P-O07 Endoscopic submucosal dissection for giant esophageal lipomatous tumors

Background Thoracotomy is the foremost choice of giant esophageal lipomatous tumors in previous studies, but it is highly traumatic and possibly diminishes the quality of patients’ life. To minimize such impacts, a minimally invasive method without loss of curability is desirable for giant lipomatous tumors of the esophagus. With recent progress in endoscopic techniques and devices, endoscopic submucosal dissection (ESD) has been successfully used to remove esophageal or gastric submucosal tumors (SMTs). Methods Objective: To evaluate the clinical impact of ESD for giant esophageal lipomatous tumors. Design: Single-center, retrospective study. Setting: Academic medical center. Patients: Six patients with six giant lipomatous tumors of the esophagus between February 2013 and December 2020. Interventions: ESD. Main Outcome Measurements: Procedure duration, en bloc resection rate, complications, local recurrence, and distant metastases. Results Endoscopic en bloc resections of esophageal lipomatous tumors were successfully performed in all patients, with a mean duration of 56.5 ± 26.0 min. All en bloc resection lesions showed both lateral and deep tumor-free margins. The average maximum diameter of the esophageal lipomatous tumors was 171.7 ± 66.2 mm. No complications such as bleeding and perforations happened during hospitalization with 4.0 ± 1.6 days. Besides, local recurrence and distant metastasis have not occurred during the follow-up period. Conclusions ESD was a safe and effective way to dissect giant lipomatous tumors of the esophagus thoroughly.

Spindle Cell Lipoma with Ossification Mimicking Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma: A Case Report

Although spindle cell lipoma (SCL) is a subtype of lipoma, the characteristics of SCL are observed in both lipomatous and non-lipomatous tumors. In this article, we present a case of SCL with ossification mimicking atypical lipomatous tumors/well-differentiated liposarcomas (ALTs/WDLs). Considering the findings of magnetic resonance imaging and needle biopsy, which exhibited ALTs/WDLs, marginal resection was performed. Histopathological findings demonstrated mature adipocytes and spindle cells without atypia and no malignant osteoid tissue in the ossified region. In addition, immunohistochemistry (IHC) showed positive staining for CD34, heterogeneous retinoblastoma protein deficiency, and negative staining for mouse double minute 2 homolog (MDM2) and cyclin-dependent kinase. Fluorescence in-situ hybridization showed negative amplification of MDM2. The final diagnosis of the tumor was established using IHC as an extremely rare SCL with ossification.

The Utility of Chest Imaging for Surveillance of Atypical Lipomatous Tumors

Synopsis. For ALTs, the utility of chest surveillance has not been well defined. This study suggests that chest imaging does not have a significant role in the surveillance of ALTs. Advanced local imaging and more intensive chest surveillance may be considered in cases of local recurrence. Background. Unlike other soft tissue sarcomas, atypical lipomatous tumors (ALTs) are thought to have a low propensity for metastasis. Despite this, a standard of care for pulmonary metastasis (PM) surveillance has not been established. This study aimed to evaluate the utility of chest imaging for PM surveillance following ALT excision. Methods. This was a multi-institution, retrospective review of all patients with primary ALTs of the extremities or superficial torso who underwent excision between 2006 and 2018. Minimum follow-up was two years. Long-term survival was evaluated using the Kaplan–Meier method. Results. 190 patients with ALT were included. Average age was 61.7 years and average follow-up was 58.6 months (24 to 180 months). MDM2 testing was positive in 88 patients (46.3%), and 102 (53.7%) did not receive MDM2 testing. 188 patients (98.9%) had marginal excision, and 127 (66.8%) had marginal or positive margins. Patients received an average of 0.9 CT scans and 1.3 chest radiographs over the surveillance period. 10-year metastasis-free survival was 100%, with no documented deaths from disease. Conclusions. This study suggests that chest imaging does not have a significant role in PM surveillance following ALT excision, but advanced local imaging and chest surveillance may be considered in cases of local recurrence or concern for dedifferentiation.

PLAG1 Immunohistochemical Staining Is a Surrogate Marker for PLAG1 Fusions in Lipoblastomas

Background The hallmark of lipoblastoma is a PLAG1 fusion. PLAG1 protein overexpression has been reported in sporadic PLAG1-rearranged lipoblastomas. Methods We evaluated the utility of PLAG1 immunohistochemical staining (IHC) in 34 pediatric lipomatous tumors, correlating the results with histology and conventional cytogenetics, FISH and/or next generation sequencing (NGS) results. Results The study included 24 lipoblastomas, divided into 2 groups designated as “Lipoblastoma 1” with both lipoblastoma histology and PLAG1 rearrangement (n = 16) and “Lipoblastoma 2” with lipoblastoma histology but without PLAG1 cytogenetic rearrangement (n = 8), and 10 lipomas with neither lipoblastoma histology nor a PLAG1 rearrangement. Using the presence of a fusion as the “gold standard” for diagnosing lipoblastoma (Lipoblastoma 1), the sensitivity of PLAG1 IHC was 94%. Using histologic features alone (Lipoblastoma 1 + 2), the sensitivity was 96%. Specificity, as defined by the ability to distinguish lipoma from lipoblastoma, was 100%, as there were no false positives in the lipoma group. Conclusions Cytogenetics/molecular testing is expensive and may not be ideal for detecting PLAG1 fusions because PLAG1 fusions are often cytogenetically cryptic and NGS panels may not include all partner genes. PLAG1 IHC is an inexpensive surrogate marker of PLAG1 fusions and may be useful in distinguishing lipoblastomas from lipomas.

Adrenocortical adenoma with myelolipomatous metaplasia: a potential diagnostic pitfall: a case report and review of the literature

Background Adrenal incidentalomas are often found during investigation for another tumor or unrelated problems. Except for adrenal myelolipoma (second most common primary adrenal incidentaloma following adrenocortical adenomas), adrenal lipomatous tumors are uncommon generally and are often described as case reports in the literature. Since the amount of fat is variable, without the help of advanced imaging techniques, some adrenal lipomatous tumors may be misdiagnosed before pathologic examination. Herein, we report a case of adrenal adenoma with myelolipomatous metaplasia that was excised as a periceliac mass in the setting of recurrent pancreatic cyst. Case report A 45-year-old Iranian woman with hypertension and end-stage renal disease presented with recurrence of a pancreatic cyst (previous pathologic report was mucinous cyst adenoma). During exploratory laparotomy, the mentioned pancreatic cyst was tightly attached to the stomach and jejunum. There was also a periceliac round rubbery lesion (firstly diagnosed by endoscopic ultrasound) that was excised for ruling out malignancy. Histologic examination of the periceliac mass was found to be adrenocortical adenoma with foci of myelolipomatous metaplasia. The pancreatic cyst histology was just a pseudocyst. Conclusion Our case highlights the significance of complete evaluation of incidental findings before surgical intervention, even in the setting of another primary tumor. Myelolipoma and myelolipomatous change (metaplasia) are two different entities. Although very similar as to pathogenesis, there are still some differences.

Big and deep seated lipomatous tumours in children : results of surgical treatment

The objective of the study is aimed to evaluate results of our pediatric patients with big and deep-seated lipomatous tumors Results of 32 children who underwent resection for 5 cm or larger and deep-seated lipomas were evaluated. The mean age of the patients was 9.1 years (range, 0-16 ; 11 female/21 male), and median follow-up period was 3.21 years (range, 1-10 years). The median size of the excised tumour was 11 cm (range, 6-28 cm) in maximal dimension. Big lipomas in children can be treated with marginal resection procedures without biopsy with lower complication and local recurrence ratio compared to adult patients with similar tumours in similar size and location.

Dorsal epidural “Spindle Cell Lipoma” in a pregnant female

Background: Spindle cell lipoma (SCL) constitutes just 1.5% of all lipomatous tumors. They typically occur in the upper back and shoulders. Here, we report a 37-year-old female presenting with a SCL in the dorsal epidural thoracic spine, during her 9th month of pregnancy. Case Description: A 37-year-old female presented with a subacute (2 months) progressive paraparesis during her 9th month of pregnancy. The MR showed a dorsal epidural mass at the D8 level. Following a cesarean section, the patient underwent a laminectomy for tumor excision. Microscopically, the lesion proved to be a SCL. At 5-year follow-up, there was no tumor recurrence. Conclusion: SCL represents a variant of benign lipomas that may occur in the dorsal thoracic spine. Gross total excision may be followed by a benign clinical course without recurrence or malignant degeneration. Very atypical SCLs need closer follow-up to avoid the misdiagnosis of liposarcoma.

Big and deep seated lipomatous tumours in children : results of surgical treatment

The objective of the study is aimed to evaluate results of our pediatric patients with big and deep-seated lipomatous tumors Results of 32 children who underwent resection for 5 cm or larger and deep-seated lipomas were evaluated. The mean age of the patients was 9.1 years (range, 0-16 ; 11 female/21 male), and median follow-up period was 3.21 years (range, 1-10 years). The median size of the excised tumour was 11 cm (range, 6-28 cm) in maximal dimension. Big lipomas in children can be treated with marginal resection procedures without biopsy with lower complication and local recurrence ratio compared to adult patients with similar tumours in similar size and location.