as with IHC similarities, there may be common genomic alterations between spindle cell and basal-like/metaplastic carcinomas. METHODS AND RESULTS: Genomic mutational profile and genomic copy number aberration (CNA) analyses were performed on three cases of this unusual entity, and findings were compared with that reported for basal-like/metaplastic breast carcinomas. Copy number analyses by molecular inversion probe assays of the three spindle cell carcinoma samples revealed little overall genomic CNAs with only minor changes identified (fraction of the genome altered; 1.3%-6.4%), but with a common 9p21.3 loss in 2 out of 3 samples, with CDKN2A (p16) being a likely candidate. No areas of commonality were identified in an in silico analysis compared with publically available basal-like/metaplastic carcinoma copy number data. CONCLUSIONS: These tumours are characterised by low genomic instability, and share no CNAs with other metaplastic carcinomas. These findings favour this entity being a unique group genotype and belie their apparent homogeneous morphology and phenotype.

Renal leiomyoma: a contemporary multi-institution study of an infrequent and frequently misclassified neoplasm.

Renal leiomyoma is an exceptionally rare benign mesenchymal tumor of the kidney predominantly arising in proximity of the renal capsule or pelvis. Its rarity and nonspecific clinical and imaging features may lead to radical or partial nephrectomy on the basis of preoperative suspicion of renal cell carcinoma. The diagnosis of renal leiomyoma is challenging because of the histologic overlap with lipid-poor angiomyolipoma (AML). We conducted a multi-institution study to characterize renal leiomyoma in greater detail. We collected and reviewed 24 cases diagnosed initially as renal leiomyoma in 10 institutions from North America, Canada, and Europe. Immunohistochemical expression of desmin, HMB-45, estrogen receptor (ER), progesterone receptor (PR), and cathepsin K was evaluated. Upon central review, 9 tumors were classified as renal leiomyoma, whereas the remaining were reclassified as AML (n=13), myolipoma (n=1), and medullary fibroma (n=1). All renal leiomyomas were solitary and occurred in female patients (mean age 63 y; range, 44 to 74 y). Tumor size ranged from 0.6 to 7.0 cm (mean 2.9 cm); 7 originated from the renal capsule or the subcapsular area and 1 from a large vessel in the renal sinus. All leiomyomas were diffusely positive for desmin and negative for HMB-45 and cathepsin K; 6/9 (67%) showed diffuse ER and PR expression, and 1 case showed focal ER positivity only. Renal leiomyoma should be included in the histologic differential diagnosis of solid renal masses, particularly in perimenopausal women. The main differential diagnosis is with lipid-poor AML, and cathepsin K plays a key role in distinguishing these 2 lesions.

[Differential diagnostics of sebaceous tumors]. / Differenzialdiagnostik der Talgdrüsentumoren.

Sebaceous tumors are epithelial tumors with a differentiation towards sebaceous adnexal structures of the skin. They imitate the epithelial cells of mature sebaceous glands, sebaceous ducts, immature (embryonic) sebaceous structures or sebaceous glands that are not stimulated by hormones (mantle structures). This article explains the classification of sebaceous tumors on the basis of the normal histology of sebaceous glands. Clinical and histopathological criteria are given for the most important sebaceous tumors. The differential diagnosis of sebaceoma, sebaceous adenoma and various types of sebaceous carcinoma is emphasized. The importance of a specific diagnosis of adnexal tumors is demonstrated by tumor-associated syndromes with involvement of other organs (e.g., Muir-Torre syndrome and Birt-Hogg-Dubé syndrome). Furthermore, conceptional controversies, problems in differential diagnosis and the impact of immunohistochemical staining in the assessment of sebaceous tumors are considered.

Electrochemotherapy for the treatment of recurring aponeurotic fibromatosis in a dog.

This paper reports the clinical findings, histopathology, and clinical outcome of a rare case of aponeurotic fibromatosis in a dog. The dog was treated with 4 courses of electrochemotherapy using the drugs cisplatin and bleomycin. There was complete remission and the dog was still disease-free after 18 months.

Électrochimiothérapie pour le traitement de la fibromatose aponévrotique chez un chien. Cet article présente les résultats cliniques, l'histopathologie et le résultat clinique d'un rare cas de fibromatose aponévrotique chez un chien. Le chien a été traité avec 4 séries d'électrochimiothérapie utilisant les médicaments cisplatine et bléomycine. Il s'est produit une rémission complète et le chien était toujours exempt de maladie après 18 mois.(Traduit par Isabelle Vallières).

Familial multiple discoid fibromas: a look-alike of Birt-Hogg-Dubé syndrome not linked to the FLCN locus.

BACKGROUND: Previously, we proposed that familial multiple trichodiscomas (OMIM 190340) is distinct from Birt-Hogg-Dubé syndrome (BHD) (OMIM #135150). BHD is characterized by multiple fibrofolliculomas/trichodiscomas, lung cysts, pneumothorax, and renal cell cancer. Germline FLCN mutations can be detected in most but not all BHD families. OBJECTIVE: We sought to evaluate familial multiple trichodiscomas at a clinical and genetic level. We now renamed this condition "familial multiple discoid fibromas" (FMDF) to emphasize the distinction from BHD. METHODS: In 8 additional families with an autosomal dominant pattern of multiple discoid fibromas we assessed the clinical findings and the histopathological features of skin lesions. FLCN germline mutation analysis was completed in 7 families. In two of these families segregation analysis was performed using polymorphic DNA markers in and around the FLCN locus. RESULTS: The clinical findings in FMDF are different from those in BHD with early onset of skin lesions, prominent involvement of the pinnae, and discoid fibromas without the follicular epithelial component characteristic of the fibrofolliculoma/trichodiscoma spectrum of BHD. In addition, there were no evident pulmonary or renal complications. In none of the families were pathogenic FLCN germline mutations identified. Using segregation analysis we could exclude involvement of the FLCN locus in the two kindreds tested. LIMITATIONS: The prevalence of FMDF is presently unknown. The underlying gene defect has not yet been identified. CONCLUSIONS: FMDF is clinically distinct from BHD and is not linked to the FLCN locus.

Odontomas: tratamiento quirúrgico / Odontomas: surgical treatment

Los odontomas son tumores benignos odontogénicos y de crecimiento lento, formados por células de naturaleza dentaria epiteliales y mesenquimales. La etiología de este tipo de lesión es desconocida, pero se asocian a causas de tipo traumático, procesos infecciosos, anomalías hereditarias e hiperactividad odontoblástica. Se presentan dos casos clínicos en donde podemos observar los diferentes tipos de odontomas existentes. Los mismos fueron tratados en el Servicio de Odontología del Hospital Materno Infantil de la Ciudad de Mar del Plata.

New or unusual dermatopathology tumors: a review.

As experience is acquired, there is a constant evolution in both terminology and understanding of various relatively newly described tumors in the realm of dermatopathology. Several mesenchymal tumors of the lower extremity have undergone various changes in nomenclature, molecular discoveries, and histologic grading. Examples include hemosiderotic fibrohistiocytic lipomatous lesion/pleomorphic hyalinizing angiectatic tumor; superficial acral fibromyxoma; and myxoinflammatory fibroblastic sarcoma. Primary cutaneous myoepithelioma is also a relatively newly described entity for which grading and classification continue to evolve. Finally, even our understanding of the classic granular cell tumor has expanded to include a non-neural variant. This article reviews the current nomenclature, emerging concepts, and differential diagnosis of these evolving entities.

Odontogenic fibroma, including amyloid and ossifying variants.

Sixty-five cases of odontogenic fibroma (OdonF) are herein presented having been segregated into peripheral, extra bony tumors (n = 40) and tumors arising in bone or centrally (n = 25). All cases were characterized microscopically by a fibrous proliferation that varied within and between cases in cellularity and collagen fibril diameter, with intermixed odontogenic epithelial islands and cords. All central lesions presented as well demarcated radiolucencies and resorption of contiguous tooth roots was a common finding. These intraosseous lesions were of the WHO type; the so-called nonWHO type was excluded as all lesions with this diagnosis were devoid of an epithelial component and could be reclassified as other soft tissue fibrogenic tumors. Neither the central tumors nor the peripheral lesions recurred following enucleation/curettage, with a mean follow-up of 4 and 3.4 years respectively. Three distinct microscopic variations were encountered in this series: (1) two cases of OdonF with giant cell reaction, (2) two instances of OdonF with ossifying fibroma; and (3) four instances of OdonF with odontogenic ameloblast-associated protein (ODAM), an amyloid-like protein found deposited adjacent to epithelial cords plus CD1a+/S-100+ Langerhans dendritic cells entwined around the epithelial element. A single instance of the odontogenic fibroma-like hamartoma/enamel hypoplasia syndrome has been included in this series.

Biology, classification, and management of recurrent myxofibrosarcoma 21 years after resection.

Soft-tissue sarcomas (STSs) are a heterogenous group of rare malignancies that have significant lifelong implications. Accepted management options include limb-sparing surgical resection and adjuvant radiation therapy. Here we present the case of a myxoid malignant fibrous histiocytoma, now termed a myxofibrosarcoma, which recurred 21 years after primary surgical resection. To our knowledge, this is the longest documented interval between initial management and recurrence of an STS. Significant changes have been made in classification guidelines and diagnostic methods over this 2-decade period. The pathogenesis of remote recurrence of STSs remains controversial and is discussed in this report.

[Expression of beta-catenin and estrogen receptor in desmoid-type fibromatosis].

OBJECTIVE: To detect the expression of beta-catenin and Estrogen Receptor in desmoid-type fibromatosis. METHODS: Nuclear beta-catenin expression was detected by immunohistochemistry in 77 lesions with desmoid-type fibromatosis and 171 other spindle cell lesions, including superficial fibromatosis (n = 18), nodular fasciitis (n = 36), keloid (n = 16), scar (n = 10), granulation tissue (n = 9), synovial sarcoma (n = 38), neufibroma (n = 13), solitary fibrous tumor (n =12), gastrointestinal stromal tumor (n = 10), low-grade myxofibrosarcoma (n = 3), low-grade fibromyxoid sarcoma (n = 3), and smooth muscle tumor (n = 10). In addition, the immunohistochemical expressions of ER-alpha, ER-beta and Ki-67 were examined in all of the lesions with desmoid-type fibromatosis. The nuclear immunohistochemical staining for nuclear beta-catenin and ER-beta was graded as high level ( > or = 25% of cells), low level (5%-25%) or none. RESULTS: High-level nuclear beta-catenin staining was detected in a very limited subset of tissue types, which included 70.1% of lesions with desmoid-type fibromatosis (54/77) and 6.3% of lesions with keloid (1/16). No high-level nuclear beta-catenin staining was seen in any of the other lesions. None of the lesions with desmoid-type fibromatosis expressed ER-alpha. However, 62 (80.5%) of the lesions with desmoids-type fibromatosis were positive in ER-beta, which included 52 (67.5%) with high-level expression, and 10 (13%) with low-level expression. The Spearman correlation analysis suggested that the expression of beta-catenin was positively correlated (r = 0.867, P < 0.05) with the expression of ER-beta. The lesions with desmoid-type fibromatosis had very low Ki-67 positive rate. The recurrence of desmoids-type fibromatosis was not correlated independently with beta-catenin, ER-beta or Ki-67. CONCLUSION: High-level nuclear beta-catenin staining serves as a useful diagnostic tool for desmoid-type fibromatosis. The high expression of ER-beta in desmoid-type fibromatosis provides a biological mechanism for the antiestrogenic compounds to treat fibromatosis. There might exists an interaction between beta-catenin and ER-beta. Beta-catenin, ER-beta or Ki-67 can not predict the prognosis of desmoid-type fibromatosis.

Imaging patterns in elastofibroma dorsi.

INTRODUCTION: Elastofibroma dorsi is a rare pseudotumor of the soft tissues. Its clinico-radiologic characteristics lead to a correct diagnosis. MATERIAL AND METHODS: We followed 43 patients with elastofibroma dorsi with a confirmed histological diagnosis or on the basis of typical imaging pattern (ultrasound, CT, MR) confirmed by evolution. RESULTS: Elastofibroma is prevalent in females, its onset occurs around 60 years of age and is most frequently localized in the deep subscapular region (93%), bilateral in 54% of cases. In 7% it was found in an atypical isolated suprascapular region, in 7% it was synchronous to that in the subscapular region. Four ultrasound patterns were detected: Type I (54%) inhomogeneous fasciculated, Type II (22%) inhomogeneous aspecific, Type III (15%) hyperechogeneous, Type IV (9%) hypoechogeneous. Three patterns were detected at CT and MR: Type A (84%) inhomogeneous fasciculated corresponding to Types I and III and partially to Type II ultrasound pattern, Type B (8%) inhomogeneous aspecific corresponding to Type II ultrasound pattern; Type C (8%) homogeneous isodense or isointense to the muscle corresponding to Type IV ultrasound pattern. CONCLUSION: A solid, slow-growing lesion, in the deep periscapular region in females aged between 50 and 60 years, with a typical fasciculated pattern is pathognomonic of elastofibroma dorsi and bilateral location convalidates diagnosis. Ultrasound is sufficient to orientate diagnosis. CT and/or MR are reserved only for non-fasciculated ultrasound patterns, when site is atypical or in candidates for surgery. Biopsy is reserved only in cases where integrated imaging shows a non-fasciculated pattern to differentiate it from other malignant lesions.

Juvenile hyaline fibromatosis and infantile systemic hyalinosis: a unifying term and a proposed grading system.

BACKGROUND: It has been suggested that juvenile hyaline fibromatosis and infantile systemic hyalinosis represent different severities of the same disease. OBJECTIVE: We sought to redefine these disorders clearly to establish a common inclusive terminology. PATIENTS: The study included two children with early onset of similar pink papulonodular skin lesions and marked gingival hyperplasia. The first case was characterized by flexion contractures of the large joints, fractures, persistent diarrhea, recurrent chest infections, and retarded physical growth. The second patient had large swellings on the scalp and knees without systemic involvement. RESULTS: Radiologic examination revealed fractures and osteolytic bone lesions in the first case, and soft tissue masses in the second case. Laboratory tests showed anemia in both cases, and hypogammaglobulinemia, hypoalbuminemia, and electrolyte imbalance in the first case. Histopathological and ultrastructural evaluation demonstrated hyalinized fibrous tissue in the dermis in both cases. LIMITATIONS: Genetic studies were unavailable. CONCLUSION: Juvenile hyaline fibromatosis and infantile systemic hyalinosis share many common features that strongly support consideration of these conditions as different expressions of the same disorder. We propose a common term, "hyaline fibromatosis syndrome," which can be divided into mild, moderate, and severe subtypes.

Types of tumors and outcome of treatment of 12 patients with nonmalignant fibrosing tumors in the pediatric hand.

Nonmalignant fibrosing tumors in the pediatric hand or juvenile fibromatoses are uncommon and so may be a challenge to the clinician. We propose a diagnostic and treatment approach to nonmalignant fibrosing tumors of the pediatric hand based on a review of 12 patients who presented with 16 distinct hand lesions. We performed a retrospective 7-year chart review of 12 pediatric patients all with nonmalignant fibrosing conditions of the hand. All patients were operated on by a single surgeon (D.N.) and all samples were reviewed by a single pathologist (E.P.). Twenty-eight surgical procedures were performed on 12 patients. Lesions were classified by location (7 palmar, 9 dorsal) as well as clinicopathologic characteristics. It is imperative to have a broad differential when entertaining the diagnosis of juvenile fibromatosis. Most important, a diagnosis of true cancer must be ruled out. Other mimickers of this process (eg, juvenile rheumatoid arthritis) must also be considered. Most evaluations begin with magnetic resonance imaging and biopsy but a careful history is, as always, a key part of the evaluation. Some lesions may be observed once a diagnosis has been made. When surgical excision is indicated, wide resection is necessary. This may then require flap reconstruction with tendon and joint repair.