Soft Tissue Mass Research Articles

Synovial myxosarcoma in the scapulohumeral joint of a dog: a case report.

A 12-year-old, 3kg spayed female mixed-breed dog was evaluated to assess a 1-year history of intermittent right forelimb lameness that did not have adequate response to nonsteroidal anti-inflammatory drugs. The radiographic study performed under sedation showed multifocal radiolucent areas affecting both the right humerus and scapula with focal soft tissue swelling; a CT scan confirmed the existence of an aggressive and invasive soft tissue mass affecting the scapulohumeral joint. Fine needle aspiration results suggested a low-grade synovial sarcoma and therefore a scapulectomy was performed. The biopsy showed spindle to stellated cells immersed in a basophilic and mucinous (myxoid) matrix with mild to moderate anisocytosis, moderate anisokaryosis, some binucleated cells and sporadic multinucleated cells. These findings are consistent with low-grade synovial myxosarcoma, a not well described synovial neoplasm that can mimic other commonly seen joint tumors or even septic arthritis on radiographs. The purpose of this case report is to describe the first reported synovial myxosarcoma affecting the scapulohumeral joint of a small dog.

Development and validation of reference equations for dual-energy X-ray absorptiometry-derived measures of fat-free mass in adults aged 45-85 years: results from the Canadian Longitudinal Study on Aging.

Reference equations for fat-free mass (FFM) and lean soft tissue mass (LM) measures obtained from dual-energy X-ray absorptiometry (DEXA) are important for the interpretation of body composition. This study developed and validated reference equations for FFM and LM using DEXA from the Canadian Longitudinal Study on Aging. Reference equations were developed using data from a random population-based sample of ostensibly healthy and functionally independent adults aged 45-85 years. Reference equations for absolute (accounting for age, sex, height, and body mass) and height-adjusted aka index (accounting for age, sex, and body mass index) measures of FFM and LM were developed using quantile regression. Reference equations were respectively developed and validated in derivation (80%) and validation cohorts (20%). Reference equations were applied to symptomatic adults with self-reported chronic obstructive pulmonary disease (COPD) or heart disease to assess discriminant validity; and compared with other published equations to assess performance. Bland-Altman analyses and Lin's concordance correlation coefficients were utilised to assess agreement. Reference equations for 5th, 10th, 50th, 90th, and 95th percentiles were developed for DEXA-derived estimates of FFM and LM based on 1881 healthy participants (57% male) aged 55 [IQR: 50-61] years. Reference equations performed comparably in the validation cohort and discriminated reference values between ostensibly healthy adults and people with symptomatic COPD or heart disease. Previously published reference equations tended to over- or under-predict estimates of LM compared with the current reference equations. This study provides a comprehensive and validated set of reference equations for estimating and interpreting FFM and LM from DEXA in Canadian adults aged 45-85 years, although additional validation may be required for those>75 years.

MRI of Soft-Tissue Tumors: What to Include in the Report.

MRI serves as a critical step in the workup, local staging, and treatment planning of extremity soft-tissue masses. For the radiologist to meaningfully contribute to the management of soft-tissue masses, they need to provide a detailed list of descriptors of the lesion outlined in an organized report. While it is occasionally possible to use MRI to provide a diagnosis for patients with a mass, it is more often used to help with determining the differential diagnosis and planning of biopsies, surgery, radiation treatment, and chemotherapy (when provided). Each descriptor on the list outlined in this article is specifically aimed to assist in one or more facets of the overall approach to soft-tissue masses. This applies to all masses, but in particular sarcomas. Those descriptors are useful to help narrow the differential diagnosis and ensure concordance with a pathologic diagnosis and its accompanying grade assignment of soft-tissue sarcomas. These include a lesion's borders and shape, signal characteristics, and contrast enhancement pattern; the presence of peritumoral edema and peritumoral enhancement; and the presence of lymph nodes. The items most helpful in assisting surgical planning include a lesion's anatomic location, site of origin, size, location relative to a landmark, relationship to adjacent structures, and vascularity including feeding and draining vessels. The authors provide some background information on soft-tissue sarcomas, including their diagnosis and treatment, for the general radiologist and as a refresher for radiologists who are more experienced in tumor imaging. ©RSNA, 2024 See the invited commentary by Murphey in this issue.

Trends in the use of immunotherapy to treat soft tissue sarcoma

BackgroundThe role of immune-oncology (IO) therapy in soft tissue sarcoma (STS) is underexplored. This study characterized IO use in STS. MethodsThis is a retrospective analysis of patients with a soft tissue mass in the National Cancer Database, 2011–2021. Patients were categorized by IO receipt status. Groupwise testing and proportional trend tests were performed with Chi-squared tests. Multivariate logistic regression was performed to assess factors associated with IO receipt. ResultsOf the 103,092 patients with STS, 1935 (1.9 ​%) received or were recommended IO therapy. IO use increased 10-fold (0.24 ​%–2.5 ​% from 2011 to 2021; p ​< ​0.0001). Patients had higher odds of receiving IO when having higher grade tumors and metastatic disease, and when treated at an academic research center (all p ​< ​0.001). ConclusionsIO use in STS is low but increasing and primarily used in the metastatic setting. Future studies should identify biomarkers of IO response and facilitators for treatment receipt.

Periosteal osteosarcoma: A study of demographic and socioeconomic factors.

e23506 Background: Periosteal Osteosarcoma (PO) is a rare primary malignant bone cancer that typically affects the tibia or femur of young adults in their second and third decades of life. This soft-tissue mass causes extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into soft-tissue components. Despite the rarity of PO, 29% of diagnosed patients do not survive past 10 years following treatment. Further investigation into the diagnostic trends of PO may produce valuable information about its epidemiology. The National Cancer Database (NCDB) was analyzed to identify the demographic factors of patients diagnosed with PO. Methods: A retrospective cohort analysis that utilized data from the 2004–2020 NCDB included 138 patients with a histologically-confirmed diagnosis of PO (ICD-9193-3). Demographic factors (age, sex, race, Hispanic status, educational attainment, insurance status, facility type, distance from facility, and Charlson/Deyo score were analyzed by descriptive statistics, and incidence trends were interpreted via regression analysis. Results: A total of 138 individuals had a confirmed diagnosis of PO between the years 2004-2020 with a relatively constant rate of diagnosis each year (R2 = 0.1749). The average age of diagnosis was 29.7 (SD = 17.5, range = 6-86 years). Males and females were affected at rates of 58% and 42%, respectively. The majority of patients diagnosed with PO identified as White (73%) and non-Spanish/non-Hispanic (86%). The primary sites of diagnosis were the long bones of the lower limb (77%), with an average tumor size of 94.4 mm (SD = 54.2). Most patients (73%) utilized surgical treatment options such as radical excision or resection of the lesion with limb salvage. A higher percentage of patients were privately insured (62%), lived in a metropolitan area (75%), and were treated at an academic/research program (59%). Many individuals (91%) had no concurrent comorbidities (Charlson-Deyo comorbidity score = 0). Following treatment, the survival rates of patients were 91% at 2 years, 78% at 5 years, and 71% at 10 years. Conclusions: To our knowledge, this is the first NCDB analysis concentrating on PO, addressing a substantial gap in our understanding. In congruence with earlier descriptions of PO in case reports, a majority of patients are White and of non-Spanish/non-Hispanic origin and the primary site of diagnosis presents on the lower limbs. This is the first instance in the literature where the socioeconomic factors of PO patients have been clarified: PO patients are more likely to live in densely populated metropolitan areas, receive treatment in academic programs, and have private insurance. Further research is needed to elucidate the influence of demographic and socioeconomic factors on the diagnosis, treatment approaches, and survival outcomes of individuals with PO.

Structured Reporting of Superficial Soft Tissue Masses on Ultrasonography: A Closed-Loop Clinical Audit From a Tertiary Care Hospital in Pakistan.

Background Among all the modalities of diagnostic radiology, ultrasonography is considered the least invasive one. However, this benefit usually comes at the cost of its subjective evaluation since it is purely a dynamic diagnostic modality. Thus, instead of ultrasonography, most clinicians usually rely on the report written by the radiologist. Objective The objective of this study is to evaluate the clinical practices of ultrasound reporting of superficial soft tissue masses. Materials and methods A closed-loop retrospective and prospective study was conducted at the Department of Radiology and Medical Imaging, Jinnah Hospital, Lahore between December 2023 and March 2024. In the pre-intervention phase, a randomly collected sample of 100 ultrasound reports documenting superficial soft tissue masses were included in the study and judged against standard criteria set bythe Royal College of Radiologists (RCR). The intervention phase included regular presentations, identification of problems, and designing of preformed reporting forms. Post-intervention assessments were based on the judgment of 100 ultrasound reports in each cycle twice.Intervention and post-intervention assessments were done twice to correct the ongoing practices. Results During the pre-intervention phase, the ultrasound reports issued by thedepartment of study showed only 41.5% compliance with the RCRstructured reporting guidelines. However, after the first and second post-intervention phases, this percentage increased up to 98.3%. Overall, we observed a compliance difference of 56.5% between the pre-intervention and second post-intervention phases. Conclusion Integration of methods, such as briefing the residents on RCR guidelines, displaying parameters, and making structured report templates available, can greatly increase adherence to RCR guidelines for structured ultrasonography reporting. It also greatly enhances the comprehensiveness and reliability of ultrasonography reports for clinicians. Clinical audits should be routinely practiced in the settings of radiology.

A rare cause of malignant otitis externa and skull base osteomyelitis.

An elderly male with type 2 diabetes presented with a 2-month history of otalgia and severe headaches. He was diagnosed with malignant otitis externa (MOE) and was commenced on empirical treatment with oral ciprofloxacin. Pseudomonas is the most common cause of MOE. A baseline CT scan was undertaken that demonstrated skull base osteomyelitis (SBO) due to findings of bone erosion at the mastoid tip and an infiltrating soft tissue mass eroding the clivus. Eight weeks later, he returned with worsening and bilateral symptoms of otitis externa, hearing loss, temporomandibular pain and dysfunction. Worsening and now bilateral malignant otitis externa were confirmed with an MRI scan that also demonstrated a small fluid collection in his left temporal region. The collection was aspirated and grew scedosporium apiospermum. He was diagnosed with fungal SBO and was commenced on treatment with the antifungal voriconazole, with significant improvement in symptoms and radiological findings. Fungal osteomyelitis is more likely in immunosuppressed patients, particularly those with type 2 diabetes. Fungal aetiology should be suspected in patients with progressive symptoms, despite treatment. A microbiology diagnosis of fungal SBO or MOE can be challenging to obtain and can lead to diagnostic delay. A sampling of the external auditory canal can aid in diagnosing MOE; however, scedosporium may also be isolated as a commensal organism. Aspirations from accessible fluid collections, infratemporal fossa needle sample and bone biopsy can provide material for diagnosis. Scedosporium is a rare cause of disease in humans, however, fungal infections are increasing in humans, due to an increase in susceptible populations. Scedosporium apiospermum is a rare cause of SBO and should be considered in patients not responding to standard treatment.

#2538 Asymptomatic perirenal lymphoma: an unusual presentation of primary lymphoma

Abstract Background and Aims Isolated perinephric lymphoma is uncommon clinicopathological entity, reported in less than 10% of cases. Although this is rare finding, every perirenal mass require prompt diagnosis and multidisciplinary approach if needed. Method We described a case of a asymptomatic young woman who presented with accidental ultrasound finding of a „kidney sweat sign“. Results A 40 year old woman was reported to nephrologist after ultrasonography incidentally revealed a „kidney sweat sign“. The patient had normal kidney function and was symptom-free. Also, all laboratory findings were within the reference range. She was admitted to the nephrology department and CT urography, followed by the ultrasound guided coarse needle biopsy was performed. CT scan revealed right perirenal area completely filled with soft tissue mass that was making an external compression of the right kidney with no infiltration of renal tissue, while pathohistology examination of the biopsy core showed non Hodgkin B cell lymphoma of marginal zone. Immunohistochemistry study demonstrated CD20+, CD3-,CD5-, bcl 2+, bcl 6-, CD10-, CD21-, CD23-, CD38+, cyclin D1-, Ki67+ in 5–10 tumor cells. The patient was reported to hematologist where she underwent bone marrow biopsy which did not show evidence of lymphoma involvement. She was initiated on chemotherapeutic treatment R- COP (Rituximab, cyclophosphamide, vincristine and prednisone). Until now she received three doses of immunochemotherapy and showed good response to the therapy with decrease in the mass dimensions at the repeated CT scan without signs of disease dissemination. Conclusion This case report highlights the importance of an urgent and expeditious work up, including both CT scan and biopsy. Multidisciplinary approach in order to get timely diagnosis and treatment are imperative to achieve improved outcomes.

Neoplastic and Non-neoplastic Soft Tissue Lesions Around the Knee.

Neoplastic and non-neoplastic soft tissue masses around the knee are often incidental findings. Most of these lesions are benign with typical imaging characteristics that allow a confident diagnosis. However, some of these incidental neoplastic masses are characterized by morbidity and potential mortality. This review highlights the typical aspects of these lesions, facilitating a correct diagnosis.

Ultrasound of palpable lesions: a pictorial review.

Ultrasound (US) is the imaging modality of choice for evaluation of superficial palpable lesions. A large proportion of these lesions have characteristic sonographic appearance and can be confidently diagnosed with US without the need for biopsy or other intervention. The Society of Radiologists in Ultrasound (SRU) recently published a Consensus Conference Statement on superficial soft tissue masses. The goal of this manuscript is (a) to serve as a sonographic pictorial review for palpable lesions based on the SRU statement, (b) present the typical sonographic features of palpable lesions that can be confidently diagnosed with US, and (c) provide an overview of other palpable lesions with a framework to interpret the US studies and advise on appropriate further management.

Abstract A018: A case of Buschke-Löwenstein tumor with superimposed infection and associated urothelial carcinoma

Abstract The Giant Condyloma Acuminata (GCA), the Buschke-Löwenstein tumor, is a rare and challenging pathology with a less than 0.1% prevalence. This disease is often considered a transitional phase between condyloma acuminatum and squamous cell carcinoma, potentially representing a variant of verrucous carcinoma. Despite its initially benign histological presentation, GCA can evolve into expansive papillomatous proliferations that deeply invade underlying tissues. Studies indicate that GCA may transform into invasive squamous cell carcinoma in 8.5-23.8% of cases. The strong correlation between GCA and human papillomavirus (HPV) infections, particularly subtypes 6 and 11, underscores the role of viral factors in developing this condition. The presented case involves a 57-year-old male with pre-existing medical conditions, including hypertension and diabetes mellitus, who sought emergency care due to escalating suprapubic and penile discomfort. A biopsy of the genital warts identified condyloma acuminatum with an overlying bacterial infection of Proteus mirabilis. Concurrently, pathology identified anogenital squamous cell carcinoma. Notably, the patient had no associated sexually transmitted infections and no prior immunocompromised status. Imaging studies revealed a multilobulated soft tissue mass in the pelvis with prostatic invasion and enlarged lymph nodes. Further investigations, including a transurethral resection of bladder tumor (TURBT), revealed multiple tumor deposits in the bladder, penile lesion, and suprapubic papule. Pathological examinations indicated non-invasive and invasive papillary urothelial carcinoma as well as invasive squamous cell carcinoma in different locations. The tumor was staged as pathologic IIIB T2N3M0, and a collaborative decision between Urology and Oncology teams led to the initiation of neoadjuvant chemotherapy with TIP (cisplatin, ifosfamide, and paclitaxel). The patient underwent the initial chemotherapy cycle with subsequent cycles scheduled every three weeks. Management options for GCA include radiotherapy, cryosurgery, CO2 laser surgery, systemic chemotherapy, and radical surgical excision. While radiotherapy has shown successful outcomes, concerns about anaplastic transformations and post-treatment condylomas make its utilization contentious. The absence of unequivocal guidelines for radiotherapy dosage and fractionation has led to considerations of alternative modalities, but the primary approach remains radical surgical excision. The risk of recurrence remains high due to potential tumor cell spillage during surgery. In conclusion, this case report highlights an advanced manifestation of the Buschke-Löwenstein tumor coexisting with multiple HPV infections. The complexity of GCA and the lack of consensus on optimal therapeutic strategies emphasize the need for timely diagnosis and intervention to ensure favorable prognoses. Various treatment paradigms exist in medical literature, but their efficacy varies, reflecting the ongoing challenges in managing this rare and clinically intricate condition. Citation Format: Aliya M. Khan, Sophia Navajas, Mehmet Hepgur, Samuel A. Kareff. A case of Buschke-Löwenstein tumor with superimposed infection and associated urothelial carcinoma [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr A018.

Schwannoma of Ansa-Cervicalis: A Rare Location for Schwannoma.

Schwannomas are rare neoplasms that originate from the nervous system. We describe a case of schwannoma of the ansa-cervicalis in a patient where preoperative imaging is suggestive of glomus caroticum tumor. A 44-year-old man presented to the surgical oncology department with a recurrent anterior triangle neck swelling. Magnatic resonance ımaging (MRI) demonstrated right enhancing soft tissue mass at the carotid bifurcation consistent with glomus tumor. Intraoperatively, the lesion was found abuting the bifurcatuion and arising from the right ansa-cervicalis. Histopathology evaluation revealed schwannoma. Schwannoma of the ansa-cervicalis is extremely rare. Very few cases have been reported in the literature. Making the preoperative diagnosis is difficult. Preoperative imaging is necessary to rule out other causes of neck masses such as thyroid lesions, lymphadenopathy, and carotid body tumor. Verocay bodies were noted on histology. Schwannoma of cervical region can have origin from any nerve. Any Neurologic post-operative deficit depends on the nerve of origin and the precision of the surgery performed.

Breast Carcinoma with Isolated Orbital Metastasis –A Rare Clinical Entity

Breast cancer with isolated orbital metastasis is a rare clinical entity.We hereby present a rare case report of 35 year old premenopausal lady with known case of carcinoma breast right side (operated for right modified radical mastectomy in year 2017 with final histopathology of pT2N2M0, hormone receptor-positive and Her2-negative disease). She completed adjuvant 8 cycles of standard dose chemotherapy with 4 cycles of Cyclophosphamide, Adriamycin followed by 4 cycles of Paclitaxel followed by local Radiation therapy. She was initiated Tab. Tamoxifen 20 mg once daily and was continued same for 4 years when in July 2021, she complained of sudden decreased visual acuity and diplopia of right eye lasting from last 1 month. Ophthalmological examination confirmed the findings with decreased visual acuity of 6/36 of right eye while visual acuity of left eye was normal. CT scan of orbits revealed 28 × 18mm heterogeneous enhancing soft tissue mass in right orbital compartment,extrabulbar, occupying postero-superior quadrant inseparable from lateral rectus muscle with optic nerve effacement. PET-CT scan was performed which revealed no metastasis elsewhere in the body. She was offered surgical oophorectomy followed by switch to another hormonal therapy of aromatase inhibitors. She showed complete response to treatment and is now disease from last 2 years.

Giant Cell Tumor within the Tibialis Anterior Tendon: A Case Report

Giant cell tumors of tendon sheath (GCT-TS) also characterized as giant cell tumors of low malignant potential (GCT-TSLMP) are extremely rare entities found most frequently in the extremities. It appears as an enlarging painless mass and has a synovial origin. GCT-TS is approximately 1.6% of all soft tissue tumors.1 The GCT-TS of the tibialis anterior tendon is very rare, and recurrence has not been reported in the literature. The authors present a rare case of a 71-year-old male with a GCT-TS within the Anterior Tibialis tendon. The soft tissue mass is characterized by a mix of giant cell reaction &amp; gouty tophus occurring within the Tibialis Anterior Tendon

Changes in Bone Mineral Density in Patients With Non-dialysis-Dependent Chronic Kidney Disease Are Associated With Body Composition

Chronic kidney disease (CKD) and low bone mineral density (BMD) are highly prevalent and can co-exist. Parameters of mineral metabolism are associated with BMD in CKD, but other contributing factors may contribute. The aim of this study was to assess changes in BMD and its determinants in patients with non-dialysis-dependent CKD (NDD-CKD). Body composition and biochemical profiles were assessed in a retrospective hospital-based cohort study of patients with NDD-CKD. BMD, lean soft tissue (LST), appendicular LST (ALST), and percentage fat mass were assessed by dual-energy X-ray absorptiometry (DXA). ALST index (ALSTI, ALST/height2) and load-capacity index (LCI, fat mass/LST) were calculated. Low BMD was defined as t-score ≤-1.0. Mean time between assessments was 2.8±1.3 years, 46 patients were included. A reduction in renal function was observed. Changes in body composition included reductions in ALST (p=0.031), ALSTI (p=0.021) and a trend for BMD (p=0.053); and an increase in percentage fat mass (p=0.044) and LCI (p=0.032). Females had a reduction in BMD (p=0.034), ALST (p=0.026), and ALSTI (p=0.037). Patients with low BMD at baseline had lower LST (p=0.013), ALST (p=0.023), and percentage fat mass (p=0.037) than those with normal BMD. Additionally, reductions in LST (p=0.041), ALST (p=0.006), and ALSTI (p=0.008) were observed in patients who had low BMD at baseline, while no significant changes in body composition were observed in those with normal BMD at baseline. The following body composition parameters at baseline were determinants of BMD status at follow-up: LST (OR:0.899, 95%CI:0.829-0.976, p=0.010), ALST (OR:0.825, 95%CI:0.704-0.967, p=0.017), and ALSTI (OR:0.586, 95%CI:0.354-0.968, p=0.037), independent of fat mass, and LCI. Detrimental body composition changes were observed without changes in body weight; these were more significant in females. Moreover, this is the first longitudinal study showing a protective effect of LST against BMD loss in patients with NDD-CKD.

Evaluation of the anterior processes of the parotid gland: an ultrasonographic study.

This study aimed to determine the prevalence of anterior extensions of the parotid gland (AEPG), namely the accessory parotid gland (APG) and the facial process of the parotid gland (FP), using ultrasonography. A total of 338 parotid glands were scanned bilaterally. APG was defined as a soft tissue mass with the same echogenic features as the main parotid gland (MPG) and not in contact with it, while FP was defined as an extension that exceeded the anterior border of the mandibular ramus and was continuous with the MPG. The anteroposterior, mediolateral, superoinferior dimensions and the mean distance from the MPG to the APG were measured. The prevalence of APG and FP were 19.5% and 36%, respectively, resulting in an AEPG prevalence of 55.6%. The presence of APG was statistically higher in females than in males (p = 0.039). The mean anteroposterior, mediolateral, and superoinferior dimensions of the APG were 18.1 ± 0.57mm, 0.35 ± 0.17mm, and 12.3 ± 0.36mm, respectively, and the mean distance from the MPG was measured as 12.1 ± 0.87mm. This study can raise awareness among clinicians about the presence of AEPG in the differential diagnosis of mid-cheek masses.

Abstract PO4-22-06: Outcomes following Stereotactic Radiotherapy in Oligometastatic Breast Cancer: a single centre retrospective review

Abstract Introduction: Stereotactic radiotherapy (SABR) is an increasingly used treatment for oligometastatic disease with evidence of survival benefit shown in the SABR-COMET trial. However, the benefit in oligometastatic breast cancer has been brought into question following initial results from the NRG-BR002 trial. Methods: A retrospective review of all patients with primary breast cancer treated with stereotactic radiotherapy for oligometastases at our institution was carried out. A total of 31 patients received treatment to 36 lesions between August 2015 and December 2022. Results: Neither median overall survival nor progression free survival were reached after median follow up time of 21.5 months. Hormone receptor status as follows: ER+, HER2- (n=25), ER+, HER2+ (n=4,), TNBC (n=2). The majority of lesions treated were bony metastases (92%, of which 17 vertebral and 11 pelvic lesions). The majority had oligometastatic disease at time of SABR (67%), with 33% treated for oligoprogression. Most patients were on systemic anti-cancer therapy (SACT) at the time of SABR, or had a planned start of SACT shortly following treatment. Breakdown of systemic therapy as follows: Endocrine therapy (ET) alone 9 patients (29%), CDK4/6 inhibitor plus ET 13 patients (42%), chemotherapy 3 patients (10%), antibody drug conjugate 2 (6%), anti-HER2 therapy + ET 2 patients (6%), none 2 patients (6%). All patients also received bone-targeted agents (zoledronic acid or denosumab). Local control was achieved in 33 lesions (92%), all of which were bony lesions. Local control was maintained in both patients who were not on SACT: one patient with ER+ HER2- disease developed distant progression after 27 months, the other with TNBC remains disease free after 13 months. Loss of local control was observed in all non-bony sites (lung, IMC node, peri-ureteric soft tissue mass) at a median interval of 10 months (range 7-43 months). 14 patients subsequently developed distant disease progression at median interval of 15 months (range 0-43 months). 12 month progression free survival was 77%. 13 patients received further SACT at median interval of 16 months. Conclusions: SABR for bony metastases from breast cancer has excellent local control rates in combination with systemic treatment but may also give patients significant time off treatment. Questions remain regarding the ideal sequencing and combination of SABR and SACT, particularly in hormone receptor positive patients where there are a number of lines of effective SACT. Citation Format: Sophie Lynch, Sugeeta Sukumar, Elinor Sawyer, Daniel Smith, Christy Goldsmith. Outcomes following Stereotactic Radiotherapy in Oligometastatic Breast Cancer: a single centre retrospective review [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-22-06.

Transurethral Resection of Necrotic Tissue in the Bladder Caused by Emphysematous Cystitis

Emphysematous cystitis is a relatively rare form of urinary tract infection. A 72-year-old man with diabetes mellitus and long-term indwelling urethral catheterization was diagnosed with emphysematous cystitis. The clinical findings were resolved by conservatively managing the patient with antibiotics. However, cystoscopy subsequently revealed a yellowish-white soft tissue mass in the bladder, which was unlikely to be a bladder tumor. The mass could not be removed easily and frequently caused urinary catheter obstruction. We successfully removed this mass by performing transurethral resection twice. Through histopathological examination, the mass was identified as necrotic tissue comprising bacteria, fibrin, and suspected bladder mucosa.

Findings of an Extraluminal Leiomyosarcoma of the Urinary Bladder in a Dog.

A 9 yr old male miniature poodle presented with acute diarrhea, vomiting, and a distended abdomen. A large and firm mass was palpated in the caudal abdomen. Radiography showed a large soft-tissue mass in the mid ventral abdomen. The mass was mildly contrast-enhancing and in contact with the right cranial aspect of the bladder on computed tomography. The mass was heterogeneous with minimal blood flow on Doppler examination. Surgery confirmed its origin of the urinary bladder, and it was diagnosed leiomyosarcoma on pathology. This is the first report of extraluminal leiomyosarcoma of the bladder wall with imaging characteristics using various modalities.

Scar endometriosis as an easily misdiagnosed abdominal mass: a case report and review of the literature

Scar endometriosis, which is characterized by ectopic endometrial-like glands and stroma surrounding scar tissue, is rare and presents diagnostic challenges due to its inconsistent presentation. We report a case of a 40-year-old woman who had previously undergone two cesarean sections and a hysterectomy, in whom a mass in the subcutaneous layer of the lower abdomen was incidentally discovered by computed tomography (CT). A physical examination revealed a linear cesarean scar with a palpable, pigmented mass. An enhanced abdominal CT scan revealed an approximately 3.5-cm ill-defined soft tissue mass infiltrating the rectus abdominis muscle. A desmoid tumor was suspected based on the radiological findings, and endometriosis was also considered in light of the patient’s medical history. Wide mass excision was performed, ensuring 5-mm margins. The mass was completely excised, and a histopathological examination revealed endometriosis. Due to its rarity, scar endometriosis in the abdominal area can be easily misdiagnosed. Therefore, a heightened suspicion of scar endometriosis should be maintained in female patients with a history of abdominal or pelvic surgery presenting with an abdominal mass. Although imaging modalities can play a supportive role in the diagnosis, an extensive medical history assessment and comprehensive physical examination remain crucial.