Role of EBUS-TBNA/EUS-FNA and mass spectrometry for diagnosis and typing of lymph node amyloidosis: 10-year experience in two tertiary care academic centers.

BACKGROUND: The objectives of this study were to investigate the utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)/endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for the diagnosis of amyloidosis coupled with the feasibility of mass spectrometry (MS) for amyloid subtyping. METHODS: All patients who had amyloid diagnosed by EBUS-TBNA/EUS-FNA at two tertiary care centers from 2011 to 2020 were retrieved along with the MS subtype, clinical findings, and outcomes. RESULTS: Eight patients were included: seven underwent EBUS-TBNA of mediastinal lymph nodes, and one underwent EUS-FNA of a periportal lymph node. Ages ranged from 37 to 79 years (median, 69 years), with equal numbers of men and women. Presenting clinical history included one case each of follicular lymphoma, lymphoplasmacytic lymphoma, rheumatoid arthritis, possible sarcoid, cirrhosis, and chronic renal insufficiency, and one case each of suspected pulmonary and cardiac amyloidosis. All cases showed waxy, amorphous material on direct smears (n = 5) or ThinPrep slides (n = 3), which were confirmed as amyloid on Congo Red staining. Immunohistochemistry showed dominant lambda staining in two of three cases. MS was performed in all cases and identified five of the light-chain (AL) type, one of the heavy-chain/AL type, and two suggestive of AL amyloidosis. Bone marrow biopsy performed in seven patients demonstrated that three had monoclonal plasma cells and one had lymphoplasmacytic lymphoma. Two of four patients with systemic amyloidosis received chemotherapy and remained alive, whereas three with localized disease remained stable under observation. CONCLUSIONS: EBUS-TBNA/EUS-FNA is effective for amyloidosis diagnosis and provides adequate material for ancillary tests, including MS, which can identify the precursor amyloidogenic protein, leading to appropriate patient management.

The Use of the International Academy of Cytology Yokohama System for Reporting Breast Fine-Needle Aspiration Biopsy.

OBJECTIVES: To perform the first meta-analysis regarding the pooled risk of malignancy (ROM) of each category of the Yokohama system for reporting breast fine-needle aspiration, as well as assess the latter's diagnostic accuracy using this new system. METHODS: Two databases were searched, followed by data extraction, study quality assessment, and statistical analysis. RESULTS: The "Insufficient," "Benign," "Atypical," "Suspicious," and "Malignant" Yokohama system categories were associated with a pooled ROM of 17% (95% CI, 10%-28%), 1% (95% CI, 1%-3%), 20% (95% CI, 17%-23%), 86% (95% CI, 79%-92%), and 100% (95% CI, 99%-100%), respectively. When both "Suspicious" and "Malignant" interpretations were regarded as cytologically positive, sensitivity (SN) was 91% (95% CI, 87.6%-93.5%) and false-positive rate (FPR) was 2.33% (95% CI, 1.30-4.14%). A summary receiver operating characteristic curve was constructed and the pooled area under the curve was 97.3%, while the pooled diagnostic odds ratio was 564 (95% CI, 264-1,206), indicating a high level of diagnostic accuracy. When only "Malignant" interpretations were regarded as cytologically positive, the pooled FPR was lower (0.75%; 95% CI, .39%-1.42%) but at the expense of SN (76.61%; 95% CI, 70.05%-82.10%). CONCLUSIONS: Despite Yokohama's system early success, more data would be needed to unravel the system's value in clinical practice.

Case report of a breast granular cell tumor in a young transgender man.

INTRODUCTION AND IMPORTANCE: Granular cell tumors (GCTs) can be diagnostically challenging due to their rarity, diverse anatomic locations, and clinical and radiologic similarities to other more common entities. GCTs involving the breast are rare and are most commonly encountered in premenopausal cisgender women. We report an unusual case of a breast GCT in a young transgender man. CASE PRESENTATION: A 20-year-old transgender man who was on testosterone therapy for about 1 year presented with a painless, palpable mass in the right breast which radiologically resembled a lymph node. A fine needle aspiration showed morphology and immunohistochemistry consistent with a GCT. The tumor was excised by a mastectomy for therapeutic and gender-affirming purposes which confirmed the diagnosis of a breast GCT. CLINICAL DISCUSSION: Breast GCTs are most commonly found in cisgender women, however the mechanisms behind this relationship and whether transgender persons have an altered risk profile are not well understood. Breast GCTs are typically benign lesions with a low chance of recurrence following excision. CONCLUSION: GCTs are rare and poorly understood entities which have not been previously documented in transgender patients and can resemble other benign or malignant lesions.

Integrating comprehensive genomic sequencing of non-small cell lung cancer into a public healthcare system.

OBJECTIVES: Standard molecular testing for patients with stage IV non-small cell lung cancer (NSCLC) in the Canadian publicly funded health system includes single gene testing for EGFR, ALK, and ROS-1. Comprehensive genomic profiling (CGP) may broaden treatment options for patients. This study examined the impact of CGP in a publicly funded health system. METHODS: Consenting patients with stage IV NSCLC without known targetable alterations underwent CGP on diagnostic samples. Patients that had progressed on targeted therapy were also eligible. The CGP assay was a hybrid capture next generation sequencing (NGS) panel (Oncomine Comprehensive Assay Version 3, ThermoFisher). The number of actionable alterations, changes in treatment, clinical trial eligibility and costs as a result of CGP were evaluated and patient willingness-to-pay. RESULTS: Of 182 screened patients,134 (74%) had successful CGP testing. Twenty percent had received prior targeted therapy. Incremental actionable alterations were identified in 31% of patients. The most common novel targets identified were mutations in ERBB2 (exon 20 insertions), MET (exon 14 skipping) and KRAS (G12C). At data cut off (31/12/2020), 16% of patients had a change in treatment as a result of CGP. Additional clinical trial options were identified for 75% of patients. The incremental direct laboratory cost for CGP beyond public reimbursement for single gene tests was $747 CAD/case. CONCLUSION: CGP identifies additional actionable targets beyond single gene tests with a direct impact on patient treatment and increased clinical trial eligibility. These benefits highlight the value of CGP in patients with NSCLC in public health systems.

Cytomorphologic Features of Gastric-Type Endocervical Adenocarcinoma in Liquid-Based Preparations.

OBJECTIVE: Gastric-type endocervical adenocarcinoma (GAS) is a recently described, uncommon, and aggressive tumor with distinct morphologic features and HPV-independent etiology. Data on GAS in liquid-based cytology (LBC) Papanicolaou (Pap) test preparations from a North American patient population are scant. We systematically assessed the cytomorphologic characteristics of GAS in LBC from patients in Ontario and examined if glandular cell nuclear area could represent a readily assessable feature which may aid in GAS detection. STUDY DESIGN: Pap test slides preceding the diagnosis of GAS were retrieved locally or requested from outside laboratories. A structured review of 15 cytomorphologic features was performed using the available LBC Pap test slides of GAS and a set of usual-type endocervical adenocarcinomas (UEA). Morphometry of the glandular cell nuclear area was performed, and normalized values were compared to UEA and benign endocervical cells. RESULTS: At least 1 Pap test (5 ThinPrep®, 11 SurePath®, and 1 direct smear) was available for 14 patients. Original LBC Pap test diagnoses were negative for intraepithelial lesion or malignancy (NILM) (7), adenocarcinoma/carcinoma (6), atypical glandular cells (2), and adenocarcinoma in situ (1). Review detected abnormal glandular cells in 6/7 NILM cases. Honeycomb-like sheets, nuclear enlargement, and microvesicular cytoplasm were the single most common architectural, nuclear, and cytoplasmic features, respectively. Microvesicular cytoplasm (100 vs. 17%), honeycomb-like sheets (87 vs. 8%), prominent nucleoli (93 vs. 25%), and anisonucleosis (93 vs. 50%) were most discriminatory for GAS versus UEA, respectively. Yellow mucin, intranuclear cytoplasmic pseudoinclusions, and goblet/Paneth-like cells were uncommon, but unique for GAS. Glandular cell nuclear area normalized to neutrophils was found to be significantly increased in GAS compared to benign endocervical cells. CONCLUSIONS: GAS is under-recognized and may mimic reactive endocervical cells. Awareness of the tumor type and its cytomorphology is critical for early detection. Identification of glandular cells with uniform nuclear enlargement in conjunction with any of the other cytologic features may help avoid false-negative Pap results. Neutrophils may serve as convenient size reference and visual aid.

PD-L1 lineage-specific quantification in malignant pleural effusions of lung adenocarcinoma by flow cytometry.

OBJECTIVES: Pathologists encounter several challenges with programmed death ligand-1 (PD-L1) immunohistochemistry (IHC) tests in malignant effusions, including lineage specification (distinction between carcinoma vs. immune and mesothelial cells), background staining, sample fixation issues and inter-observer variability. We explored flow cytometric (FC) quantification of PD-L1 expression in malignant pleural effusions of lung adenocarcinoma patients as an alternative, automated, and objective quantification method compared to PD-L1 IHC. MATERIALS AND METHODS: We examined 23 malignant pleural effusions of TTF-1-positive adenocarcinoma were subjected to FC with a panel of antibodies against CD45, CD3, CD200, EpCAM, D2-40 (podoplanin), and PD-L1 (clone MIH1). The PD-L1 gate was established using fluorescence-minus-one (FMO) isotype controls. Lineage-specific PD-L1 surface expression was quantified and the FC tumor proportion score (TPS) was assessed. PD-L1 IHC was performed on cell block sections using Dako PD-L1 IHC 22C3 pharmDx assay and assessed by two cytopathologists blinded to the FC PD-L1 TPS. RESULTS: FC analysis allowed for the distinction between carcinoma cells (CD45-/EpCAM+/D2-40-), leukocytes (CD45+/EpCAM-/D2-40-) and mesothelial cells (CD45-/EpCAM-/D2-40+). FC PD-L1 TPS ranged from 0% to 77 %, while the 22C3 IHC PD-L1 TPS ranged from 0% to 97 %. The FC and IHC TPS values correlated positively (R = 0.8). Best concordance was observed when FC was performed and cell blocks were generated in parallel (R = 0.99). FC also allowed for simultaneous PD-L1 quantification in mesothelial and T-cells. PD-L1 expression on mesothelial cells ranged from 0% to 90.9 %, which also correlated positively with IHC TPS (R = 0.54). PD-L1 expression on T-cells was limited (0.1-2.9 %). CONCLUSION: FC permits rapid, objective and lineage-specific PD-L1 surface expression quantification with limited specimen manipulation. The FC and IHC concordance was impacted by different antibody clones being used, but the positive correlation suggests potential clinical utility, especially in malignant effusion specimens.

Implementation of PD-L1 22C3 IHC pharmDxTM in Cell Block Preparations of Lung Cancer: Concordance with Surgical Resections and Technical Validation of CytoLyt® Prefixation.

BACKGROUND: Programmed death ligand-1 (PD-L1) assessed by immunohistochemistry (IHC) is used as biomarker for pembrolizumab therapy in advanced stage lung cancer patients. However, data permitting direct performance comparison between cytology and surgical specimen types are limited since both specimens from a single tumor site are infrequently available. In addition, alcohol fixation used with cytology specimens requires technical validation of the PD-L1 IHC assay before clinical use. We here report our experience with implementation of the PD-L1 22C3 IHC pharmDxTM assay for cytologic samples at a large tertiary cancer center. STUDY DESIGN: Archival formalin-fixed (FF), paraffin-embedded cell blocks (CBs) and subsequent lung tumor resections (LTRs) from the same anatomical site were used for a direct comparison of PD-L1 tumor proportion scores (TPSs). TPS values were independently determined by one surgical lung pathologist and two cytopathologists blinded to the specimen pairs. An interim analysis was performed to facilitate the pooling of expertise among observers. After PD-L1 22C3 IHC pharmDxTM implementation for FF cytology specimens, dual-processed samples were used for a prospective technical validation of CytoLyt® prefixation (CF). Digital image analysis was performed for a subset of dual-processed specimens. RESULTS: Eighty-one CBs and LTRs were included for comparison of the specimen types. PD-L1 assessment in CBs had an accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 88.9/72.8, 66.7/73.5, 95.2/72.3, 80.0/65.8, and 90.9/79.1% for the ≥50/≥1% cutoff, respectively. The intraclass correlation coefficient was 0.84 (95% confidence interval [CI]: 0.76, 0.90), and it improved after interim analysis (before: 0.79 and after: 0.92). The overall concordance between CF and FF for the categories defined by the ≥50/≥1% cutoff values was 90.4% (95% CI: 79.0, 96.8). Similar assay performance was confirmed by digital analysis. CONCLUSIONS: PD-L1 22C3 IHC pharmDxTM shows good reliability if used with CB preparations. CF does not impact assay results significantly. Clinical validation with outcome data is needed, and digital methods of assessment should be further investigated.

Anaplastic lymphoma kinase 5A4 immunohistochemistry as a diagnostic assay in lung cancer: A Canadian reference testing center's results in population-based reflex testing.

BACKGROUND: The presence of anaplastic lymphoma kinase (ALK) rearrangement predicts response to ALK tyrosine kinase inhibitor (TKI) therapy. Fluorescence in situ hybridization (FISH) was the initial reference standard to detect ALK rearrangement, but immunohistochemistry (IHC) using D5F3 has gained acceptance as an alternative diagnostic method. ALK IHC assays using other ALK antibodies have also been used as screening methods, but data supporting their utility as diagnostic tests have not been widely reported. METHODS: Data from reflexive clinical ALK IHC test using the 5A4 clone concurrent with epidermal growth factor receptor (EGFR) mutation testing were analyzed. ALK IHC results were reported as negative (-), equivocal, or positive (+), with equivocal or positive staining validated by FISH break-apart probe testing. Treatment outcomes were reviewed for ALK IHC+ patients. RESULTS: Between 2012 and 2015, 146 (2.5%) cases were reported as ALK IHC+, 188 (3.2%) were reported as equivocal, and 5624 (94.4%) were reported as ALK IHC-. Of the ALK IHC+ cases, 131/143(91.6%) were ALK FISH+. Excluding 6 cases in which FISH was inconclusive or not performed, the positive predictive value was 95.6%, and the negative predictive value was 100%. Most specimens (n = 5352 [89.6%]) were also successfully tested for EGFR. Clinical responses to ALK TKIs were noted in 49 ALK IHC+ patients, with a median progression-free survival of 9.9 months. CONCLUSIONS: ALK 5A4 IHC can serve as a robust diagnostic test for ALK-rearranged lung cancer and is associated with treatment response and survival. Optimized tissue allocation resulted in high success rates of combined reflex EGFR and ALK testing.

Performance of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for the Diagnosis of Isolated Mediastinal and Hilar Lymphadenopathy.

BACKGROUND: Although many studies have assessed the diagnostic utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the context of a specific disease, few studies have assessed the overall diagnostic yield, sensitivity, and negative predictive value in patients with isolated mediastinal and hilar lymphadenopathy (IMHL). OBJECTIVE: We evaluated the performance of EBUS-TBNA for diagnosing IMHL in a population with a high prevalence of concurrent or preexisting non-pulmonary malignancy. METHODS: A retrospective chart review of patients who underwent EBUS-TBNA from October 2008 to April 2014 was performed to identify patients with IMHL. Patients with known or suspected primary pulmonary malignancy were excluded. When available, EBUS-TBNA results were cross-referenced with further diagnostic investigation or clinical diagnosis based on follow-up. RESULTS: EBUS-TBNA was used to sample 765 lymph nodes from 350 patients. One hundred and fourteen (33.3%) patients had a concurrent or preexisting non-pulmonary malignancy. The overall yield of EBUS-TBNA for specific diagnosis was 300/350 (86%). The diagnostic yield for sarcoidosis, lymphoproliferative disease, metastatic lymphadenopathy from extrathoracic malignancy, and necrotizing granuloma was 123/149 (83%), 27/33 (82%), 20/25 (80%), and 13/19 (68%), respectively. Amongst 50 patients with non-diagnostic EBUS-TBNA, 25 yielded an insufficient sample and another 25 yielded only benign lymphoid material which was not representative of the underlying pathology. Overall, EBUS-TBNA had a sensitivity of 89%, a diagnostic yield of 86%, and a negative predictive value of 79%. CONCLUSION: For patients with isolated hilar or mediastinal lymphadenopathy and a high background prevalence of concurrent and preexisting non-pulmonary malignancy, EBUS-TBNA is a reliable first-line diagnostic investigation.

Stratified Mucin-Producing Intraepithelial Lesion of the Cervix: Subtle Features Not to Be Missed.

OBJECTIVES: Stratified mucin-producing intraepithelial lesion (SMILE) is an uncommon premalignant lesion of the uterine cervix. A detailed examination of preinvasive SMILE cases including a comparison of the cytologic features with usual-type adenocarcinoma in situ (AIS) and human papillomavirus (HPV) genotyping was performed. STUDY DESIGN: Excisions and preceding Papanicolaou (Pap) tests were retrieved from the files of 2 tertiary care centers. Histologic review estimated the lesional SMILE proportion. Pap tests were reviewed and assessed for architectural, cellular and background features. Cobas® HPV test was performed. RESULTS: 13 cases were identified. Mean/median patient age was 35/33 years (range 23-51 years). Concurrent high-grade squamous intraepithelial lesion was found in 10/13 (77%) and AIS in 8/13 (62%) cases. In 6 cases, SMILE was dominant (≥50%) and represented in 5/6 corresponding Pap tests. Cytology interpretations differed more often in the SMILE-dominant group (p < 0.05). SMILE and AIS had overlapping features. Feathering and prominent nucleoli were absent in SMILE. HPV DNA was detected in all 12 cases tested. HPV 18 was most common (7/12). Excisions with positive/suspicious margins were reported in 5/6 SMILE-dominant versus 3/7 nondominant cases. CONCLUSION: SMILE is best considered as an AIS variant for cytologic, etiologic and management purposes. Cytologic features overlap with AIS, but are more subtle and easily missed. HPV testing may play a role in facilitating SMILE detection.

Patient-derived tumor xenograft models established from samples obtained by endobronchial ultrasound-guided transbronchial needle aspiration.

OBJECTIVES: There has been limited utility for laboratory tumor models to predict clinical performance of cancer drugs. Clinical drug trials usually recruit patients that have advanced disease, therefore preclinical tumor models that closely reflect this characteristic will be more reliable to test candidate drugs. We evaluated the use of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to sample metastatic lymph nodes in patients to establish patient-derived tumorxenograft (PDX) models of advanced lung cancer. MATERIALS AND METHODS: Cell suspensions from TBNA aspirates were implanted into the subcutaneous tissue of NSG (NOD scid) gamma) mice. The success rate of PDX establishment was associated with tumor histopathology and the cellularity and cytopathological diagnosis of the primary EBUS-TBNA samples. RESULTS: From December 2011 to June 2012, 19 patients were enrolled in this study. Successful engraftment was achieved in 8/19 cases (42.1%). The duration between inoculation and tumor formation averaged 62.4 days (13-144 days). The engrafted tumors included 3 adenocarcinomas (3/12: 25%), 2 squamous cell carcinomas (2/3: 67%), 1 large cell carcinoma (1/1: 100%), and 2 small cell carcinomas (2/3: 67%). CONCLUSION: EBUS-TBNA samples can be used for establishment of tumor xenograft model in immunodeficient mice.

Multiplex sequencing for EZH2, CD79B, and MYD88 mutations using archival cytospin preparations from B-cell non-Hodgkin lymphoma aspirates previously tested for MYC rearrangement and IGH/BCL2 translocation.

BACKGROUND: Gene rearrangements and specific translocations define some B-cell non-Hodgkin lymphoma (NHL) subtypes. Genome-wide mutational studies have revealed recurrent point mutations with prognostic implications. The goals of this study were to evaluate the feasibility of applying a multiplex mutation assay to archival cytospin preparations (CPs) and to investigate the rate of EZH2, CD79B, and MYD88 mutations in B-cell NHL samples previously tested for MYC rearrangement and/or IGH/BCL-2 translocation. METHODS: DNA was extracted from archival CPs of B-cell NHL cases with previous fluorescence in situ hybridization (FISH) assays for MYC rearrangement and/or IGH/BCL-2 translocation. Multiplex sequencing was performed for the detection of EZH2 (Y641), CD79B (Y196), and MYD88 (L265) mutations. Sanger sequencing was applied to samples with positive results and failed assays. RESULTS: Eighty-eight archival CPs were available from 40 patients. Alterations detected by FISH were: MYC rearrangement (10 cases), IGH/BCL-2 translocations (21 cases), dual translocations (6 cases), and other abnormalities for IGH/BCL-2 (23 cases) and for MYC (16 cases). DNA concentration ranged from 1.88 to 62.85 ng/µL (mean, 9.46 ng/µL). Successful results were obtained in 88.0% of the specimens submitted to multiplex sequencing. With Sanger sequencing, 2 additional mutated cases were found, and all cases with mutations were confirmed. Eight specimens showed mutations: 6 for EZH2, 1 for CD79B, and 1 for MYD88. Among them, 5 cases showed concurrent MYC and/or IGH/BCL-2 translocations and 2 revealed abnormal signals of IGH/BCL-2 and MYC. CONCLUSIONS: CPs archived for up to 6 years are a reliable source of high-quality genomic material for multiplex sequencing. Almost all B-cell NHL with point mutations showed concurrent chromosomal abnormalities.

Microcystic variant malignant mesothelioma presenting as a localized paraspinal mass.

A 58-year-old man presented with productive cough and fever. Computed tomography (CT) scan of the chest showed an upper right paraspinal mass. CT-guided fine-needle aspiration biopsy showed lobules of vacuolated cells against a background of myxoid material. The cells demonstrated moderate to severe nuclear atypia and occasional mitoses. Immunohistochemistry revealed tumor cells to be immunoreactive for calretinin, WT-1, D2-40, cytokeratin (CK) 7, AE1/AE3, high molecular weight keratin, vimentin and epithelial membrane antigen, and negative for thyroid transcription factor-1, Ber-EP4, carcinoembryonic antigen, S100 protein, CK20, and CDX2. The combined morphologic and immunohistochemical findings confirmed the diagnosis of microcystic variant of localized malignant mesothelioma. The subsequent lung resection showed a pleural-based mass in the right upper lobe and confirmed the diagnosis. Awareness of the existence of unusual morphologic variants and localized forms of mesothelioma are necessary to avoid misdiagnosis of fine needle biopsy samples. Recognition of characteristic cytomorphologic features along with optimal use of panel of immunohistochemistry studies is crucial for making a specific diagnosis.

Subclassification of lymphoproliferative disorders in serous effusions: a 10-year experience.

BACKGROUND: Rare studies have reported the application of multiple ancillary tests to the diagnosis of lymphoproliferative disorder in serous effusions. In the current study, the authors evaluated the effectiveness of using an algorithm for the triage of serous effusions and the contribution of ancillary studies to achieve a specific subtype of lymphoproliferative disorder. METHODS: Serous effusion samples that had a final diagnosis of lymphoproliferative disorder or suspicious for lymphoma were selected from cases that were diagnosed between 2001 and 2010. Data were collected on patient and sample characteristics as well as results from immunophenotype and molecular studies. RESULTS: In total, 168 serous effusions were identified from 110 patients. The most common site of involvement was the pleural cavity (n = 133) followed by the peritoneal cavity (n = 30) and pericardial cavity (n = 5). The volume of serous effusions ranged from 2 mL to 1000 mL (mean, 238 mL). In 42 patients (38.2%), serous effusions were the primary source of diagnosis. In 129 patients who had a diagnosis of LPD, either generic (n = 82) or specific (n = 47) ancillary tests were performed as a single test in 58 samples (67.4%) or as a combination of multiple studies in 19 samples (23.2%). Immunophenotyping was successful in almost all samples that had a specific subtype with 16 B-cell and 4 T-cell lymphomas being diagnosed. More samples with a specific subtype of lymphoma underwent molecular tests compared with those who had a generic diagnosis (19.1% vs 13.4%). CONCLUSIONS: Successful, specific subtyping of lymphoproliferative disorders was achieved in approximately 33% of cases that were tested for ancillary studies following an approach for the triage and aliquoting of serous effusion samples.

Docetaxel-loaded thermoresponsive conjugated linoleic acid-incorporated poloxamer hydrogel for the suppression of peritoneal metastasis of gastric cancer.

We evaluated the potential of a thermoresponsive hydrogel consisting of conjugated linoleic acid-coupled Pluronic F-127 (Plu-CLA) as a controlled release, intraperitoneal delivery system for docetaxel with the aim of treating peritoneal dissemination of gastric cancer. Previously, we established a peritoneal metastasis model that involves the injection of BALB/c mice with TMK1 human gastric cancer cells. One week after the TMK1 cells were injected, the mice were injected intraperitoneally with docetaxel alone or docetaxel-loaded Plu-CLA. Tumor progression and response to therapy were monitored by micro-positron emission tomography. The total number of peritoneal tumors and the ascites volume were also measured. Compared with docetaxel alone, the combination of docetaxel and Plu-CLA (docetaxel-Plu-CLA) significantly and synergistically reduced tumor cell survival. Docetaxel-Plu-CLA showed excellent anti-tumor activity, inducing apoptosis more potently than docetaxel alone. Docetaxel-Plu-CLA also significantly reduced the number of peritoneal metastatic nodules and increased survival in the peritoneal gastric cancer xenograft model. Our results show that intraperitoneal administration of docetaxel-Plu-CLA synergistically inhibits peritoneal metastasis and prolongs survival in a peritoneal gastric cancer model. Therefore, Plu-CLA is a potential intraperitoneal-route carrier for hydrophobic docetaxel for the effective treatment of peritoneal metastatic gastric cancer.