Pseudomesotheliomatous Carcinoma of the Lung with Morphological Characteristics of Signet Ring Cell Carcinoma: An Autopsy Case Report.

A 50-year-old woman presented with left pleural effusion. A pleural fluid cell-block specimen and longitudinal lymph node needle biopsy suggested signet ring cell carcinoma (SRCC). Although computed tomography showed a consolidation shadow in the left lower lobe, a left lung biopsy could not be performed. Upper gastrointestinal endoscopy revealed no malignancies. We administered carboplatin, pemetrexed, ipilimumab, and nivolumab for lung cancer; however, she died due to progressive respiratory failure. Pathological autopsy revealed that the left pleura was thickened as in mesothelioma, based on which pseudomesotheliomatous carcinoma of the lung (PMCL) was diagnosed. PMCLs exhibiting an SRCC morphology are rare.

Comprehensive genomic profiling of Japanese patients with thoracic malignancies: A single-center retrospective study.

BACKGROUND: Few studies have been conducted on comprehensive genomic profiling (CGP) panels in Japanese patients with thoracic malignancies after completing standard treatment. Consequently, its value in clinical practice remains unclear. METHODS: We conducted a retrospective study of Japanese patients with thoracic malignancies who underwent CGP between June 2019 and November 2022 at our hospital. We evaluated the detection rate of actionable genetic alterations and percentage of patients who received genomically-matched therapy. Furthermore, we examined the value of the CGP panel in patients who underwent multiplex gene-panel testing prior to their initial treatment. This study was performed in accordance with the principles of the Declaration of Helsinki. RESULTS: The study included 56 patients, of whom 47 (83.9%) had actionable genetic alterations and 8 (14.3%) received genomically-matched therapy. Of these, four patients were treated with approved drugs and three patients were treated with investigational agents. In addition, one patient was treated with approved drugs using the patient-directed care system. Of the 17 patients who had multiplex gene-panel testing performed at the start of their initial therapy, two (11.8%) were newly identified by the CGP panel and subsequently received genomically-matched therapy. EGFR L718Q and MET amplification were observed in two of the seven patients with epidermal growth factor receptor-tyrosine kinase inhibitor resistance. CONCLUSIONS: The CGP panel could identify genetic alterations, thereby facilitating genomically-matched therapy, even in patients with thoracic malignancies who could not be identified using multiplex gene-panel testing.