Impact of an online reference system on the diagnosis of rare or atypical abdominal tumors and lesions.

The purpose of the present study is to evaluate whether an online reference system (ORS, STATdx Elsevier, Amsterdam, Netherlands) impacts finding the histologically confirmed diagnosis of rare or atypical abdominal tumors and lesions in radiologic imaging. In total, 101 patients with rare tumor entities or lesions and atypical manifestations of common tumors were enrolled retrospectively. Blinded readings were performed by four radiologists with varying levels of experience, who reported on: (a) correct diagnosis (CD), (b) time needed to find the diagnosis, and (c) diagnostic confidence, initially without followed by the assistance of the ORS. The experienced reader (3 years of experience post-residency, CD 49.5%), as well as the advanced reader with 1 year of experience post-residency (CD 43.6%), and a resident with 5 years of experience (CD 46.5%) made the correct diagnosis more frequently compared to the less experienced reader (CD 25.7%). A significant improvement in making the correct diagnosis was only achieved by the advanced reader, the resident with 5 years of experience (CD with ORS 58.4%; p < 0.001). The advanced reader with 1 year of experience post-residency improved slightly (CD ORS 47.5%). The experienced reader (CD ORS 50.5%) and the less experienced reader (CD ORS 27.7%) did not improve significantly. The overall subjective confidence increased significantly when ORS was used (3.2 ± 0.9 vs. 3.8 ± 0.9; p < 0.001). While the ORS had a positive impact on making the correct diagnosis throughout all readers, it favored radiologists with more clinical experience rather than inexperienced residents. Moreover, the ORS increased the diagnostic confidence of all radiologists significantly. In conclusion, the ORS had no significant impact on the diagnosis of rare or atypical abdominal tumors and lesions except for one reader. The greatest benefit is the increase in diagnostic confidence.

Impact of pre-treatment extracellular volume fraction measured by computed tomography on response of primary lesion to preoperative chemotherapy in abdominal neuroblastoma.

OBJECTIVES: To retrospectively investigate the impact of pre-treatment Extracellular Volume Fraction (ECV) measured by Computed Tomography (CT) on the response of primary lesions to preoperative chemotherapy in abdominal neuroblastoma. METHODS: A total of seventy-five patients with abdominal neuroblastoma were retrospectively included in the study. The regions of interest for the primary lesion and aorta were determined on unenhanced and equilibrium phase CT images before treatment, and their average CT values were measured. Based on patient hematocrit and average CT values, the ECV was calculated. The correlation between ECV and the reduction in primary lesion volume was examined. A receiver operating characteristic curve was generated to assess the predictive performance of ECV for a very good partial response of the primary lesion. RESULTS: There was a negative correlation between primary lesion volume reduction and ECV (r = -0.351, p = 0.002), and primary lesions with very good partial response had lower ECV (p < 0.001). The area under the curve for ECV in predicting the very good partial response of primary lesion was 0.742 (p < 0.001), with a 95 % Confidence Interval of 0.628 to 0.836. The optimal cut-off value was 0.28, and the sensitivity and specificity were 62.07 % and 84.78 %, respectively. CONCLUSIONS: The measurement of pre-treatment ECV on CT images demonstrates a significant correlation with the response of the primary lesion to preoperative chemotherapy in abdominal neuroblastoma.

Treatment and outcomes in pediatric inflammatory myofibroblastic tumors - A systematic review of published studies.

Inflammatory myofibroblastic tumor (IMT) is a soft tissue neoplasm which can be locally invasive, recur, or in rare cases metastasize. Often originating from the abdomen or thorax, IMT most commonly affects children and young adults. Due to its rarity comprehensive reports detailing clinical management and outcome(s) are sparse and often based on limited index case numbers. This study systematically analyzes outcome metrics of pediatric IMT and identifies risk factors for mortality. Medline/Embase databases were searched in accordance with PRISMA guidelines. Final analysis included 57 studies with 673 IMT patients (355 males, 53 %). Individual patient data was available for 405 cases with a median follow-up period of 36 months. Tumor sites included abdomen/pelvis (n = 233, 58 %), thorax (n = 125, 31 %), head/neck (n = 34, 8 %), and extremities (n = 13, 3 %). Surgical tumor resection was the mainstay of treatment, while only 20 patients (5 %) were treated non-operatively. Recurrence(s) were reported in 80 patients (20 %) with 34 (12 %) requiring reoperation. Positive tumor margins were a significant risk factor for tumor recurrence (p < 0.0001). Chemo/radiotherapy was reported in 98 patients (25 %). Most patients (94 %) survived; 81 % (n = 237) with no evidence of recurrent disease, 14 % (n = 41) were alive with disease, and 25 (6 %) died of disease. Positive margins at primary operation, and metastatic disease were associated with mortality (p < 0.0001 for both). IMT is a rare tumor with favorable outcome for the majority of patients. Whilst most patients will present with benign tumors, complete surgical resection (R0) is crucial, as positive surgical margins are a significant risk factor for tumor recurrence and mortality.

Intraoperative radiofrequency ablation for unresectable abdominal paraganglioma: a case report.

For pheochromocytoma and paraganglioma (PPGL), the efficacy of percutaneous ablative therapies in achieving control of metastatic tumors measuring <3 cm had been demonstrated in only few reports, and intraoperative radiofrequency ablation (RFA) of locally invasive primary PPGLs has not been reported. We presented the case of a 31-year-old man who had a 9-cm functioning unresectable PPGL. He was treated with 13 cycles of cytotoxic chemotherapy without objective tumor response, according to the Response Evaluation Criteria in Solid Tumors (RECIST). Subsequently, magnetic resonance imaging revealed a 9.0 × 8.6 × 6.0-cm retroperitoneal mass that extended to the inferior portion of the inferior vena cava, the inferior mesenteric artery, and the infrarenal aorta. Biochemical evaluation demonstrated high level of plasma normetanephrine (20.2 nmol/L, normal range <0.9 nmol/L). Genetic investigation showed the germline pathogenic variant c.1591delC (p. Ser198Alafs*22) in the SDHB gene. I131-metaiodobenzylguanidine scintigraphy was negative and Ga68-dotatate PET-CT scan showed high tumor uptake without distant metastases. On open laparotomy, tumor debulking was not possible. Therefore, intraoperative RFA was performed by a highly experienced team of interventional radiologists. At 12 months after the RFA, the tumor volume decreased from 208 to 45 mL (78%), plasma normetanephrine decreased from 20.2 to 2.6 nmol/L (87%), and the doxazosin dose was reduced from 16 to 8 mg/day. To our best knowledge, this was the first report on intraoperative RFA that markedly reduced the size of a large primary unresectable PPGL, along with clinical and biochemical responses.

Diffuse abdominal lymphangiomatosis without tumoral masses: a case report.

Diffuse abdominal lymphangiomatosis is a rare and complex disease. It typically presents with non-specific gastrointestinal symptoms and characteristic cystic lesions or tumoral masses on imaging based on the literature to date. This report presents the rare case of a young man with an atypical form of diffuse abdominal lymphangiomatosis in the complete absence of cystic lesions or lymphangioma tumoral masses, thus presenting a unique diagnostic challenge. It was successively treated by surgery, gastric electrical stimulator, sirolimus, and imatinib.

Intra-Abdominal Epithelioid Neoplasm With EWSR1::CREB Fusions Involving the Kidney: A Clinicopathologic and Molecular Characterization With an Emphasis on Differential Diagnosis.

Soft tissue neoplasms, harboring fusions between EWSR1 and FUS with genes encoding CREB transcription factors family (ATF1, CREB1, and CREM), are an emerging heterogeneous group of mesenchymal tumors that differ significantly in morphology, immunophenotypes, and behavior. Recently, EWSR1/FUS::CREB fusions have been recognized to define a group of aggressive neoplasms of epithelioid morphology with multiple growth patterns and a striking predilection for mesothelial-lined cavities. These neoplasms presenting as a primary neoplasm of intra-abdominal visceral organs are rare, which could elicit a wide range of differential diagnoses because of their diverse morphologies and immunohistochemical profiles. We report 3 cases of intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions involving the kidney. This study included 2 female patients and 1 male patient, with age at presentation ranging from 17 to 61 years (mean: 32 years). All the patients underwent radical nephrectomy without adjunctive therapies. Grossly, the tumors were large, and all were solitary masses with sizes ranging from 5.6 to 30.0 cm (mean: 14.5 cm). Histologically, the neoplasms showed infiltrating and indistinct borders and were composed predominantly of monomorphic round-to-epithelioid cells with variable amounts of pale-to-clear cytoplasm, arranged in cords, nests, and sheets and embedded in a sclerotic hyalinized stroma with variable lymphoid cuffing either intermixed or at the periphery. Notably, a hemangiopericytomatous growth pattern was commonly seen. Nuclear atypia was mild, and mitotic activity was scarce. Immunohistochemically, all 3 cases were at least focally positive for epithelial membrane antigen and keratin AE1/AE3, with 2 tumors showing focal MUC4 expression and 1 case displaying diffuse CD34 and focal CAIX positivity. Targeted RNA sequencing identified EWSR1::CREM fusion in 2 cases and EWSR1::ATF1 fusion in 1 case. Subsequent fluorescence in situ hybridization analysis confirmed the RNA sequencing results. On follow-up, 1 patient developed multiple spinal bone metastases 5 months after the surgery while the other 2 patients were free of disease 9 and 120 months after diagnosis, respectively. Our findings demonstrate that intra-abdominal epithelioid neoplasms with EWSR1::CREB fusions may rarely occur primarily in the kidney and should be included in the differential diagnosis of primary renal epithelioid mesenchymal neoplasms.

Technical Considerations in Surgical Resection of Desmoplastic Small Round Cell Tumors.

Abdominal metastatic disease is a nearly universal feature of Desmoplastic Small Round Cell Tumor. The presence of this large tumor burden can be dissuasive to surgeons. Aggressive attempts at resection of all of the dozens to hundreds of nodules in the abdomen are often fraught with difficulty. This author has operated on over 200 patients with Desmoplastic Small Round Cell Tumor and offers technical considerations that aid in complete removal of all intraabdominal tumors (sarcomatosis) with an organ sparing approach. The most challenging portion of the operation is resection of the pelvic tumor in the pouch of Douglas without removing either the bladder or the rectum. These tumors are almost always large and adherent to the bladder and rectum. The desired result should be a partial peritonectomy without any evidence of gross, visible disease.

Lumps and Bumps on the Abdominal Wall: Role of Fine Needle Aspiration Cytology.

OBJECTIVE: Abdominal wall masses often pose diagnostic challenges for clinicians due to their nonspecific symptoms. They include a wide spectrum of lesions ranging from inflammatory to tumor-like masses and malignancies. The majority of the malignant nodules are metastatic in origin and may be the initial presentation of a primary malignancy; hence, an early diagnosis is important. Fine-needle aspiration cytology (FNAC) is a valuable diagnostic tool in the evaluation of such lesions. This was a retrospective study of the cytomorphological spectrum of abdominal wall masses, conducted at a tertiary health care centre over a three-year period. MATERIAL AND METHODS: The study included patients of all age groups presenting with an abdominal wall mass. These lesions were assessed by FNAC. The diagnosis was made on cytology smears and subsequently correlated with the histopathological diagnosis, wherever possible. RESULTS: Of the 70 cases, 21 were non-neoplastic and 49 neoplastic. A benign neoplasm was the most common lesion (52.9%), followed by non-neoplastic lesions (30%) and malignant neoplasms (17.1%). Lipoma was the most common benign neoplasm and metastasis was the commonest malignant neoplasm. The most common type of tumor metastasising was adenocarcinoma and the primary tumors were predominantly intra-abdominal. No false-negative results were seen. CONCLUSION: Most of the abdominal wall masses display a characteristic cytomorphology, which needs to be identified and recognized by a cytopathologist for an accurate diagnosis. FNAC plays an invaluable role in the detection of metastases, especially at sites such as the umbilicus, which may be the only manifestation of an underlying advanced malignant disease.

Calcifying fibrous tumor and pathological analysis

A 55-year-old male presented to our outpatient department with complaints of upper abdominal dull pain. Gastroscopy revealed a submucosal eminence at the greater curvature of the gastric body, with smooth surface mucosa, and biopsy pathology indicated inflammation. Physical examination showed no obvious abnormalities, and laboratory results were within the normal range. Computerized tomography (CT) showed thickening of the gastric body. Endoscopic submucosal dissection (ESD) was performed,and representative photomicrographs of histologic sections were shown. (AU)

Desmoplastic small round cell tumor of the abdomen: A case report.

RATIONALE: Desmoplastic small round cell tumor (DSRCT) is a rare malignant tumor with poor prognosis, usually involving the peritoneum. There are currently no standardized treatment approaches. This study helped to further advance our understanding of DSRCT, and help to guide therapy. PATIENT CONCERNS: The patient, a 19-year-old male, presented with left-sided back pain with no obvious cause and occasional abdominal pain, and underwent abdominal electron computed tomography examination in our hospital suggesting consideration of small bowel mesenchymal tumor with possible multiple implantation metastasis in the abdominopelvic cavity. DIAGNOSES: After surgical treatment, the pathology report suggested a DSRCT, and immunohistochemistry and fluorescence in situ hybridization revealed EWSR1-WT1 gene rearrangement. Lung computer tomography and abdominal magnetic resonance imaging performed half a month later showed multiple solid nodules on the proximal septal surface of the right lung base, right posterior cardiac/right anterior inferior vena cava nodules, and multiple nodules in the abdominopelvic cavity, omenta, peritoneum, and around the liver or liver, all of which were considered as metastatic foci. INTERVENTIONS AND OUTCOMES: Patient received 5 cycles of chemotherapy after surgery. The review results showed a smaller size than before. Currently, he continues to receive treatment. LESSONS: The reported case has raised awareness of the importance of DSRCT in the treatment of chemotherapy, including its role in the differential diagnosis of abdominal tumors.

[Desmoplastic round cell tumor]. / Tumor desmoplásico de células redondas.

Desmoplastic small round cell tumor is a rare and very aggressive neoplasm that belongs to the family of "small round blue cell tumors". It has a higher incidence in males in the second decade of life. It is due to translocation t(11;22) (p13;q12). It can be located both in the abdomen and in the retroperitoneum and is characterized by nonspecific symptoms. The treatment is very varied and the one that guarantees the total cure of the patient has not yet been detected. The objective of this study is to expose a clinical case of desmoplastic tumor as an rare abdominal disease and its imaging expression.

El tumor desmoplásico de células pequeñas y redondas es una neoplasia poco frecuente y muy agresiva que forma parte de la familia de los "tumores de células pequeñas, redondas y azules". Presenta una mayor incidencia en el sexo masculino en la segunda década de la vida. Se debe a la translocación t(11;22) (p13;q12). Se puede localizar tanto en el abdomen como en el retroperitoneo caracterizándose por presentar síntomas inespecíficos. El tratamiento es muy variado y no se ha detectado todavía aquel que garantice la cura total del paciente. El objetivo del presente estudio es exponer un caso clínico de tumor desmoplásico como enfermedad abdominal infrecuente y su expresión imagenológica.

Imaging of pediatric abdominal soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper.

This paper provides imaging recommendations for pediatric abdominal tumors that arise outside of the solid viscera. These tumors are rare in children and have been categorized in two groups: abdominal wall and peritoneal tumors (desmoid tumor and desmoplastic small round cell tumor) and tumors that arise from the gastrointestinal tract (gastrointestinal stromal tumor and gastrointestinal neuroendocrine tumor). Authors offer consensus recommendations for imaging assessment of these tumors at diagnosis, during follow-up, and when off-therapy.

Synchronous Hepatoblastoma and Neuroblastoma in Two Chinese Infants.

Background: Commonly, pediatric solid tumors occur independently. Only two patients with synchronous hepatoblastoma (HBL) and neuroblastoma (NBL) have been reported. Case reports: Two Chinese infants presented with abdominal mass at 10 and 8 months. Computed tomography (CT) scans in both revealed hepatic masses with additional mediastinal or adrenal masses. Pathology confirmed synchronous HBLs in the liver and NBLs in the mediastinum and adrenal. Next generation sequencing (NGS) found no remarkable germline mutations. Both patients received gross total resections with chemotherapy before or after surgery. They were followed up for 36 and 8 months, and recovered well. Conclusion: These two cases of synchronous HBL and NBL tumors lacked significant genetic alterations.

Seminal vesicle leiomyosarcoma: Case report and literature review.

INTRODUCTION AND BACKGROUND: Primary leiomyosarcoma of the seminal vesicle is an extremely rare and highly malignant disease with less than 15 cases reported. CASE DESCRIPTION: A 34-year-old man presented with acute urinary symptoms. Imagen studies showed an abdominal mass (80 mm × 65 mm × 50 mm) with contrast enhancement, compressing the right side of the bladder but with a clear cleavage level between surrounding organs. The patient underwent a transrectal US-guided biopsy which was informed as compatible with leiomyosarcoma by immunohistochemical characterization. We performed a cystoprostatectomy and pelvic lymphadenectomy plus radiotherapy. Pathology showed a 7.5 cm × 6 cm nodular para-vesical Leiomyosarcoma histological grade 2 with 0/22 lymph nodes involved. Twelve months after the surgery no recurrences have presented. CONCLUSION: A multi-disciplinary therapeutic approach, combined with close follow-up, is mandatory to obtain good outcomes in such rare and challenging cases.

Umbilical nodule - A not always innocuous abdominal finding.

ABSTRACT: Sister Mary Joseph's nodule is an umbilical nodule found in patients with metastatic abdominal cancers. It is quite rare finding and needs a high index of suspicion for diagnosis. Detection of Sister Mary Joseph's nodule should warrant widespread search for abdominal carcinoma and it universally carries quite poor clinical prognosis. Here, we describe the case of a 28-year-old patient who presented with Sister Mary Joseph's Nodule and was found to have metastatic signet ring cell gastric carcinoma on investigation. A brief discussion about this rare condition is also presented.

Epidermotropic Cutaneous Metastasis of Colonic Adenocarcinoma Presenting as a Sister Mary Joseph Nodule.

ABSTRACT: The Sister Mary Joseph nodule is a metastatic umbilical lesion that is seen in 1%-3% of intra-abdominal and pelvic malignancies. Cutaneous metastasis of visceral malignancies is rare and has characteristic dermal or subcutaneous involvement on histopathologic examination. Epidermotropism is described as the migration of malignant cells into the epidermis and is an unusual finding in intra-abdominal malignancies and cutaneous metastases. An 81-year-old woman with a past medical history of colorectal adenocarcinoma presented to the dermatology clinic for evaluation of an enlarging, denuded umbilical mass. A tangential biopsy was obtained and sent for histopathologic examination. Histopathologic analysis demonstrated infiltration of atypical, pleomorphic cells in the dermis with spread into the epidermis, consistent with epidermotropism. An immunohistochemical panel was performed and was consistent with cutaneous metastasis of the patient's underlying adenocarcinoma. We present a case of epidermotropic cutaneous metastasis of colorectal adenocarcinoma presenting as a Sister Mary Joseph nodule, an extremely rare occurrence that has not been well-documented in the literature.