Is Ultrasound-Guided Core Biopsy as Safe as Fine-Needle Aspiration, and Does It Add Significantly to the Diagnosis of Suspected Peritoneal Malignancy?

Primary liposarcoma of the omentum: A case report

RATIONALE

Omental liposarcoma is extremely rare, and only a few reports have been published in the literature. Due to the rarity of the disease, establishing a clear diagnosis and formulating a treatment plan may be challenging for clinicians.

PATIENT CONCERNS

The patient was a 51-year-old woman who presented with a protruding mass and pain in the lower abdomen.

DIAGNOSIS

Magnetic resonance imaging revealed a tumor measuring 15 cm in diameter in the pelvis. Ovarian cancer was suspected based on pre-operative imaging findings.

INTERVENTIONS

An exploratory laparotomy was performed. Intra-operative analysis of the frozen section suggested a benign tumor.

OUTCOMES

Postoperative histopathological analysis confirmed the diagnosis of omental liposarcoma. The patient recovered well after surgery.

LESSON

This case report helps clinical oncologists to develop a comprehensive understanding of this disease and treat it accordingly.

[Alternatives of histological material collection - When and how is histological confirmation by ultrasound (US), computer tomography (CT) or endosonography (EUS) useful?]

Histological classifications of tumorous lesions together with adequate staging are necessary for stage-appropriate and personalized therapies. The indications, technical possibilities, and limitations as well as potential complications of image-guided needle biopsy by ultrasound, computed tomography, and endosonography are described. Which procedure for which organ and which lesion?

Ultrasound-Guided Omental Biopsy: Diagnostic Yield and Association With CT Features Based on a Single-Institution 18-Year Series

BACKGROUND. The greater omentum can serve as a useful target for percutaneous biopsy; in clinical practice, CT is commonly used for biopsy guidance. OBJECTIVE. The purpose of this study was to evaluate the diagnostic yield of percutaneous ultrasound (US)-guided omental biopsy and to explore the association of the diagnostic yield with prebiopsy diagnostic CT findings. METHODS. This retrospective study included 163 patients (120 women and 43 men; mean age, 65 ± 12 [SD] years; mean body mass index [BMI], 28.9 ± 7.9) who underwent US-guided omental biopsy between 2002 and 2020 at a single institution at which US served as the first-line modality for omental biopsy guidance. Biopsies were performed by abdominal radiologists without dedicated interventional radiology fellowship training. Postbiopsy clinical follow-up and imaging follow-up were reviewed to establish the ultimate diagnosis for each patient. Omental biopsies were characterized as diagnostic or nondiagnostic relative to the ultimate diagnosis. Associations were explored between diagnostic yield and findings on prebiopsy CT and biopsy US. RESULTS. US-guided omental biopsy was performed using an 18-gauge core needle biopsy technique in 156 patients and fine-needle aspiration in seven patients. The mean number of biopsy passes was 2.5 ± 1.0, and mean omental thickness near the biopsy site on CT was 2.6 ± 1.2 cm. On prebiopsy diagnostic CT, omental disease appeared infiltrative in 127 (78%) patients versus mass-forming in 36 (22%) and appeared hypoechoic in 105 (64%) patients versus iso- to hyperechoic in 58 (36%). The ultimate diagnosis was malignant tumor in 154 (95%) patients (most commonly, gynecologic tumors in 82 patients [high-grade serous adenocarcinoma in 56] and gastrointestinal tumors in 45 patients) and a benign finding in nine (6%) patients. The omental biopsy was diagnostic relative to the ultimate diagnosis in 155 (95%) patients. A diagnostic versus nondiagnostic biopsy was not associated (p > .05) with age, BMI, number of biopsy passes, or omental target thickness or attenuation. A total of 94% (120/127) of US-guided omental biopsies of infiltrative cases and 97% (35/36) of biopsies of mass-forming cases were diagnostic (p = .50). A total of 96% (102/106) of US-guided omental biopsies of hypoechoic cases and 93% (53/57) of biopsies of iso- to hyperechoic cases were diagnostic (p = .36). No complications occurred. CONCLUSION. US-guided biopsy of omental disease suspected on CT is safe and effective for tissue diagnosis. Although omental disease commonly appears on US as diffuse infiltrative thickening without a discrete target, sampling based on prebiopsy CT landmarks is diagnostic in most cases. CLINICAL IMPACT. US should be considered the first-line modality for omental biopsy guidance when feasible.