Benign Tumors Research Articles

Masson tumor of the right atrial appendage presenting as cardiac tamponade: a case report

BackgroundIntravascular papillary endothelial hyperplasia (Masson tumor) is a rare, benign vascular tumor characterized by the proliferation of endothelial cells within blood vessels. While it typically affects the skin and subcutaneous tissues, it can occasionally appear in unusual locations.Case presentationWe report a rare case of Masson tumor located in the right atrial appendage of a healthy individual. This case was complicated by atrial wall rupture and subsequent cardiac tamponade. The tumor was successfully resected under cardiopulmonary bypass.ConclusionThis case highlights a rare occurrence of Masson tumor in the heart, emphasizing the importance of prompt surgical intervention to prevent life-threatening complications such as cardiac tamponade.

Synchronous primary ovarian tumours in postmenopausal women: A rare case report and literature review

The reported incidence of synchronous primary cancers of genital tract is 1-2%, among this synchronous primary ovarian tumour is rarest. Herein, a postmenopausal woman, who had previously undergone abdominal hysterectomy, presented with vague lower abdominal pain persisting for six months. A computed tomography scan confirmed the presence of an 8.1 x 8.2 cm cyst on her right ovary. Despite her CA125 levels being normal, she was scheduled for laparoscopic cystectomy. During the surgery, the left ovary was found to be enlarged, prompting bilateral salpingo-oophorectomy. Histological analysis revealed a serous cystadenoma in the left ovary and a mucinous cystadenoma in the right ovary.Most reported synchronous ovarian tumors are malignant, with only a few cases of benign synchronous ovarian tumors documented in the literature. Early diagnosis and reporting of such cases are crucial for improving our understanding of synchronous ovarian neoplasms, which can impact management strategies and help prevent complications.

Multiple morcelloma of the peritoneal cavity: a case report

Introduction. Uterine fibroids are benign monoclonal hormone-sensitive tumors arising from smooth muscle cells of the cervix or body uterus. Myomectomyhas become a treatment «golden standard» upon transition to the strategy of organ-preserving surgery. The introduction of morcellation into wide clinical practice allowed to expand the indications for laparoscopic myomectomy, which is usually much better tolerated by patients due to lower invasiveness, short period of rehabilitation and low blood loss. However, the use of morcellators along with the obvious advantages has also specific complications particularly emergence of iatrogenic parasitic fibroids of the abdominal cavity upon improper surgery technique.Aim: analysis of a clinical case of multiple morcelloma.Case presentation. Female patient I., 57 years old, underwent laparoscopic myomectomy in 2003. In 2023 during a routine examination at the Central Clinical Hospital «RZD-Medicine» multiple asymptomatic iatrogenic fibroids of the abdominal cavity were revealed. The patient underwent planned surgical intervention to remove all abnormal masses.Results. During the revision upon surgical intervention, a node of 1.5×1.5 cm was found on the parietal peritoneum along the left anterior wall, as well as a node of 1.5×1.5 cm on the parietal peritoneum along the right anterior wall. There was also observed a 2×3 cm node at the edge of the omentum. In the left and right side of peritoneum of the sacro-uterine ligament, there were found nodes of up to 1 cm in size. In the area of the small intestinal mesentery, a dense node of 4.5 cm was observed 70 cm away from the ileocecal valve. Due to small size, all the fibroids were extirpated and removed from the abdominal cavity without morcellation, complete hemostasis was performed. No complications were noted during postoperative period.Conclusion. Iatrogenic fibroids are quite rare but nevertheless a potential complication of laparoscopic myomectomy. Gynecologists should pay special attention to follow proper technique upon surgical intervention. Morcellation and subsequent extraction of fibroids should be performed strictly with use of airtight container to avoid ingress of myomatous tissue into the abdominal cavity followed by emergence of iatrogenic fibroids.

Pregnancy and Aggressive Angioma: A Very Rare Entity: Case Report and Literature Review

Vertebral hemangiomas (VH) are common benign tumors, often asymptomatic. Their clinical presentation during pregnancy is rare. We report the case of a 38-year-old woman at 37 weeks of pregnancy, admitted for progressive paraplegia caused by an aggressive VH at the D5 level. MRI revealed spinal cord compression, necessitating a cesarean section followed by laminectomy and cementoplasty. The growth of VH during pregnancy is facilitated by hemodynamic and hormonal changes. Treatment involves surgery, with embolization as an option to reduce bleeding, and radiotherapy in the postpartum period. This rare case highlights the importance of early diagnosis and multidisciplinary management.

Comparison of histopathological diagnoses of ENT diseases in the COVID-19 pandemic with other periods

Abstract OBJECTIVE. It is aimed to reveal the frequency of histopathological diagnosis in ENT diseases during the COVID-19 period and whether it is different from diagnoses in other periods. MATERIAL AND METHODS. The files of 1442 patients diagnosed with pathological material in the ENT clinic between 2017 and 2022 were retrospectively scanned. Two groups were created: the 1st group of patients between 2017-2019 (non-COVID-19 period) (Group 1) and the 2nd group of patients between 2020-2022 (COVID-19 period) (Group 2). RESULTS. Pathological samples were sent from 1163 patients in Group 1 and from 279 patients in Group 2. Of 1442 patients, 815 were male and 627 were female, and the mean age was 25 (3-94 years). There was a statistically significant difference between the groups in terms of age (p=0.001). There was no significant difference in terms of gender (p=0.756). The most common histopathological diagnoses in both periods were chronic tonsillitis lymphoid hyperplasia (bilateral tonsillectomy + adenoidectomy) (19.5%), chronic inflammation lymphoid hyperplasia (adenoidectomy) (19.3%) and nasal polyp (19.2%). The incidence of malignant tumors was found to be 1.4% in Group 1 and 2.8% in Group 2. The incidence of benign tumors was found to be 7.6% in Group 1 and 12.8% in Group 2. In terms of frequency, the ratio of malignant and benign tumors was higher in Group 2. CONCLUSION. The number of patients with histopathological diagnoses decreased due to the decrease in hospitalizations during the COVID-19 period. Delayed diagnosis in malignant pathologies significantly worsens the prognosis. All these results show that new cancer diagnostic strategies are needed for epidemic diseases such as COVID-19.

Management of large Trigeminal Schwannoma: long-term oncologic and functional outcome from a multicentric retrospective cohort.

Trigeminal schwannoma (TS), though a rare and benign tumor, becomes a significant surgical challenge due to its intricate location. This study aims to detail the long-term functional outcomes and tumor control post-surgical resection. We analyzed a multicentric retrospective cohort of 39 patients operated on for a TS in five tertiary centers between January 1993 and July 2022. Six TS (15%) were in the middle fossa (type M), two (5%) in the posterior fossa (type P), and two (5%) were extracranial (type E). Twenty-nine (75%) were Dumbbell shape: Eighteen (47%) were MP type, seven (18%) were MPE type, and four (10%) were ME type. Fifth nerve symptoms were the foremost preoperative complaint: hypesthesia (51%), trigeminal neuralgia (36%), and paresthesia (30%). We report a favorable evolution course for 61% of preexisting deficits (half of patients with preoperative paresthesia and neuralgia improved while only 5% of preoperative hypesthesia improved). Postoperative hypesthesia was the most frequent de novo deficit 14 (74%) and resolved in solely half the cases. Various approaches were used according to tumor type. Gross total resection (GTR), Subtotal resection (STR), and partial resection (PR) were achieved in respectively 33% (N = 13), 10% (N = 4), and 56% (N = 22) of patients. The mean clinical and radiological FU was 63months (12 - 283months). GTR led to no sign of recurrence (mean FU: 60months - range: 12-283months). For STR or PR (67%): 23 (88%) were assigned to a Wait-&-rescan policy (WS group) which offered stability in 70% (N = 16). Three cases (8%) underwent a complementary GKS (GammaKnife) on the residual lesion (GK group) without tumor change. For large TS, the completeness of resection must consider the potential functional burden of surgery. With giant infiltrating lesions, a strategy of planned subtotal resection, complemented by radiosurgery, either complementary or uppon regrowth, may provide similar oncological outcomes.

LW-MorphCNN: a lightweight morphological attention-based subtype classification network for lung cancer

Abstract Lung cancer is generally considered one of the most deadly cancers globally. If it can be identified early and diagnosed correctly, the survival probability of patients can be significantly improved. In this process, histopathological examination is a commonly used method for diagnosing and detecting lung cancer. It is crucial to accurately identify lung cancer subtypes from histopathological images, as this helps doctors formulate effective treatment plans. However, the visual inspection in histopathological diagnosis requires a large amount of time and also depends on the subjective perception of clinicians. Therefore, this paper proposes a lightweight lung cancer subtype classification network based on morphological attention (LW-MorphCNN), which is used to automatically classify the histopathological images of benign lung tumors, ADC (adenocarcinoma), and SCC (squamous cell carcinoma) provided in the public dataset LC25000 (Lung and Colon). This paper takes histopathological images as input and conducts a comparative analysis with classic networks such as VGG16, VGG19, DenseNet121, and ResNet50, as well as existing classification methods proposed in the same work. The network proposed in this paper is superior to other networks in terms of parameter quantity and performance, with an accuracy rate and F1 - score reaching 99.47% and 99.44% respectively. Clinicians can install the provided LW-MorphCNN in the hospital to confirm the diagnosis results.

Red Cell Distribution Width and the Early Detection of Ovarian Cancer

Ovarian Cancer is a leading cause of mortality and morbidity, lacking clinical manifestations and effective early diagnostic techniques. The majority of cases are diagnosed at later stages; however, asymptomatic screening is currently not recommended due to its low predictive value and invasive nature. Furthermore, the current CA-125 biomarker used to monitor Ovarian Cancer is elevated in other conditions, including endometriosis or pelvic inflammation. Red Cell Distribution Width (RDW) is a parameter measured in a complete blood count, measuring the range of variation in red blood cell size and heterogeneity of red blood cell volume. RDW levels positively correlate with Ovarian Cancer progression, additionally increased in Ovarian Cancer groups compared to benign ovarian tumour groups. RDW possesses high sensitivity in distinguishing between cancerous and benign ovarian tumours, in line with ideal screening method standards. RDW additionally shows potential as a diagnostic biomarker in combination with other blood parameters, such as hemoglobin. The hemoglobin-RDW ratio (HRR) acts as an independent predictor of Ovarian Cancer stage. RDW’s mechanism of action is not fully elucidated but can be associated with iron/folic acid deficiency, ineffective hematopoiesis caused by chronic inflammation, or inflammatory cytokines such as IL-1 and IL-17. High RDW levels additionally possess prognostic value, acting as an indicator of low cumulative overall survival and poor chemotherapy responses in various cancers. Further research is needed on RDW’s mechanism of action and its implication as a marker in female cancers, particularly Ovarian Cancer, to implement effective early screening techniques and reduce fatalities.

Clinical, Histological, and HPV-Related Factors Associated to Diffuse Presentation of Exophytic Nasal Papillomas

Background: Sinonasal exophytic papillomas (SNEP) are benign tumours arising from nasal mucosa. Human papillomavirus (HPV) infection seems to be related to the aetiology of a fraction of SNEP cases. SNEP presentation can be focal (FSNEP) or diffuse (DSNEP), but factors related to focal or diffuse presentation have not yet been well ascertained. This study aimed to analyse clinical, histological, and HPV-related differences between FSNEP and DSNEP. Methods: A retrospective cohort of 18 patients with SNEP from our centre were evaluated. Demographic, clinical and follow-up data were collected. All samples were subject to histopathological evaluation, DNA quality control, HPV-DNA detection, and viral load assessment. Univariate analyses were performed to evaluate differences between FSNEP and DSNEP. Results: Twelve SNEP patients were included in the final analysis. Seven patients had a diffuse nasal presentation, being younger than patients affected with FSNEP (42.7 years vs. 65.2 years, p = 0.019). The nasal septum was significantly more affected in DSNEP than in FSNEP (85.7% vs. 20%, p = 0.029). HPV-DNA was detected more frequently (100%) in DSNEP (HPV11 in six cases, HPV6 in one case) than in FSNEP (40%, p = 0.045, HPV6 in two cases). The median viral load among HPV6-positive samples was 626.8 virus/cell for FSNEP and 80.2 for DSNEP, and among HPV11-positive samples was 1673.7 for DSNEP. Recurrences were more frequent in the diffuse than in the focal group (85.7% vs. 20%, p = 0.029). Conclusions: The diffuse presentation of SNEP seems to be related to younger patients, nasal septum involvement, HPV infection, mostly HPV11, and a higher risk of recurrence.

Improving the radiological prediction of surgical resection of nonfunctioning pituitary adenomas.

Nonfunctioning pituitary adenomas (NFPAs) are benign tumors growing in the sellar region. Total surgical excision of the lesion is recommended as the preferred treatment choice with preservation of adjacent structures. The objective is to establish a radiological score to predict the feasibility of NFPA total surgical excision. Patients with treatment-naïve NFPA who underwent a transsphenoidal approach and sellar magnetic resonance imaging (MRI) in the preoperative period and 3 months after surgery were included. Data on age, sex, tumor diameter, extrasellar extension, postoperative cure rates, and hormone and transcription factor expression were collected. A combined score was proposed based on Knosp and SIPAP classifications. We proposed 3 classification groups depending on the tumoral extension to the suprasellar, infrasellar, anterior and posterior directions of the sellar region. A total of 164 patients were included in the study, and 85 (52%) were female. Total excision was obtained in 46% (n = 75) of the patients. The majority of tumors were of gonadotrophic lineage (59%), followed by corticotrophic (17%) and other less common types. Largest tumor diameter was 6.8cm [mean 3.8cm (± 1.1cm)]. From the established groups, 10 patients were classified in Group I, of whom 8 (80%) patients underwent total excision, 115 patients were classified in Group II, of whom 58 (50%) underwent complete excision and 39 patients in Group III, of whom 9 (23%) underwent complete excision (p value < 0.001). The newly proposed score helps to determine the feasibility of total NFPA excision, allowing for better surgical planning and predictions of postoperative outcomes.

Thyroid cancer in a child with Cowden syndrome

Cowden disease (Cowden syndrome) refers to PTEN-associated hamartoma tumor syndromes. It arises due to a mutation in the phosphatase and tensin homolog gene, one of the main functions of which is cell cycle regulation. The presence of a mutation in the gene leads to uncontrolled cell growth, and patients have a lifelong increased risk of neoplasms of various degrees of malignancy. This article presents a clinical case of Cowden syndrome with an early debut at the age of 7 years. The combination of macrocephaly (SDS of head circumference &gt;2) with various skin manifestations (facial trichilemmomas, acral keratosis, papillomatous papules) and the presence of benign and/or malignant neoplasms are pathognomonic for Cowden syndrome. Of the malignancies, breast and thyroid cancer, colorectal cancer, renal cell carcinoma, and endometrial cancer are the most common. Thyroid carcinoma has been shown to have an earlier age of manifestation and often occurs already in childhood. This determines the need to screen patients with a proven mutation in the PTEN gene for nodal neoplasms from an early age. If surgical treatment is necessary, thyroidectomy remains preferable due to the frequent recurrence of nodules, as well as the uncertain potential for malignancy due to the low study of thyroid nodules in patients with mutations in the PTEN gene.

Chondroblastoma of Bone in Children: A Study of 3 Cases

Chondroblastoma is a benign bone tumor arising most often in the epiphyses of long bones. Nearly 90% occurred in patients between the ages of 5 and 25 years, but tumors were found in later adulthood and even in old age. A few chondroblastomas were predominantly cystic, and some contained zones that were indistinguishable microscopically from aneurysmal bone cysts. Conservative surgical removal, nearly always effective, should be thorough so as to minimize the risk of the occasional troublesome recurrence. Late sarcomatous change has been reported in a few cases whether radiation therapy was employed or not. We report a series of 3 boys with chondroblastoma, with an average age of 12 years. All our patients underwent biopsy for confirmation and then surgical treatment consisting of curettage of the lesion followed by bone autograft filling. The aim is to discuss the anatomoclinical and evolutionary aspects of this rare tumour, to evaluate the results of surgical treatment and to identify the factors influencing the rate of recurrence after treatment.

Aggressive bone tumours: What a radiologist can offer to the surgeon?

The complexity of aggressive bone tumours necessitates a comprehensive approach that combines radiological assessments with clinical and pathological findings. Radiologists offer valuable insights to surgeons throughout the diagnostic and therapeutic journey, enhancing the precision and efficacy of surgical interventions. Radiologists contribute to definitive diagnosis in the majority of benign and certain aggressive tumours, although the complexity of aggressive bone tumours often requires histopathological confirmation. They assist in characterizing tumours and evaluating their extension, providing critical information for treatment planning. Radiologists guide biopsy procedures, ensuring representative tissue samples while minimizing morbidity and the risk of tumour spread. In preoperative planning, radiologists construct detailed 3D reconstructions of tumours, aiding surgeons in strategizing surgical approaches and anticipating challenges. During surgery, radiologists offer intraoperative guidance through techniques like image fusion and intraoperative MRI, enhancing surgical precision. Post-surgical surveillance for tumour recurrence heavily relies on radiological imaging, with functional MR sequences providing valuable insights. Radiologists also play a significant role in image-guided therapeutic interventions for aggressive bone tumours, offering procedures like osteoplasty and ablation techniques for pain relief and tumour control. In conclusion, radiologists are indispensable members of the multidisciplinary team and offer expertise in diagnosis, biopsy guidance, preoperative planning, intraoperative guidance, post-surgical surveillance, and interventional therapy. Their collaborative efforts significantly optimize patient's outcome and quality of life.

Impact of fast-track on recurrence and malignant transformation of patients with inverted papilloma

Background Inverted papilloma is a benign epithelial tumour located in the sinonasal tract with a high recurrence rate and a potential of malignant transformation. From 2017, patients with IP were included in our fast-track regime similar to head and neck cancer patients, including follow-up at 2, 6, 12, 18 and 24 months after surgery, then yearly for a total of 5 years. Aims/objectives This study aims to compare the recurrence rate and malignant transformation of patients with IP treated at a university centre following the implementation of a fast-track regime including a close follow-up. Methods A retrospective study was performed on all patients with IP diagnosed between 2018 and 2022. Results The study included 125 patients, all surgically treated for IP. Eight patients (6%) also presented with SCC at the time of diagnosis. The recurrence rate of benign IP was 17%. Most tumours originated in the maxillary sinus (48/117, 41%). No cases of metachronous cancer were seen during the follow-up. Conclusions and significance The majority of recurrences (90%) occurred within the first 2 years after treatment. No cases of malignant transformation were seen in the follow-up period. The rigorous follow-up program potentially contributed to the detection of recurrence before malignant transformation.

Excision of a supergiant spinal schwannoma: illustrative case.

The authors report on a patient who presented with an extremely large presacral schwannoma and subsequent mass effect-induced hydronephrosis and kidney failure. To the authors' knowledge, this case represents the largest radiographically verified spinal schwannoma in the medical literature. The tumor presented here was more than three times as large as a typical giant schwannoma. While smaller presacral schwannomas are usually uncomplicated surgical cases, the supergiant schwannomas described here create significant surgical challenges. The extremely large size of this nerve sheath tumor introduced a level of surgical complexity not seen in most spinal schwannoma cases. The authors hope that this case informs surgeons regarding the approach to excision of giant spinal schwannomas. The resection of giant spinal schwannomas is likely to involve one or more lengthy surgeries, and the resection volume can be limited by excessive bleeding. Physicians approaching these large, benign spinal tumors should be aware of the challenges of surgery duration and hemostasis before approaching a tumor of this kind. https://thejns.org/doi/10.3171/CASE24224.

Management of Ovarian Cysts through Individualized Homoeopathic Medicine: A Case Series

AbstractOvarian cysts are common gynecological problems encountered by gynecologists in their day-to-day practice. They are benign growths arising from the ovary and occur in the reproductive age group. Conventional system of medicine usually opts for surgical procedures in such cases. Homoeopathic system of medicine is a specialized system that believes in individualization. This article reports five cases of suffering from ovarian cysts, who reported at Dr. D.P. Rastogi Central Research Institute, Noida, Uttar Pradesh, India. All the five cases were treated successfully with individualized homoeopathic medicines. Each patient received individualized homoeopathic medicine selected on the basis of the totality of symptoms using synthesis repertory with the help of RADAR software. Pre and post treatment ultrasongraphy USG reports were kept as evidence. The assessment of causal attribution of homeopathic treatment effect was performed using the Modified Naranjo Criteria for Homeopathy (MONARCH). Marked improvement was observed in all five cases, with complete resolution of the cysts along with symptomatic relief, which was evident by USG reports. The MONARCH scores were +9/13, +7/13, +8/13, +9/13, and +7/13, which indicate a positive causal attribution of homeopathy in relieving the symptoms. This case series suggests a significant role of individualized homeopathic medicines in the resolution of ovarian cysts and associated symptoms. The results obtained from this case series are encouraging.

NEDD4 Knockdown Suppresses Human Endometrial Stromal Cell Growth and Invasion by Regulating PTGS2-Mediated Ferroptosis in Endometriosis.

Endometriosis (EM) is a gynecological disease characterized by the benign growth of endometrial tissue outside the uterus. Upregulation of neuronally expressed developmentally downregulated 4 (NEDD4) has been reported to accelerate endometrial cancer progression. We explored whether abnormal expression of NEDD4 is correlated with EM. Endometrial tissue in patients without endometriosis was used to develop the original generation of endometrial stromal cells (ESCs). Different types of endometrial tissue of patients with endometriosis were used to measure the expression of NEDD4 by immunohistochemistry (IHC) and western blotting. Its biological functions in ESCs were investigated using a cell counting kit-8 assay, fluorescein diacetate (FDA) staining, and Transwell invasion assays. Additionally, its involvement in ferroptosis was assessed by measuring Fe2+, malondialdehyde (MDA), glutathione (GSH), and reactive oxygen species (ROS) levels and the expression of ferroptosis markers. Compared with normal controls, NEDD4 levels were significantly elevated in the endometrial tissue of patients with EM. Furthermore, NEDD4 expression was higher in the ectopic endometrium than in the eutopic endometrium. NEDD4 knockdown reduced the viability and invasive capacity of ESCs, increased Fe2+, MDA, and ROS levels, and decreased GSH content. Further analysis revealed that NEDD4 knockdown promoted ferroptosis in ESCs by increasing the expression of prostaglandin-endoperoxide synthase 2 (PTGS2). As an E3 ubiquitin ligase, NEDD4 reduced PTGS2 protein levels by accelerating its ubiquitination and subsequent proteasomal degradation. These findings suggest that inhibiting NEDD4 reduces ESC growth and invasion in EM by regulating PTGS2-dependent ferroptosis.

Plating after tumor curettage in human femora does not efficiently improve torsional stability ex vivo

BackgroundSurgical treatments of benign primary bone tumors of the femur face the challenge of limiting tissue damage and contamination while providing sufficient stabilization to avoid fracture. While no clear treatment guidelines exist, surgical treatment commonly consists of femoral fenestration and curettage with optional filling and plating of the defect. Mono- or bicortical plating of distal femoral defects aim to reduce fracture risk and have been shown to increase axial stability. However, it remains unclear whether plating increases torsional stability of the affected femur. Questions/purposesThis biomechanical study aimed to determine how much additional stability can be achieved by mono- or bicortical plating of femoral defects after fenestration. The following hypotheses were investigated: 1. Preventive plating of distal femur bone defects enhances torsional stability when compared to femoral fenestration alone. 2. A condition close to the intact (nonpathological) bone can be achieved by bone plating. 3. Defect shape influences torsional stability. Patients and methodsThiel embalmed human femora (n = 24) were left intact or subjected to the following surgical treatments (A) defect creation via fenestration, (B) defect with short monocortical plating, (C) defect with long bicortical plating. All femora were torsion tested in midstance position using pre-cycling and testing until failure. Quantitative computed tomography pre and post testing allowed bone mineral density calculation and crack path analysis. Finite element analysis provided insight into defect shape variations. ResultsTorsion experiments showed no relevant enhancement of torsional stability due to mono- or bicortical plating. There were no significant differences in maximum torque between unplated and plated femora with defect (defect: 35.38 ± 7.53 Nm, monocortical plating: 37.77 ± 9.82 Nm, bicortical plating: 50.27 ± 9.72 Nm, p > 0.05). Maximum torque for all treatment groups was significantly lower compared to intact femora (155–200 Nm, p < 0.001). Cracks originated predominantly from the proximal posterior corner of the defect and intersected with screw holes in plated femora. The influence of variations of the defect corner shapes had no significant influence on maximum torque and angle. ConclusionThis biomechanical study shows that mono- or bicortical plating is not an effective preventive treatment against torsional failure of femora with distal defects as the resulting maximum torque was drastically reduced compared to intact femora. Thus, the initial hypotheses have to be rejected. As habitual loading of the femur includes a combination of axial and torsional loading, the observed lack of prevention against torsional failure might help to explain the occurrence of fractures despite plating. Future research towards ameliorating clinical outcome should address the role of defect filling with bone cement or bone grafts regarding the improvement of torsional stability after primary bone tumor treatment in the femur.

Desmoplastic Fibroblastoma (Collagenous Fibroma) of the Knee: A Case Report and Literature Review.

Desmoplastic fibroblastoma, also known as collagenous fibroma, is a rare benign mesenchymal neoplasm that primarily arises in the subcutaneous tissue of upper extremities and limb girdles. The knee is an uncommon location for desmoplastic fibroblastoma. Recent studies have demonstrated the presence of immunoreactivity for FOS like 1 (FOSL1) and rearrangements of FOSL1. A 70-year-old woman presented with a 1-year history of a palpable mass in the medial aspect of the right knee. Physical examination revealed a 4-cm, elastic hard, mobile, nontender mass. Magnetic resonance imaging (MRI) showed a well-defined mass with prominent low signal intensity on all pulse sequences. Contrast-enhanced MRI demonstrated mild internal enhancement with rim enhancement. After an open biopsy, the lesion was successfully treated by complete excision. Histologically, the tumor was composed of bland spindle or stellate-shaped cells embedded in an abundant collagenous stroma. Immunohistochemically, the tumor cells showed diffuse nuclear positivity for FOSL1. These findings were consistent with a diagnosis of desmoplastic fibroblastoma. The patient was asymptomatic and there was no evidence of local recurrence eight months after surgery. Desmoplastic fibroblastoma is a distinctive benign soft-tissue tumor with FOSL1 immunoreactivity and should be clearly distinguished from more biologically aggressive mesenchymal neoplasms.

TGF-β superfamily-induced transcriptional activation pathways establish the RAD52-dependent ALT machinery during malignant transformation of MPNSTs

To study telomere maintenance mechanism (TMM) activation during malignant transformation, we compared neurofibroma (NF) and malignant peripheral nerve sheath tumor (MPNST) in the same patient with type-1 neurofibromatosis (NF1), a total of 20 NF-MPNST pairs in 20 NF1 patients. These comparisons minimized genetic bias and contrasted only changes associated with malignant transformation, while subtracting changes that developed upon the transformation of normal cells to the benign tumor. TGF-β superfamily genes were found to activate the PAX and SOX transcription factors, leading to TMM activation. BMPER activates PAX6 through BMP2 and PAX7 through BMP4; BMP15 activates SOX14; and INHBC activates PAX9 and SOX14. The activated PAX and SOX genes sequentially establish the core architecture of the RAD52-dependent alternative lengthening of telomeres (ALT). Specifically, PAX7 activates the recombinase (RAD52) and a negative regulator (SLX4IP). PAX6 and SOX14 activate positive regulators (BLM and BRCA2, respectively). PAX9 and SOX14 activate RAD9B and FEN1, which are responsible for the stability of homologous recombination intermediates and increase, together with RAD52, the telomere length. Telomere elongation achieved by the activation of PAX7 and PAX9 is associated with a poor prognosis. We demonstrated that TGF-β superfamily-induced transcriptional activation pathways activated the RAD52-dependent ALT during malignant transformation of MPNSTs.