Spectrum of MRI Features of Mucin-producing Neoplasms in the Abdomen and Pelvis

Swallowed drug-filled packet impaction and appendiceal neoplasm: Two rare causes of bowel obstruction detected in the same patient

Bowel obstruction, perforation and acute drug overdose due to packet rupture are known complication of "body-packing". We present the case of a 47-year-old man, who ingested drug-filled packets with acute bowel obstruction. A CT scan revealed multiple hyperdense ovoid bodies along distended and fluid-filled small bowel loops and an infiltrating appendiceal tumor with proximal packet retention. Peritoneal carcinomatosis was also observed. Urgent laparotomy confirmed the radiological findings. This study aims to highlight the coincidence of 2 exceedingly rare causes of bowel obstruction in a single patient and emphasize the need for meticulous finding evaluation in acutely ill patients to avoid the perceptual errors associated with "satisfaction of search" bias.

Axillary Lymph Nodes T2 Signal Intensity Characterization in MRI of Patients With Mucinous Breast Cancer: A Pilot Study

OBJECTIVE

To evaluate the T2 signal intensity (SI) of axillary lymph nodes as a potential functional imaging marker for metastasis in patients with mucinous breast cancer.

METHODS

A retrospective review of breast MRIs performed from April 2008 to March 2024 was conducted to identify patients with mucinous breast cancer and adenopathy. Two independent, masked readers qualitatively assessed the T2 SI of tumors and lymph nodes. The T2 SI ratio for adenopathy and contralateral normal lymph nodes was quantitatively measured using the ipsilateral pectoralis muscle as a reference. Comparisons between malignant and nonmalignant lymph nodes were made using the chi-square test for qualitative assessments and the Mann-Whitney U test for quantitative assessments.

RESULTS

Of 17 patients (all female; mean age, 48.4 ± 10.7 years; range: 29-80 years), 12 had malignant nodes, while 5 had benign nodes. Qualitative assessment revealed that the primary mucinous breast cancer was T2 hyperintense in most cases (88.2%-94.1%). No significant difference in qualitative T2 hyperintensity was observed between malignant and nonmalignant nodes (P = .51-.84). Quantitative T2 SI ratio parameters, including the ratio of mean and minimal node T2 SI to mean ipsilateral pectoralis muscle T2 SI, were higher in malignant nodes vs benign and contralateral normal nodes (P <.05).

CONCLUSION

Metastatic axillary lymph nodes exhibit high T2 SI, which could serve as a functional biomarker beyond traditional morphological assessment. Future studies should prioritize investigating more precise measurements, such as T2 mapping, and confirm these results in larger groups and across mucinous neoplasms in other organs.

The role of multimodality imaging in the selection and management of patients treated with cytoreductive surgery and HIPEC

Cytoreductive surgery (CRS) with or without hyperthermic intraperitoneal chemotherapy (HIPEC) is the mainstay of potentially curative surgical treatment for malignancies that have spread to peritoneal surfaces. This surgical procedure is however associated with high morbidity and appropriate patient selection and planning is therefore essential. Available multimodality imaging techniques include CT with oral and intravenous contrast, MRI including use of dedicated peritoneal protocol and FDG-PET/CT. These used with the correct technique, read by specialist radiologists and discussed under the auspices of a dedicated multidisciplinary team, can help to improve outcomes. We demonstrate that imaging not only provides information about peritoneal disease burden but more importantly want to shift the reader's focus to disease distribution. Our examples highlight how imaging helps avoid futile surgery by identifying patients with disease in unfavourable sites and show the strength and limitations of the various imaging modalities. We share how MR imaging can help identify multifocal and often occult sites including widespread miliary disease. Our examples provide a comprehensive overview demonstrating how imaging can help plan surgery by identifying patients who may need splenic vaccinations, counselling for stoma, egg harvesting and input from surgeons with other specialist expertise greatly increasing likelihood of achieving complete cytoreduction.

Tips and tricks for a proper radiological assessment of abdominal and pelvic lymph nodes

The assessment of lymph node dimensions is a commonly used criterion in analyzing lymphatic involvement related to inflammatory or neoplastic diseases. However, it is important to understand that the interpretation of lymph nodes goes beyond simply considering their size. A pathologic lymph node can present with enlarged dimensions, a heterogeneous appearance, increased cortex thickness, irregular contours, or a lobulated shape. In this context, it is essential to consider not only the dimensions but also the morphology, attenuation, and enhancement of lymph nodes on imaging exams. This article aims to demonstrate how characteristics of lymph nodes, beyond their size, can provide crucial insights that assist in diagnostic reasoning, focusing on computed tomography. By emphasizing different enhancement patterns, attenuation, and the potential contents related to these patterns, the study seeks to show how these features can indicate possible differential diagnoses and guide more accurate clinical assessments.

Subtle Presentation of Two Rare Gynecological Cancers in a Single Patient: A Case Report

Yolk sac tumors (YSTs) are rare germ-cell malignancies that usually develop in the gonads. Similarly, gastric-type adenocarcinoma of the endocervix (GAS) is a rare kind of gynecological cancer that has piqued interest due to its distinctive clinical and pathological features. These two malignancies in a single patient present a unique and challenging scenario. Here, we present the case of a 33-year-old female who presented with postcoital bleeding and was diagnosed with atypical glandular proliferation consistent with GAS. Interestingly, this patient had a history of a YST treated with left salpingo-oophorectomy and chemoradiation in the Philippines five years prior. A follow-up ultrasound report in the Philippines five months after treatment showed no evidence of residual disease. This case report aims to understand the predisposing factors of these neoplasms and asks if there is a link between them, which is necessary for tailoring surveillance, appropriate therapeutic approaches, and improving patient outcomes.

What is the optimum post treatment surveillance imaging protocol for low-grade appendiceal mucinous neoplasms and pseudomyxoma peritoneii?

Appendiceal mucinous neoplasms are rare and can be associated with the development of disseminated peritoneal disease known as pseudomyxoma peritonei (PMP). Mucinous tumours identified on appendicectomy are therefore followed up to assess for recurrence and the development of PMP. In addition, individuals who initially present with PMP and are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are followed up to assess for recurrence. However, despite the concerted efforts of multiple expert groups, the optimal imaging follow-up protocol is yet to be established. The purpose of this article is to review the available evidence for imaging surveillance in these populations to identify the optimum post-resection imaging follow-up protocol.

Association Between Pseudoprogression of Vestibular Schwannoma After Radiosurgery and Radiological Features of Solid and Cystic Components

BACKGROUND AND OBJECTIVES

The pathophysiology of vestibular schwannoma (VS) pseudoprogression after Gamma Knife radiosurgery (GKRS) remains unclear. Radiological features in pretreatment magnetic resonance images may help predict VS pseudoprogression. This study used VS radiological features quantified using an automated segmentation algorithm to predict pseudoprogression after GKRS treatment.

METHODS

This is a retrospective study comprising 330 patients with VS who received GKRS. After image preprocessing and T2W/contrast-enhanced T1-weighted image (CET1W) image generation, with fuzzy C-means clustering, VSs were segmented into solid and cystic components and classified as solid and cystic. Relevant radiological features were then extracted. The response to GKRS was classified into "nonpseudoprogression" and "pseudoprogression/fluctuation". The Z test for two proportions was used to compare solid and cystic VS for the likelihood of pseudoprogression/fluctuation. Logistic regression was used to assess the correlation between clinical variables and radiological features and response to GKRS.

RESULTS

The likelihood of pseudoprogression/fluctuation after GKRS was significantly higher for solid VS compared with cystic VS (55% vs 31%, P < .001). For the entire VS cohort, multivariable logistic regression revealed that a lower mean tumor signal intensity (SI) in T2W/CET1W images was associated with pseudoprogression/fluctuation after GKRS ( P = .001). For the solid VS subgroup, a lower mean tumor SI in T2W/CET1W images ( P = .035) was associated with pseudoprogression/fluctuation after GKRS. For the cystic VS subgroup, a lower mean SI of the cystic component in T2W/CET1W images ( P = .040) was associated with pseudoprogression/fluctuation after GKRS.

CONCLUSION

Pseudoprogression is more likely to occur in solid VS compared with cystic VS. Quantitative radiological features in pretreatment magnetic resonance images were associated with pseudoprogression after GKRS. In T2W/CET1W images, solid VS with a lower mean tumor SI and cystic VS with a lower mean SI of cystic component were more likely to have pseudoprogression after GKRS. These radiological features can help predict the likelihood of pseudoprogression after GKRS.

[Incidental finding of appendiceal mucinous neoplasms]

Low-grade appendiceal mucinous neoplasms (LAMN) are rare and are diagnosed in at least 0.13% of appendectomies in Germany, although significant underreporting is likely. Perforation of the tumors can result in abdominal mucinous collections, so-called pseudomyxoma peritonei (PMP). The challenge in the treatment of LAMN is the adequate approach to the incidental finding of these tumors. If a mucinous neoplasm is preoperatively suspected in cases of an acute condition, usually appendicitis, it must be weighed up whether a conservative approach is justifiable or whether immediate appendectomy is necessary. If this is the case, an intraoperative perforation of the appendix must be avoided and the complete abdominal cavity must be inspected for mucin deposits. If conservative treatment is possible, further treatment should take place at a specialized center. If the neoplasm is first found incidentally during surgery, perforation of the appendix should also be avoided and the entire abdominal cavity should be inspected for a PMP. If a PMP is present cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) should be performed in a specialized center. If LAMN are found during the postoperative histological work-up, it should be evaluated whether a perforation was present and mucin collections are noted in the surgical report. In the case of LAMN without evidence of a PMP, appendectomy is the adequate treatment. In cases of intra-abdominal mucinous collections, samples should be taken and further treatment should be performed at a center with sufficient expertise. An ileocecal resection or oncological hemicolectomy is not indicated. After adequate treatment, all patients should receive a follow-up using cross-sectional imaging (preferably magnetic resonance imaging, MRI) and determination of the tumor markers CEA, CA 19-9 and CA 125.