Durable Objective Response to Lurbinectedin in Small Cell Bladder Cancer with TP53 Mutation: A Molecular-Directed Strategy.

Small cell bladder cancer (SCBC) is a rare and aggressive disease, often treated with platinum/etoposide-based chemotherapy. Key molecular drivers include the inactivation of onco-suppressor genes (TP53, RB1) and amplifications in proto-oncogenes (MYC). We report a patient with SCBC who achieved an objective and prolonged response to lurbinectedin, which has been approved for metastatic small cell lung cancer, after developing disease progression on cisplatin/etoposide and nivolumab/ipilimumab. A genomic analysis of a metastatic biopsy prior to lurbinectedin initiation revealed a TP53 mutation and amplification of the cell cycle regulators E2F3 and MYCL. A repeat biopsy following the development of lurbinectedin resistance showed a new actionable ERBB2 alteration without significant change in the tumor mutation burden (six mutations/Mb). The present report suggests that lurbinectedin may be active and should be further explored in SCBC harboring TP53 mutations and amplifications in E2F3 and MYC family complexes.

Tumor-like conditions that mimic liver tumors.

Non-neoplastic tumor-like conditions of the liver can appear similar to hepatic neoplasms. In many cases, a biopsy is required to confirm the pathology. However, several tumor-like conditions can be correctly diagnosed or suggested prospectively, thus saving patients from unnecessary anxiety and expense. In this image-focused review, we present the ultrasound, computed tomography, magnetic resonance imaging, and positron emission tomography scan features of eight such entities. Clues that indicate the correct pathology are discussed, and the usual clinical setting is described. Many of these lesions are treated differently from true neoplasms, and the current treatment plan is discussed in many of the cases presented. After reviewing this article, the reader will have a better understanding of these lesions and the situations in which they should be included in the differential diagnosis.

MRI and PSMA PET/CT of Biochemical Recurrence of Prostate Cancer.

Prostate cancer may recur several years after definitive treatment, such as prostatectomy or radiation therapy. A rise in serum prostate-specific antigen (PSA) level is the first sign of disease recurrence, and this is termed biochemical recurrence. Patients with biochemical recurrence have worse survival outcomes. Radiologic localization of recurrent disease helps in directing patient management, which may vary from active surveillance to salvage radiation therapy, androgen-deprivation therapy, or other forms of systemic and local therapy. The likelihood of detecting the site of recurrence increases with higher serum PSA level. MRI provides optimal diagnostic performance for evaluation of the prostatectomy bed. Prostate-specific membrane antigen (PSMA) PET radiotracers currently approved by the U.S. Food and Drug Administration demonstrate physiologic urinary excretion, which can obscure recurrence at the vesicourethral junction. However, MRI and PSMA PET/CT have comparable diagnostic performance for evaluation of local recurrence after external-beam radiation therapy or brachytherapy. PSMA PET/CT outperforms MRI in identifying recurrence involving the lymph nodes and bones. Caveats for use of both PSMA PET/CT and MRI do exist and may cause false-positive or false-negative results. Hence, these techniques have complementary roles and should be interpreted in conjunction with each other, taking the patient history and results of any additional prior imaging studies into account. Novel PSMA agents at various stages of investigation are being developed, and preliminary data show promising results; these agents may revolutionize the landscape of prostate cancer recurrence imaging in the future. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Turkbey in this issue. The slide presentation from the RSNA Annual Meeting is available for this article.

A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 1: radiologic characteristics and imaging modalities.

The solitary pulmonary nodule (SPN) is frequently encountered on chest imaging and poses an important diagnostic challenge to clinicians. The differential diagnosis is broad, ranging from benign granulomata and infectious processes to malignancy. Important concepts in the evaluation of SPNs include the definition, morphologic characteristics via appropriate imaging modalities, and the calculation of pretest probability of malignancy. Morphologic differentiation of SPN into solid or subsolid types is important in the choice of follow-up and further management. In this first part of a two-part series, we describe the morphologic characteristics and various imaging modalities available to further characterize SPN. In Part 2, we will describe the determination of pretest probability of malignancy and an algorithmic approach to the diagnosis of SPN.

A practical algorithmic approach to the diagnosis and management of solitary pulmonary nodules: part 2: pretest probability and algorithm.

In this second part of a two-part series, we describe an algorithmic approach to the diagnosis of the solitary pulmonary nodule (SPN). An essential aspect of the evaluation of SPN is determining the pretest probability of malignancy, taking into account the significant medical history and social habits of the individual patient, as well as morphologic characteristics of the nodule. Because pretest probability plays an important role in determining the next step in the evaluation, we describe various methods the physician may use to make this determination. Subsequently, we outline a simple yet comprehensive algorithm for diagnosing a SPN, with distinct pathways for the solid and subsolid SPN.