Malignant Transformation of Plexiform Neurofibroma Due to Neglected Giant Soft Tissue Swelling of the Back: A Case Report.

Neurofibromatosis type 1 can be severe and associated with malignant transformation. Proper follow-up and monitoring are very important in preventing the malignant transformation of neurofibromatosis. We encountered a case of malignant transformation of plexiform neurofibroma into neurofibrosarcoma (also known as malignant peripheral nerve sheath tumor). She had been presenting with a large mass on her back for a few years, which was also associated with an ulcer. She underwent a wide-excision biopsy of her back, and the histopathology examination (HPE) came back with a malignant peripheral nerve sheath tumor. This case concludes that any patient with a known case of neurofibromatosis should undergo follow-up to detect any malignant transformation of the disease. Early detection of the malignant transformation of neurofibromatosis can help prevent the disease's progression. The main treatment is surgical resection; however, the risk of local recurrence is higher, especially in patients with neurofibromatosis type 1.

Synovial Sarcoma of the Kidney: Diagnostic Pitfalls in a Case with Myxoid Monophasic Differentiation and No Epithelial Biomarkers Expression.

Synovial sarcomas are soft tissue tumours of uncertain origin, most commonly found in the upper or lower extremities. They are characterised by distinctive chromosomal rearrangements involving the gene SS18. Synovial sarcomas can occasionally arise also in visceral sites, but retroperitoneal SSs are very unusual. Among them, a few primary renal synovial sarcomas have been described in the scientific literature. Primary renal synovial sarcomas tend to be monophasic and often show cystic changes. Histologically, they can closely resemble other primary kidney tumours, mainly paediatric tumours such as nephroblastoma and clear cell sarcoma of the kidney. In the current work, a primary synovial sarcoma of the kidney with unusual morphological features (extensively myxoid stroma and immunohistochemical positivity for BCOR) is described. Molecular analysis, through targeted RNA sequencing, was of invaluable help in reaching the correct diagnosis. Despite locally advanced disease at presentation, the patient showed an unexpectedly brilliant response to chemotherapy.

Myofibrosarcoma of Maxilla - Case Report and Review of Literature.

Myofibrosarcoma is a distinct mesenchymal malignancy which commonly occurs in head and neck region. It has a high tendency for local recurrence and distant metastasis. 39-year-old male presented with epistaxis, nasal obstruction and left sided complete loss of vision. He underwent functional endoscopic sinus surgery and guided biopsy. MRI scan showed a lesion epicentred in the left maxillary sinus, superiorly extending into the orbit. He underwent Class 4b maxillectomy with neck dissection, tracheostomy and free flap reconstruction. Histopathological examination yielded final diagnosis as myofibrosarcoma of maxilla. The patient was planned for adjuvant radiotherapy and has been disease free for 3 years.

Recurrent and novel fusions detected by targeted RNA sequencing as part of the diagnostic workflow of soft tissue and bone tumours.

The identification of gene fusions has become an integral part of soft tissue and bone tumour diagnosis. We investigated the added value of targeted RNA-based sequencing (targeted RNA-seq, Archer FusionPlex) to our current molecular diagnostic workflow of these tumours, which is based on fluorescence in situ hybridisation (FISH) for the detection of gene fusions using 25 probes. In a series of 131 diagnostic samples targeted RNA-seq identified a gene fusion, BCOR internal tandem duplication or ALK deletion in 47 cases (35.9%). For 74 cases, encompassing 137 FISH analyses, concordance between FISH and targeted RNA-seq was evaluated. A positive or negative FISH result was confirmed by targeted RNA-seq in 27 out of 49 (55.1%) and 81 out of 88 (92.0%) analyses, respectively. While negative concordance was high, targeted RNA-seq identified a canonical gene fusion in seven cases despite a negative FISH result. The 22 discordant FISH-positive analyses showed a lower percentage of rearrangement-positive nuclei (range 15-41%) compared to the concordant FISH-positive analyses (>41% of nuclei in 88.9% of cases). Six FISH analyses (in four cases) were finally considered false positive based on histological and targeted RNA-seq findings. For the EWSR1 FISH probe, we observed a gene-dependent disparity (p = 0.0020), with 8 out of 35 cases showing a discordance between FISH and targeted RNA-seq (22.9%). This study demonstrates an added value of targeted RNA-seq to our current diagnostic workflow of soft tissue and bone tumours in 19 out of 131 cases (14.5%), which we categorised as altered diagnosis (3 cases), added precision (6 cases), or augmented spectrum (10 cases). In the latter subgroup, four novel fusion transcripts were found for which the clinical relevance remains unclear: NAB2::NCOA2, YAP1::NUTM2B, HSPA8::BRAF, and PDE2A::PLAG1. Overall, targeted RNA-seq has proven extremely valuable in the diagnostic workflow of soft tissue and bone tumours.

Surgical Excision of Lipomas in Bilateral Upper Limbs and Right Thigh: A Case Report.

Lipomas are common benign soft tissue tumors composed primarily of mature adipose tissue. They are often encountered clinically due to their characteristic slow growth, typically as soft, painless, subcutaneous nodules. While lipomas are generally asymptomatic, surgical intervention is sought by patients when they lead to discomfort, cosmetic concerns, or functional impairment. In this case report, we present the successful surgical excision of 25 lipomas in the bilateral upper limbs and right thigh of a 43-year-old male. Pre-operative assessment, precise surgical technique, and post-operative care are highlighted as essential management components. The case emphasizes the importance of individualized treatment, ensuring symptomatic lipomas' diagnosis and effective management. This report serves as a valuable reference for healthcare professionals caring for patients with lipomatous lesions, contributing to understanding soft tissue tumor management.

Soft tissue tumours of the penis. The 30-year Istituto Nazionale Tumori di Milano experience.

Objective: Small series and individual cases of penile soft tissue tumours are reported in the literature: these are rare tumours that represent less than 5% of all penile tumours. Methods: Penile soft tissue tumours were collected from the archive of the Department of Pathology at the Istituto Nazionale dei Tumori of Milan between January 1990 and October 2021. All available medical records were retrieved and reviewed to obtain clinical information. Results: Our series refers to the 30-year experience of highlighting the heterogeneity in the presentation and microscopic features of these rare sarcomas. 18 penile soft tissue tumours are described, 4 benign and 14 malignant. The mean age at diagnosis was 58.2 years (range 24-96 years) and 53.6 years among malignancies (range 24-89). The most frequent histotype was Kaposi's sarcoma (nr = 4) and very unusual histotypes were observed, namely low-grade fibromyxoid sarcoma, synovial sarcoma, proximal type epithelioid sarcoma and the first reported case of dedifferentiated liposarcoma of the penis. Conclusions: Among sarcomas of the genitourinary tract, tumours of the soft tissues of the penis are the rarest. Penile sarcomas can present at a young age. Kaposi's sarcoma in HIV-negative patients has a favorable outcome, while deep sarcomas have an aggressive behavior and poor prognosis.

A Rare Case Report of Granular Cell Tumour of the Abdominal Wall and a Review of the Literature.

Granular cell tumours (GCTs) are rare soft tissue tumours of neural origin. They have been reported in multiple anatomical sites. However, only 14 cases worldwide have been reported arising from the abdominal wall. While they can clinically manifest in a variety of ways, often they present as a small, slow-growing nodule with benign features. They can, however, be malignant, and in rare cases, they have been reported to metastasise. Here, we present a case of a rare abdominal wall GCT, which was managed with local excision. The purpose of this paper is to report the patient's clinical history, presentation, and surgical management, as well as to review the current literature to highlight the existence of this rare entity and the possibility that this may occur and should be considered a differential diagnosis in clinical practice.

Superficial CD34-Positive Fibroblastic Tumor: A Case Series and a Review of Literature.

Superficial CD34-positive fibroblastic tumor (SCD34PFBT) is a recently recognized neoplasm of mesenchymal origin. Only a few cases have been reported in the literature so far. Microscopically, it consists of a dermal spindle cell neoplasm, with low mitotic activity, arranged in a fascicular pattern. The individual neoplastic cells show marked nuclear atypia, nuclear pseudo-inclusions, and dense eosinophilic cytoplasm. The tumor cells characteristically show positivity for CD34 immunohistochemical stain. This tumor behaves as a low-grade malignancy with potential to recur locally, with rare cases showing lymph node metastasis. Wide local excision and regular follow-up are the currently followed steps for management. This tumor serves as a diagnostic challenge due to its overt atypia, and it can be misdiagnosed as a sarcoma. Recognition of this entity among pathologists is important due to this reason. We hereby report four cases of this newly recognized entity.

A Rare Case of Paratesticular Leiomyosarcoma.

Paratesticular leiomyosarcoma is a rare urologic cancer that arises from undifferentiated smooth muscles of the spermatic cord or epididymis. Few accounts of this cancer have been reported but previous reports have identified radiation and anabolic steroids as possible risk factors. We report a case of an 83-year-old man with a previous history of radiation therapy for prostate cancer, who presented with a painless left scrotal mass. Given the nonspecific presentation, a histopathological classification was warranted for a definitive diagnosis. The tumor was resected via simple orchiectomy and was diagnosed as a paratesticular grade III leiomyosarcoma without any further treatment. Patient had a follow-up CT scan of the abdomen and pelvis that was normal without metastasis. The patient's history of previous external beam radiation and now development of a secondary tumor sums to the few cases that have been previously reported with this association.

Isolated Elastofibroma of the Thigh: A Case Report.

A 55-year-old female presented with elastofibroma of the thigh. On presentation, she complained of a palpable, painful mass on the anterolateral right thigh that had been present for one year. She had a history of surgery for a right femur fracture. On MRI, a soft-tissue mass was seen in the vastus intermedius muscle, as a heterogeneous lesion with streaky fatty and fibrous components. The fibrous component was isointense to the muscle, and the fatty component had a high signal on both T1- and T2-weighted images. Histopathological analysis after biopsy established the diagnosis of elastofibroma.

Benign tumours of foot and ankle.

Musculoskeletal tumours of foot or ankle make up about 4-5% of all musculoskeletal tumours. Fortunately, about 80% of them are benign. However, due to the rarity and low prevalence of each single tumour entity, diagnosis is often difficult and delayed. Ultrasonography is an important diagnostic tool to safely recognize ganglion cysts as a frequently encountered 'bump' in the foot. In suspicious lesions, malignancy must be excluded histologically in a tumour center by biopsy after imaging procedures using x-ray, computed tomography (CT) and magnetic resonance imaging (MRI). Most of the benign tumours do not require any further surgical therapy. Resection should be performed in the case of locally aggressive tumour growth or local symptoms of discomfort. In contrast to malignant tumours, the primary purpose in the resection is the least possible loss of function.

Malignant adipocytic tumours: A 20­year single­centre retrospective study.

Adipocytic tumours are the most common soft tissue neoplasms. Among them, liposarcoma is the most frequent malignant neoplasm. However, to the best of our knowledge, no previously published study has assessed the evolution and oncological prognosis of the different subtypes of liposarcoma at the retroperitoneal level compared with at other locations. The present study is a retrospective observational study in which all patients were operated on between October 2000 and January 2020 with a histological diagnosis of liposarcoma. Variables, such as age, sex, location, histological type, recurrence, type of treatment and mortality, among others, were analysed. The patients were divided into two groups: Group A (retroperitoneal location) and group B (non-retroperitoneal location). A total of 52 patients with a diagnosis of liposarcoma (17 women and 35 men) and a mean age of 57.2±15.9 years were assessed. A total of 16 patients were classified into group A and 36 into group B. The OR of recurrence was 1.5 (P=0.02) for R1 vs. R0 resection in group A. The OR of recurrence in group B for R1 vs. R0 resection was 1.8 (P=0.77), whereas for R2 vs. R0 resection, the OR was 69 (P=0.011). In conclusion, 52 cases of malignant adipocytic tumours collected during 2000-2020 were analysed with the new World Health Organization classification (updated 2020). Although its recurrence potential and capacity for distant metastasis depended on each histological type, surgical treatment with unaffected margins was the main prognostic factor for survival. The present study identified differences in relation to the survival of each histological subtype and its location, finding greater survival in dedifferentiated liposarcoma, myxoid liposarcoma and pleomorphic liposarcoma located at the extraperitoneal level than in the retroperitoneal location. Resectability was not influenced by liposarcoma location.

Giant Soft Tissue Leiomyosarcoma of the Left Lower Extremity: Case Presentation With a Review of the Literature.

Leiomyosarcoma (LMS) accounts for approximately 5-10% of soft tissue sarcomas, with an estimated incidence in the United States (US) of less than one case/200,000 persons, more frequent in women than men. Approximately two-thirds of LMSs are retroperitoneal, abdominal, and mediastinal. Localized, soft tissue LMSs represent a lower percentage, with the lower limbs and trunk being the most frequently involved sites. LMSs larger than 5 cm (so-called giants) are even rarer, and to date have been little reported in the literature. In this paper, we present the case of a giant LMS of the left lower limb in a 73-year-old patient, who had a mass for about two years, and who, after the first diagnostic biopsy, underwent limb amputation. Macroscopic and microscopic examinations confirmed the infiltration of the underlying tibial bone. We briefly discuss eight other cases described in the literature with similar size, pointing out that the parameters with the greatest impact on prognosis proved to be size >5 cm and depth of invasion. Due to the rarity of this neoplasm, little has yet been done in relation to the most suitable therapeutic treatment of such patients, and larger case series are mandated in order to be able to conduct broader-spectrum studies.

Angiolipoma of the Lower Lip: A Rare Case Report.

Angiolipoma is a benign soft tissue tumor composed of mature adipocytes and small capillaries. Although it can occur in any part of the body, it is rare in the oral cavity, especially in the lips. We report the case of a 47-year-old male who presented with a painless, slow-growing mass on the right lower lip that had gradually increased in size over several months. The initial diagnosis included lipoma, mucocele, and hemangioma. The mass was surgically excised, and the histological examination confirmed the diagnosis of angiolipoma. Angiolipomas involving the lips are rare and can be easily misdiagnosed. Therefore, clinical suspicion, along with appropriate imaging and histological examination, is essential for an accurate diagnosis and appropriate management. The patient had a smooth recovery after surgery and showed no recurrence of the condition during the one-year follow-up examination.

Benign mesenchymal tumours of the tongue: A report of adult-type rhabdomyoma and granular cell tumour with a review of the literature.

The cytomorphological features of benign mesenchymal tumours of the tongue have rarely been reported. Herein, we present the cytomorphological features of adult-type rhabdomyoma, which occurred in the tongue of a female patient, and granular cell tumour (GCT), which occurred in the tongue of a male patient; both patients were in their mid-50s. The cytological features of the adult-type rhabdomyoma case included large polygonal to ovoid cells with abundant and granular cytoplasm with predominantly peripherally located, uniform, round to oval nuclei and small nucleoli. Cross-striation and crystalline intracytoplasmic structures were not seen. The cytological features of the GCT case included large cells with abundant granular pale cytoplasm, small round nuclei and small distinct nucleoli. The cytological differential diagnoses of these tumours overlap; thus, the cytological findings of the different entities included in their differential diagnoses are discussed.

Diagnostic utility of FOXO1 immunohistochemistry for rhabdomyosarcoma classification.

AIMS: Rhabdomyosarcomas currently are classified into one of four subtypes (alveolar, embryonal, spindle cell/sclerosing, or pleomorphic) according to their morphological, immunohistochemical, and molecular genetic features. The alveolar subtype is characterised by a recurrent translocation involving PAX3 or PAX7 and FOXO1; identification of this translocation is important for appropriate classification and prognostication. In this study, we aimed to explore the diagnostic utility of FOXO1 immunohistochemistry for rhabdomyosarcoma classification. METHODS/RESULTS: A monoclonal antibody targeting a FOXO1 epitope retained in the fusion oncoprotein was used to study 105 rhabdomyosarcomas. FOXO1 was positive for expression by immunohistochemistry in all 25 alveolar rhabdomyosarcomas, with 84% showing diffuse expression in greater than 90% of neoplastic cells; the remainder of alveolar rhabdomyosarcomas displayed at least moderate staining in a minimum of 60% of lesional cells. Apart from three spindle cell rhabdomyosarcomas showing heterogeneous nuclear immunoreactivity in 40-80% of tumour cells, the 80 cases of embryonal, pleomorphic, and spindle cell/sclerosing rhabdomyosarcoma were negative for FOXO1 expression (96.3% specific) when using a threshold of nuclear staining in 20% of neoplastic cells to determine positivity. Variable cytoplasmic staining was present in a fraction of all rhabdomyosarcoma subtypes. Nonneoplastic lymphocytes, endothelial cells, and Schwann cells also showed variably intense nuclear anti-FOXO1 immunoreactivity. CONCLUSION: Taken together, our findings suggest that FOXO1 immunohistochemistry is a highly sensitive and relatively specific surrogate marker of the PAX3/7::FOXO1 fusion oncoprotein in rhabdomyosarcoma. Cytoplasmic immunoreactivity, expression in nonneoplastic tissues, and limited nuclear staining of nonalveolar rhabdomyosarcomas represent potential pitfalls in interpretation.

Conjunctival leiomyosarcoma.

Purpose: Leiomyosarcoma (LMS) is a mesenchymal neoplasm with smooth muscle differentiation, being considered one of the most common soft tissue sarcomas. However, it rarely affects the eye, and when it does, it is usually located in the orbit, being extremely rare in the conjunctiva. Observations: We report a case of a 45 years old male patient, with a recurrent rapid growing conjunctival mass on the temporal limbus of his left eye, which was excised, and the anatomopathological report was suggestive of a grade 1 leiomyosarcoma. Since the lesion was recurrent, we decided to perform an extended enucleation for treating this condition. Nevertheless, the patient is being followed up to 30 months, with systemic metastasis screening, showing no other lesions or recurrences. Conclusions and importance: Conjunctival leiomyosarcoma is an extremely rare ocular tumor, which can be clinically indistinguishable from other conditions such as squamous cell carcinoma, so, biopsy is essential. Albeit there is no standard treatment, complete surgical removal with safety margins is mandatory.

Histologic characterization of paediatric mesenchymal neoplasms treated with kinase-targeted therapy.

AIMS: Recurrent alterations involving receptor tyrosine or cytoplasmic kinase genes have been described in soft-tissue neoplasms such as infantile fibrosarcoma (IFS) and inflammatory myofibroblastic tumour (IMT). Recent trials and regulatory approvals for targeted inhibitors against the kinase domains of these oncoproteins have allowed for increased use of targeted therapies. We aimed to characterize the histologic features of paediatric mesenchymal neoplasms with kinase alterations treated with targeted inhibitors. METHODS AND RESULTS: Eight patients with tyrosine kinase-altered mesenchymal neoplasms with pre- and posttreatment samples were identified. Tumours occurred in five females and three males with a median age at presentation of 6.5 years. Tumour sites were bone/somatic soft-tissue (n = 5) and viscera (n = 3). Pretreatment diagnoses were: IMT (n = 3), epithelioid inflammatory myofibroblastic sarcoma (n = 1), and descriptive diagnoses (n = 4) such as "kinase-driven spindle cell tumor." Fusions identified were ETV6::NTRK3 (n = 2), TPM3::NTRK1, SEPT7::BRAF, TFG::ROS1, KLC1::ALK, RANBP2::ALK, and MAP4::RAF1. Patients were treated with larotrectinib (n = 3), ALK or ALK/ROS1 inhibitors (n = 3), and MEK inhibitors (n = 2). Posttreatment tumours exhibited a striking decrease in cellularity (7/8) and the presence of collagenous stroma (7/8) with extensive glassy hyalinization (5/8). In two cases, abundant coarse or psammomatous calcifications were seen and in one case prominent perivascular hyalinization was noted. Residual viable tumour was seen in 3/8 cases (<5% in one case, and >75% in 2/8 cases). CONCLUSION: Mesenchymal neoplasms with tyrosine kinase alterations treated with targeted inhibitors show a pathologic response, which includes decreased cellularity and stromal hyalinization. The presence of these features may be helpful in assessing tumour response after targeted therapy.

Isolated Kimura Disease Presenting as a Brow Mass in a Saudi Male: A Rare Case Report.

This is a case of a 36-year-old male not known to have any medical illness complaining of left upper painless swelling in the eyebrow with no systemic symptoms, and normal physical examination apart from the eyebrow mass. Computed tomography (CT) of the head showed a well-defined hyperdense subcutaneous soft tissue lesion seen at the medial aspect of the left orbit (eyelid-extra orbital). Excisional biopsy of the eyebrow mass was done and sent for histopathological evaluation which reports consistent findings with Kimura disease (KD) as a definitive diagnosis.

Positive Margins Following Excision of Primary Bone & Soft Tissue Tumours in a Tertiary Centre and the Impact on Patient Outcomes.

Background Primary bone and soft tissue sarcoma treatment includes surgical resection, with or without peri-operative chemoradiotherapy. The aim of surgery is to achieve complete excision, to prevent localised recurrence and achieve cure. For various reasons, excision with adequate margins is not always possible. Our aim is to assess the occurrence of unexpected positive margins following primary excision within a tertiary centre and the impact on patient outcomes. Methods A retrospective analysis of 567 patients discussed at the Royal National Orthopaedic Hospital Multi-disciplinary team (MDT) meeting with positive margins between 1999-2020 was performed. Exclusion criteria included: excisions performed externally and lesions treated with curettage. Information gathering from electronic records highlighted 23 cases with unexpected positive margins following primary excision. Results All patients pre-operatively expected to achieve complete primary resection. The median age was 60 years (8-92), 10M:13F. Tumour location included lower limb (12), upper limb (six), pelvis (two) and trunk (three); eight bone tumours and 15 soft tissue. The overall recurrence rate was 30.4% (7/23). In those recommended for re-excision (n=16), the recurrence rate was 31.25% (5/16). Of the patients not initially recommended for re-excision (n=7), four proceeded to surveillance alone with 50% recurrence (2/4), both with metastatic disease not surviving to follow-up. A further three patients underwent post-operative radiotherapy alone with no recurrences at follow-up, one patient not surviving for further treatment due to stroke. The mean follow-up for patients was 3.1 years. Conclusion When positive margins do occur unexpectedly, the impact due to the need for further treatment and ultimately increased risk of recurrence can be significant. Results can be compared to those for unplanned excisions. Therefore, surgeons should be aware of the different circumstances in which positive margins occur to help guide treatment planning and managing patient expectations.