Mediastinal Research Articles

Posterior mediastinal extralobar pulmonary sequestration in a neonate with pulmonary artery supply: a case report

This paper reports a rare case of extralobar pulmonary sequestration in the posterior mediastinum of a neonate with arterial supply from the pulmonary artery. A 3-day-old male neonate was diagnosed with type II congenital pulmonary airway malformation after prenatal color Doppler ultrasonography showed a lesion with blood supply from the pulmonary artery in the left lung. Post-birth chest computed tomography(CT) showed that the lesion was located in the posterior mediastinum with low density change, mild stripe enhancement after contrast, and no obvious blood supply vessels. A neurogenic tumor was considered for the preoperative diagnosis. The mass was removed by video-assisted thoracoscopic surgery. During the surgery, the mass was observed to be a dark red solid lump with a feeding vessel originating from the pulmonary artery. The postoperative histopathological diagnosis was extralobar pulmonary sequestration. Combined with the preoperative imaging results, it was considered that the nourishing vessels might have intermittent torsion. The patient recovered well after surgery, and no recurrence was observed after 6 months of follow-up. Therefore, the possibility of extralobar pulmonary sequestration cannot be ruled out for posterior mediastinal masses that are not supplied by the descending aorta or without identified feeding vessels.

Rare posterior mediastinal hemangiomas invading the spinal cord through the intervertebral foramen and causing acute symptoms: illustrative case.

Hemangioma is a rare vascular tumor characterized by endothelial cell proliferation that primarily occurs in soft tissues. While most cases in the paraspinal posterior mediastinum are clinically indolent, they can also exhibit aggressive growth, leading to severe clinical outcomes and necessitating urgent treatment. A 61-year-old right-handed female presented with reduced lower-extremity mobility that had begun 4 days earlier. An examination revealed that both lower limbs had grade 4 muscle strength. Computed tomography and magnetic resonance imaging revealed a right T1-3 paravertebral dumbbell-shaped soft tissue mass invading the spinal canal, destroying the T2 vertebra, and compressing the spinal cord and nerve roots. Elective surgery was planned, but a rapid muscle strength decline prompted emergency surgery. Postoperative muscle strength improved to grade 4, and at the 3-month follow-up, muscle strength had fully recovered. Postoperative pathological examination revealed that the mediastinal dumbbell-shaped lesion was a hemangioma. While most hemangiomas progress slowly, acute symptoms of spinal cord compression are exceedingly rare. This case demonstrates the aggressive behavior of hemangioma, which invaded through the intervertebral foramen and compressed the spinal cord, resulting in acute symptoms. This case also shows that surgical removal of the tumor and restoration of spine stability via a posterior approach has proven beneficial. https://thejns.org/doi/10.3171/CASE24485.

"Mini Brain" Appearance in Spinal Metastasis From Type A Thymoma Detected by 18F-FDG PET/CT.

A 66-year-old man presented with persistent dull pain in the lower back for over 7 months. An expansile lytic lesion in the L4 vertebral body showed a characteristic "mini brain" appearance on MRI, which is highly suggestive of plasmacytoma. 18F-FDG PET/CT scan revealed increased FDG uptake in the L4 lesion, with an additional finding of a mass in the anterior mediastinum that showed mild FDG uptake. Lumbar surgery and complete resection of the anterior mediastinum tumor confirmed spinal metastatic type A thymoma, which was classified as p-T1aN0M1b, stage IVb. The patient's condition improved postsurgery and chemotherapy, with long-term follow-up necessary due to recurrence risk.

Electrical performance of a novel extravascular temporary pacing lead system

Abstract Background An investigational extravascular (EV) cardiac temporary pacing system has been developed that includes a parasternally-positioned temporary pacing lead within the anterior mediastinum. The pacing lead is inserted using a custom delivery tool through a parasternal skin incision. This novel system may provide clinical advantages over existing device alternatives that require intravascular, endocardial, or epicardial contact. Objective The purpose of this study was to evaluate electrical performance of an EV temporary pacing lead over 48 hours. Methods In this single-center study, patients who underwent a transvenous (TV) permanent pacemaker implant or replacement were simultaneously implanted with the investigational EV temporary pacing lead. Electrical performance was evaluated through analysis of capture thresholds, impedance, and R-wave amplitudes during multiple times on the day of the procedure and on the subsequent 2 days of follow-up. Results Lead insertions with acute capture were successful in all 8 patients (40% female, 71 ± 8 years, BMI 27 ± 3 kg/m2). Mean acute measurements for pacing capture threshold at 1.5 ms, impedance and R-wave amplitude were 6.2 mA, 1396 Ω, 5.4 mV, respectively. Pacing capture was maintained in 100% of assessments conducted over 3 days (Figure 1). There were no serious complications during insertion, removal or chronic use of the lead. Conclusions Results support that the investigational EV temporary pacing lead is capable of safely providing temporary pacing with thresholds typically well below the maximum output of temporary pacemakers.

Exploring the complexity, treatment challenges, and outcomes in pediatric nodular lymphocyte predominant Hodgkin lymphoma: a perspective from a low–middle-income country

BackgroundIn children, nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is an uncommon subtype of Hodgkin lymphoma. Given the lack of data on the best chemotherapy regimen, there is a knowledge gap in best management.MethodsThis retrospective study included all pediatric patients with NLPHL diagnosed and treated at the Children’s Cancer Hospital, Egypt (2007–2018). We analyzed the clinical characteristics, and treatment outcome according to disease stage (early and advanced), treatment strategy (doxorubicin, bleomycin, vinblastine, and dacarbazine [ABVD] or rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone [R-CHOP] and explored the prognostic factors for progression-free survival.ResultsThe median age at diagnosis was 12 years; 40 (68%) patients had early-stage disease, and 19 (32%) had advanced-stage disease. The median follow-up was 70 months; the 5-year EFS and OS were 75% and 97%, respectively. The 5-year EFS was 78% for early-stage disease and 60% for advanced-stage disease; the 5-year OS was 100% for early-stage disease and 88% for advanced-stage disease. The patients who underwent R-CHOP had a better 3-year EFS (100%) compared with those who underwent ABVD (65%) regimen (P = 0.01). Seventeen (25%) patients relapsed: 9/40 (22%) had early-stage disease, and 8/19 (42%) had advanced-stage disease. Splenic involvement, mediastinal disease, extranodal disease, and slow early response were independent predictors of relapse risk.ConclusionPediatric patients with early-stage NLPHL have an excellent prognosis, with a 5-year OS of 100%. However, those with advanced stages had a high relapse rate. R-CHOP was associated with a better response and relapse-free rate than ABVD.

Mesenchymal tumors of the mediastinum: analysis of the clinical case

Mediastinal tumors include a wide range of benign and malignant neoplasms. The latter in the early stages are characterized by a long latent course and carry a significant threat of com pression and / or invasion of vital organs of the mediastinum. The complexity of their diagnosis is complemented by a mixed clinical picture, similar to other somatic diseases. Considering all of the above, mediastinal tumors are an urgent problem for the modem oncological community, they require improving knowledge and gaining experience in their surgical and conservative treatment. Mesenchym al tumors of the mediastinum make up a small part of tumors of the mediastinal space, and the low incidence of neoplasm s of this anatomical localization dictates the need for an interdisciplinary approach to the diagnosis and treatment of mesenchym al tumors of the mediastinal space. A clinical case of the disease is considered, an effective and radical surgical treatment method is demonstrated. The asymptomatic course of the early stages of the disease, as w ell as the relatively low effectiveness of surgical intervention in the late period of oncogenesis, dictates the need to search for new approaches in the diagnosis and treatment of mediastinal tumors.

Thoracoscopic minimally invasive surgical treatment with the same incisions in a patient with uremia complicated with large thymoma and right upper lobe lung cancer: a case report

A 41 year old female with stage 5 chronic kidney disease undergoing hemodialysis was admitted to the hospital. Chest CT scan revealed a large mass lesion of approximately 6.0 × 3.5x4.9 cm in size in the anterior superior mediastinum and a ground glass nodule in the upper lobe of the right lung, which increased in size from 9 × 7 mm 1 year and 9 months ago to 11mmx9mm before surgery. We designed a localization method to accurately locate the pulmonary nodule and successfully performed thoracoscopic minimally invasive resection of both thymoma and lung cancer through a subxiphoid approach with the same incision for this patient. With the support of perioperative hemodialysis, the patient's outcome is good. The pathological diagnosis of the anterior mediastinal mass is thymoma (b1 type), and the pathological diagnosis of the right upper lobe nodule is invasive lung adenocarcinoma (acinar type). This report describes the diagnosis and treatment process of the case.

Cardiac Angiosarcoma with Unusual Cytologic Features Causing Cardiac Tamponade in a Young Adult Patient

Abstract Introduction/Objective Cardiac angiosarcoma is a rare endothelial malignancy with poor prognosis, frequent metastasis, and short median survival of only a few months. The disease has a wide age spectrum and can occur in young adult patients. The cytological diagnosis of cardiac angiosarcomas is challenging as cases are rare and its cytology is not extensively described or reported in literature. Here, we describe a rare case of cardiac angiosarcoma with unusual cytologic features. Methods/Case Report Our patient is a 30 year old male presenting with three days of worsening dyspnea and palpitations and was discovered on ultrasound to have large pericardial effusion compressing the right ventricle and causing cardiac tamponade. CT/MRI imaging revealed a 4.5 x 4.3 x 2.6 cm mass inside the right ventricle with extra- cardiac invasion through the pericardium and into the anterior mediastinum. Pericardiocentesis yielded 1.5 liters of hemorrhagic, brown, pericardial fluid with elevated LDH and protein levels. Cytology of the pericardial fluid revealed numerous tumor cells occurring singly or in monolayered, acinar clusters or cohesive spheres containing amorphous, eosinophilic cores made of collagen as evidenced on trichrome stain. The tumor cells possessed hyperchromatic, irregular, variably sized nuclei, prominent nucleoli, and cytoplasmic vacuoles. The tumor cells were positive for vimentin, CD31, and CD34, and showed high Ki67 proliferation index > 50%. A catheter-mediated biopsy of the right ventricular mass revealed spindled and epithelioid tumor cells strongly positive for CD31, CD34, and vimentin, focally positive for Factor VIII and AE1/AE3, and showing high Ki67 proliferation index of roughly 50%. The cytological, histological, and immunohistochemical findings were most consistent with cardiac angiosarcoma as the diagnosis. The patient eventually developed worsening chronic left chest pain and expired from cardiac arrest six months after his diagnosis. Results (if a Case Study enter NA) NA Conclusion We report a rare case of cardiac angiosarcoma with unusual cytologic features, manifesting as acinar clusters and cohesive spheres with collagenous cores that are not typical of malignant endothelial neoplasms. Currently there are no effective, standardized therapies that can significantly prolong survival for this malignancy, and treatment is often palliative. The cytological diagnosis of cardiac angiosarcoma is challenging given the rarity of this disease and the paucity of literature describing its cytology.

Endoscopic Tunnel Dissection of an Oesophageal Bronchogenic Cyst: A Case Report

Introduction: A bronchogenic cyst is a very rare congenital malformation typically found in the middle and superior mediastinum. Infrequently, it can be located in the pericar-dium, diaphragm, oesophagus, and stomach. Intramural oesophageal bronchogenic cysts are highly uncommon, and because of this, they have not been extensively studied. They are gen-erally asymptomatic; however, due to their potential to cause complications, such as evolution into malignancy, the removal of these cysts is recommended. Routinely, techniques, including thoracotomy and thoracoscopy, have been adopted for excision. This case report details our success in performing a complete resection of an intramural oesophageal bronchogenic cyst via a novel approach of Submucosal Tunneling Endoscopic Resection (STER). Case Presentation: A 62-year-old woman was referred for an outpatient gastroscopy and co-lonoscopy for further investigation of her unexplained iron deficiency anaemia, abdominal pain, diarrhoea, and weight loss. A single oesophageal nodule was found on gastroscopy, which was further characterized and deemed to be benign on upper endoscopic ultrasound. The lesion was removed via the STER technique. During the procedure, submucosal fibres were dissected and a full-thickness myotomy was performed to completely remove the lesion. Histologically, the lesion showed a cyst lining comprising ciliated columnar epithelium, a finding consistent with a bronchogenic cyst. The patient maintained a normal diet and re-mained asymptomatic throughout the follow-up period. Conclusion: This report documents the successful resection of an oesophageal bronchogenic cyst via the STER technique. This novel approach appears to be a valuable tool with negligible invasiveness. It provides a feasible option for patients.

Gastric cyst of the posterior mediastinum in a child: An unusual presentation

Gastric cyst of the posterior Mediastinum is a rare congenital anomaly of the gastrointestinal tract. They are classified according to their embryological origin, epithelial lining and location, as thymic cyst, cystic hygroma, mesothelial cysts, thoracic duct cyst and cystic malformation of the primitive foregut. They usually present in neonates or in infancy and are discovered incidentally on radiological examination or gastric endoscopy. Accurate diagnosis of these cysts before resection is difficult and differential diagnosis are varied. This case report presents a 6-year-old boy who complained of fever for 3 weeks. Chest X-ray revealed right para median oval shaped opacity. HRCT showed a well-defined cystic lesion measuring 9x4.4x3.3 cm in the right side of the posterior mediastinum in the perihilar location. There was also noted vertebral segmentation anomaly in the cervicothoracic spine. Cystectomy was and Gastric cyst was diagnosed through histopathological examination. This case report is presented for its rarity and an unusual delayed clinical presentation.

Upfront Thoracic Magnetic Resonance Imaging for the Evaluation of Thymic Lesions to Reduce Non-Therapeutic Diagnostic Thymectomy: A Narrative Review.

Background: Thymic pathologies represent the most common lesions of the anterior mediastinum. They may be classified as malignant or benign. Current diagnostic pathways recommend an initial assessment with computed tomography (CT) imaging to delineate potentially malignant thymic lesions. Despite this, high rates of non-therapeutic thymectomy continue to be observed. This carries with it significant anaesthetic, operative, and post-operative risks, in addition to healthcare costs. Consequently, there is a growing interest in magnetic resonance imaging (MRI) as a primary diagnostic modality for lesions of the anterior mediastinum. This narrative review outlines the current approaches to the evaluation of thymic lesions, with a discussion of the strengths and limitations of CT and MRI imaging modalities. It also evaluates the current discourse on the use of upfront MRI for thymic and anterior mediastinal lesion assessment. Methods: A narrative review was performed following a search on the Medline database. Articles that were evaluated had explored the role of MRI on the evaluation of thymic and anterior mediastinal lesions. Results: Current work-up for thymic and anterior mediastinal lesions are highly variable and centre around the use of CT. Upfront MRI demonstrates a similar accuracy to CT for various thymic and anterior mediastinal pathologies; however, the efforts to integrate this approach into routine practice remain in their infancy, with no standardised guidelines that exist. Conclusions: This narrative review demonstrates that there is a paucity of evidence relating to the sensitivity and specificity of MRI compared to CT for thymic lesion analysis and their subsequent relationship with non-therapeutic thymectomy. Future prospective trials to assess the role of MRI in thymic lesion determination are required to understand whether MRI can more accurately characterise these lesions to reduce non-therapeutic thymectomy. Additionally, further research efforts are required to characterise best-practice methods for integrating MRI into diagnostic pathways for these lesions in a cost-effective and resource-conscious manner.

Mediastinal and thoracic hematoma following transradial cerebral angiography: a case report

BackgroundCerebral angiography through the transradial approach (TRA) is associated with a low risk of complications, but in rare cases, these complications can be life-threatening.Case presentationA 56-year-old female patient was admitted for transradial cerebral angiography due to the complaint of right limb weakness and the diagnosis of cerebral infarction and cerebral artery stenosis. During the procedure, the patient coughed with expectoration and complained of throat discomfort, palpitations, and pains in the right shoulder and back. Emergency CT scan indicated hematoma in the middle mediastinum and the right thoracic cavity, and perforation of a branch of the subclavian artery was highly suspected. Subclavian artery angiography was conducted immediately, which revealed a patchy contrast medium overflow in a branch of the right costocervical trunk. Selective endovascular occlusion therapy was performed successfully with gelfoam particles and placement of 2 microcoils. At 12 days after cerebral angiography, the patient recovered well and was discharged from the hospital.ConclusionMediastinal and thoracic hematoma may occur due to vessel perforation during TRA cerebral angiography, in which guidewire advancement must be cautious. Early detection and appropriate countermeasures can reduce the severity of vascular perforation and subsequent hematoma.

6487 Hypercalcemia In Pregnancy Due To An Ectopic Parathyroid Adenoma: A Diagnostic Dilemma

Abstract Disclosure: S.S. Patel: None. M.B. Sharma: None. Introduction: Hypercalcemia is a rare complication of pregnancy, with the most common cause being primary hyperparathyroidism due to a parathyroid adenoma. Ultrasound is the primary modality used for localization, as sestamibi and computed tomography (CT) carry the risk of potential harm to the fetus. We present the case of hypercalcemia in a pregnant female that failed to resolve after two gland parathyroidectomy, necessitating a sestamibi parathyroid scan to localize an ectopic parathyroid adenoma. Case: A 40-year-old pregnant woman at 12 weeks of gestation presented with hypercalcemia, with a corrected calcium level of 12.5 mg/dL (8.7-10.4 mg/dL). She complained of nausea and vomiting but denied any personal or family history of hypercalcemia. Further evaluation revealed primary hyperparathyroidism as the etiology, with Intact PTH of 429.2 pg/mL (18.5-88.0 pg/mL), ionized calcium of 1.45 mmol/L (1.12-1.32 mmol/L), 25-OH vitamin D of 16.4 ng/mL (30-100 ng/mL), phosphorus of 1.3 mg/dL (2.4-5.1 mg/dL), and creatinine of 0.71 mg/dL (0.5-0.8 mg/dL). Notably, her calcium level had been 19.2 mg/dL two weeks earlier during an episode of hyperemesis gravidarum. Hypercalcemia proved relatively resistant to treatment with intravenous hydration and subcutaneous calcitonin. Ultrasound of the neck failed to reveal a parathyroid adenoma. The patient then underwent surgical neck exploration, during which two parathyroid glands were removed, resulting in an intraoperative PTH drop from 440 to 340 pg/mL. Postoperative calcium levels remained elevated at 12.9 mg/dL, prompting the resumption of treatment. Oral sodium and potassium phosphate was added to bind dietary calcium. After an extensive multidisciplinary discussion, a 99mTc-sestamibi parathyroid scan with a lower dose of sestamibi and without CT was recommended. This revealed an ectopic parathyroid adenoma in the anterior mediastinum. Surgical removal of the ectopic parathyroid adenoma in the second trimester finally led to a significant intraoperative PTH drop from 315 to 28 pg/mL. The postoperative course was complicated by hypocalcemia and hypomagnesemia, requiring calcium, vitamin D, and magnesium supplements. These complications resolved over the following days. The patient remained normocalcemic for the remaining pregnancy and delivered a healthy male infant at 34 weeks. Conclusion: Hypercalcemia in pregnancy is associated with fetal and maternal complications, warranting adequate management and close follow-up. The use of 99mTc-sestamibi parathyroid scan is typically not recommended in pregnancy due to concern for fetal harm; however, there are a few studies showing no association with increased birth defects or adverse pregnancy outcomes at low radiotracer doses. Hence, a sestamibi parathyroid scan can be considered during pregnancy to localize an adenoma after a careful review of the benefits versus risks. Presentation: 6/2/2024

7388 Rare Case of Mediastinal Parathyroid Carcinoma

Abstract Disclosure: Y. Esaki: None. J. Moalem: None. A. Israel: None. I. Shafiq: None. Introduction: Parathyroid carcinoma accounts for 1% of primary hyperparathyroidism with an estimated prevalence of 0.005% of all cancers. Ectopic locations of parathyroid tumors have been found in 6-16% of cases, most commonly in the thyroid, the thymus, or behind the esophagus. Parathyroid carcinoma is rarely found in the mediastinum and only 30 cases have been reported in the literature. Clinical Case: A 68-year-old male without significant past medical history was evaluated by his primary care physician for constipation, polyuria and 20 lb weight loss over the past year. He presented to the hospital after blood work revealed serum calcium of 13.5 mg/dl (8.6-10.2 mg/dl). Initial hospital workup demonstrated serum calcium 12.9 mg/dl, phosphorus 2.6 mg/dl (2.7-4.5 mg/dl), 25-OH vitamin D 21 ng/ml (30-60 ng/ml), 1,25-(OH)2 vitamin D 143.0 pg/ml (19.9-79.3 pg/ml), PTH-related protein < 2.0 pmol/L (0.0-2.3 pmol/L) and PTH 1,250.0 pg/ml (15.0-65.0 pg/ml). CT scan revealed a 3.5 cm x 2.6 cm heterogeneous right paratracheal soft tissue mass with areas of calcifications with mass effect on SVC. Thyroid ultrasound showed multinodular thyroid tissues with a left 1.1 cm heterogeneous solid nodule along the mid posterior aspect as well as a 0.5 cm hypoechoic lesion inferior to the left lobe. Sestamibi scan demonstrated a large area of increased uptake corresponding to the mass seen in the superior mediastinum on CT imaging. He underwent neck exploration and left hemithyroidectomy as well as median sternotomy with resection of the paratracheal mass. Intraoperative PTH decreased from the baseline of 1,177.0 pg/ml to 65.6pg/ml following the removal of the paratracheal mass. The final pathology of right anterior mediastinal mass was consistent with a 5 cm parathyroid carcinoma with angioinvasion, intermediate lymphatic invasion, invasion into adjacent structures, and Ki67 proliferative index focally > 5%. His post-operative course was complicated by hypocalcemia, which improved with treatment with calcitriol and calcium supplementation. He declined the genetic testing. His calcium and parathyroid hormone have remained in the normal range after 1 year. Conclusion: This case illustrates a rare case of parathyroid carcinoma found in the mediastinum. It is important to recognize that parathyroid carcinoma can present in ectopic locations including the mediastinum, as this can affect the preoperative investigation and management. Fine needle biopsy (FNA) prior to the initial operation is not recommended as it is difficult to differentiate the parathyroid carcinoma from benign disease based on FNA, and it may cause tumor rupture and seeding. Also, in the mediastinal parathyroid carcinoma, localization of the lesions including the size and invasiveness is critical in order to allow for radical surgery. Presentation: 6/3/2024

6699 Primary Hyperparathyroidism With Severe Hypercalcemia Secondary to Giant Parathyroid Adenoma

Abstract Disclosure: M.P. Lieberman-Ulm: None. M.A. Yanez-Bello: None. V.S. Lagari-Libhaber: None. Background: Parathyroid adenomas are often detected in asymptomatic patients without palpable neck mass and are responsible for 80 to 85% of cases of primary hyperparathyroidism. Oversized or “Giant” parathyroid adenomas (GPAs) are defined as parathyroid adenomas that weigh more than 3.5 g. These are rare, representing less than 1.5% of parathyroid adenomas. The majority of reported cases of GPAs are associated with elevation of PTH and calcium levels, though usually not as high as is seen in patients with parathyroid carcinoma, where PTH levels typically reach greater than three times the upper limit of normal and serum calcium greater than 14 mg/dL. Clinical Case: A 73-year-old man presented with altered mental status and was found to have severe hypercalcemia (serum calcium 20.5 mg/dL, albumin 4.4 g/dL) and AKI stage III (eGFR 16 mL/min/1.73m2). Physical exam showed palpable, mobile, left-sided fullness, and further lab evaluation revealed intact PTH of 2,934 pg/mL, vitamin D, 25-OH of 24.8 ng/mL, and PTHrP of 14 ng/mL. Phosphorous level was not collected prior to treatment. Neck ultrasound was unremarkable. CT revealed a 9 cm hypodense lesion inseparable from the posterior aspect of the left thyroid lobe extending inferiorly to the posterior mediastinum at the level of the carina. Sestamibi scan showed scintigraphic evidence of parathyroid adenoma in the left tracheoesophageal groove. Patient was treated with IV fluids, zoledronic acid, calcitonin, cinacalcet and furosemide in addition to receiving hemodialysis on arrival. He then underwent resection of the mediastinal parathyroid gland. Pathology revealed parathyroid adenoma (16.6 g) without evidence of gross or microscopic invasion into adjacent structures, vascular or perineural invasion. Size greater than 3.5 g classified this mass as a giant parathyroid adenoma. Post-operatively, the patient’s PTH and corrected calcium normalized (17 pg/mL and 9.4 mg/dL, respectively). Conclusion: Giant parathyroid adenomas are a rare cause of primary hyperparathyroidism. Generally, parathyroid adenomas present with less severe clinical and biochemical characteristics than those of parathyroid carcinomas. However, the characteristics of GPA can be similar to parathyroid carcinoma, and differentiating between the two can be challenging. Parathyroid masses are differentiated with histologic diagnosis along with haematoxylin and eosin stain findings. In the case of our patient, his clinical picture was suggestive of parathyroid carcinoma given the severity of his disease, but pathology revealed parathyroid adenoma. Additionally, his calcium and PTH levels normalized after parathyroidectomy. This case may be representative of rare, aggressive giant parathyroid adenoma, however close follow up is imperative to ensure patient does not develop metastatic disease in the future, which would suggest underlying malignancy all along. Presentation: 6/2/2024

Gastric conduit reconstruction after esophagectomy.

A high risk of complications still accompanies gastric conduit reconstruction after esophagectomy. In this narrative review, we summarize the technological progress and the problems of gastric conduit reconstruction after esophagectomy. Several types of gastric conduits exist, including the whole stomach and the narrow gastric tube. The clinical outcomes are similar between the two types of conduits. Sufficient blood supply to the conduit is mandatory for a successful esophageal reconstruction. Recently, due to the availability of equipment and its convenience, indocyanine green angiography has been rapidly spreading. When the blood perfusion of the planning anastomotic site is insufficient, several techniques, such as the Kocher maneuver, pedunculated gastric tube with duodenal transection, and additional microvascular anastomosis, exist to decrease the risk of anastomotic failure. There are two different anastomotic sites, cervical and thoracic, and mainly two reconstructive routes, retrosternal and posterior mediastinal routes. Meta-analyses showed no significant difference in outcomes between the anastomotic sites as well as the reconstructive routes. Anastomotic techniques include hand-sewn, circular, and linear stapling. Anastomoses using linear stapling is advantageous in decreasing anastomosis-related complications. Arteriosclerosis and poorly controlled diabetes are the risk factors for anastomotic leakage, while a narrow upper mediastinal space and a damaged stomach predict leakage. Although standardization among the institutional team members is essential to decrease anastomotic complications, surgeons should learn several technical options for predictable or unpredictable intraoperative situations.

A unique presentation of pericardial epithelioid angiosarcoma with multifaceted complications

Introduction and importance: Angiosarcomas are rare tumors of endothelial origin and may arise in any organ. Epithelioid angiosarcomas are a subtype of angiosarcoma that are rapidly progressive and typically fatal. Case presentation: The authors report a case of a 25-year-old previously healthy female who presented initially for dyspnea and palpitations, on further evaluation she was found to have large bilateral pleural effusions and cardiac tamponade. Clinical discussion: Pericardiocentesis and thoracentesis were performed alongside biopsies that revealed atypical cellular proliferation. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed avid uptake in the anterior mediastinum, perivascular, paratracheal, subcarinal and pleural lymph nodes with large FDG uptake in the bilateral pleural effusion. Mediastinoscopy was done and biopsies showed an overtly malignant, epithelioid neoplasm with foci of vaso-formation; Keeping with high-grade epithelioid angiosarcoma of the pericardium. She received six cycles of weekly paclitaxel, but imaging for abdominal pain incidentally showed evidence of metastasis to the liver and spine so she was switched to Adriamycin-Ifosfamide for which she received one cycle so far. Her hospital course was complicated by high-output pleural effusions, chylothorax, left atrial thrombus formation and an intensive care unit stay for septic shock. Conclusion: Pericardial epithelioid angiosarcoma has been reported rarely in the literature. The authors aim to report a case of extensive metastatic pericardial epithelioid angiosarcoma in a young patient; which we believe can be an addition to the literature of a malignancy associated with poor prognosis and no definitive proven treatment regimen.

Postoperative irradiation in stage II thymomas: is it worth it?-shedding some light in the guidelines' gray zone.

Thymomas are rare, indolent tumors. Early stages (I-II) benefit from surgical treatment, while locally advanced diseases (stages III-IV) usually require a multidisciplinary approach. The role of postoperative radiotherapy (PORT) on anterior mediastinum for radically resected Masaoka-Koga stage II thymomas remains controversial. This study aims to determine the impact of PORT on the disease-free survival (DFS) of stage II thymomas. We retrospectively collected the clinical and oncologic data [age, sex, myasthenia gravis (MG) prevalence, Masaoka-Koga stage, World Health Organization (WHO) histologic subtype] of those patients who underwent radical exeresis in our Unit between January 2000 and December 2020. Kaplan-Meier estimates of DFS were then performed. Our study included 195 patients (M/F = 98/97). Almost all patients were affected by MG (90.7%) and most of them were operated by median sternotomy (93.3%). Thymoma stage was IIa in 87 cases (44.6%) and IIb in 108 cases (55.4%). The most represented histologic subtype was AB (27.7%), followed by B2 (24.6%), A (19%), B1 (14.9%) and B3 (13.8%). PORT was performed in 113 patients (58%, 39 stage IIa and 74 stage IIb). During the surveillance, 8 patients (4.1%) presented pleural recurrences and no local relapses. DFS was comparable in stage IIa and IIb patients, independently from PORT administration (p = .395 and p = .858, respectively). Moreover, PORT did not affect DFS considering the histologic subtypes (p = .304 for A and AB thymomas, p = .608 for B1, B2 and B3 thymomas). In our wide series, PORT administration didn't show any additional benefit on DFS. Therefore, based on our experience, patients with stage II thymoma who underwent radical surgery should not undergo any local adjuvant treatment.

EP.14C.04 Micro Neck Incision Combined with VATS for Resection of Superior Mediastinal Neoplasms

EP.14C.04 Micro Neck Incision Combined with VATS for Resection of Superior Mediastinal Neoplasms

The role of anatomical and functional orientation in identification of parathyroid glands for patients with parathyroidectomy.

To investigate diagnostic approaches for preoperative localization of secondary hyperparathyroidism, as well as to give surgeons with precise parathyroid gland localization and imaging so that surgery can be performed safely. The clinical data of 710 patients with secondary hyperparathyroidism who underwent surgery in our center from October 2009 to October 2023 were retrospectively analyzed. The changes in calcium, phosphorus, and parathyroid hormone levels were observed to ascertain the anatomical location and number of parathyroid glands. Among the 710 patients, 55 underwent total parathyroidectomy, the others underwent total parathyroidectomy with autotransplantation. In total, 2,658 parathyroid glands were removed, with 43 glands being removed in 35 reoperation cases. The median parathyroid hormone level at 6 months postoperatively was 13.40 (interquartile range, 7.00-29.80) pg/mL. The detection rates of the parathyroid glands before first and repeat surgeries were higher using 99mTc-MIBI SPECT/CT fusion imaging than ultrasound (P<0.05). The sensitivity of combined preoperative 99mTc-MIBI SPECT/CT and ultrasound was 92.31%, higher than that of either 99mTc-MIBI SPECT/CT fusion imaging or ultrasound alone (P < 0.05). The incidence of ectopic parathyroid glands was 23.8%, and the incidence of ectopic left lower parathyroid glands was 13.2%. The left lower parathyroid gland was the most prone to ectopia. 99mTc-MIBI SPECT/CT fusion imaging, paired with high-frequency ultrasound, can be utilized to diagnose SHPT preoperatively. The most common ectopia site is the left lower parathyroid gland, which is located primarily in the thymus and superior mediastinum. Understanding the functional anatomical distribution of the parathyroid glands is critical for developing effective surgical methods for secondary hyperparathyroidism.