A rare case of resection of a mucinous cystic neoplasm originating from the extrahepatic bile duct with cholangioscopic imaging

A 29-year-old woman was admitted to our hospital for examination of obstructive jaundice and an extrahepatic bile duct lesion. Contrast-enhanced computed tomography revealed a 20 mm cystic lesion with a thin external capsule in the common hepatic duct. Cholangioscopy revealed translucent oval masses with capillary vessels attached to the bile duct walls. The surface was mostly smooth yet partially irregular with redness, suggesting that the masses were epithelial neoplasms. Histological findings of cholangioscopy-guided targeted biopsies of the mass showed subepithelial spindle cell proliferation with no atypical epithelium. The patient underwent an extrahepatic bile duct resection to confirm the pathological diagnosis. Immunohistochemistry of surgical specimens revealed that the spindle cells were positive for estrogen and progesterone receptors. Finally, the cystic lesion with ovarian-like stroma was diagnosed as a mucinous cystic neoplasm with low-grade intraepithelial neoplasia. This is the first report of cholangioscopic imaging of a biliary mucinous cyctic neoplasm. Cholangioscopic imaging can be helpful in the differential diagnosis of biliary neoplasms and in the determination of treatment strategies.

Genomic analysis of an aggressive hepatic leiomyosarcoma case following treatment for hepatocellular carcinoma

A 70-year-old man undergoing treatment for immunoglobulin G4-related disease developed a liver mass on computed tomography during routine imaging examination. The tumor was located in the hepatic S1/4 region, was 38 mm in size, and showed arterial enhancement on dynamic contrast-enhanced computed tomography. We performed a liver biopsy and diagnosed moderately differentiated hepatocellular carcinoma. The patient underwent proton beam therapy. The tumor remained unchanged but enlarged after 4 years. The patient was diagnosed with hepatocellular carcinoma recurrence and received hepatic arterial chemoembolization. However, 1 year later, the patient developed jaundice, and the liver tumor grew in size. Unfortunately, the patient passed away. Autopsy revealed that the tumor consisted of spindle-shaped cells exhibiting nuclear atypia and a fission pattern and tested positive for α-smooth muscle actin and vimentin. No hepatocellular carcinoma components were observed, and the patient was pathologically diagnosed with hepatic leiomyosarcoma. Next-generation sequencing revealed somatic mutations in CACNA2D4, CTNNB1, DOCK5, IPO8, MTMR1, PABPC5, SEMA6D, and ZFP36L1. Based on the genetic mutation, sarcomatoid hepatocarcinoma was the most likely pathogenesis in this case. This mutation is indicative of the transition from sarcomatoid hepatocarcinoma to hepatic leiomyosarcoma.

A case report of carcinoma of the papilla of Vater associated with a hyperplasia-dysplasia-carcinoma sequence by pancreaticobiliary maljunction

BACKGROUND

Pancreaticobiliary maljunction (PBM) is a known risk factor for biliary tract cancer. However, its association with carcinoma of the papilla of Vater (PVca) remains unknown. We report a case with PVca that was thought to be caused by the hyperplasia-dysplasia-carcinoma sequence, which is considered a mechanism underlying PBM-induced biliary tract cancer.

CASE PRESENTATION

A 70-year-old woman presented with white stool and had a history of cholecystectomy for the diagnosis of a non-dilated biliary tract with PBM. Esophagogastroduodenoscopy revealed a tumor in the papilla of Vater, and PVca was histologically proven by biopsy. We finally diagnosed her with PVca concurrent with non-biliary dilated PBM (cT1aN0M0, cStage IA, according to the Union for International Cancer Control, 8th edition), and subsequently performed subtotal stomach-preserving pancreaticoduodenectomy. Pathological findings of the resected specimen revealed no adenomas and dysplastic and hyperplastic mucosae in the common channel slightly upstream of the main tumor, suggesting a PBM related carcinogenic pathway with hyperplasia-dysplasia-carcinoma sequence. Immunostaining revealed positivity for CEA. CK7 positivity, CK20 negativity, and MUC2 negativity indicated that this PVca was of the pancreatobiliary type. Genetic mutations were exclusively detected in tumors and not in normal tissues, and bile ducts from formalin-fixed paraffin-embedded samples included mutated-ERBB2 (Mutant allele frequency, 81.95%). Moreover, of the cell-free deoxyribonucleic acid (cfDNA) extracted from liquid biopsy mutated-ERBB2 was considered the circulating-tumor deoxyribonucleic acid (ctDNA) of this tumor.

CONCLUSIONS

Herein, we report the first case of PVca with PBM potentially caused by a "hyperplasia-dysplasia-carcinoma sequence" detected using immunostaining and next-generation sequencing. Careful follow-up is required if pancreaticobiliary reflux persists, considering the possible development of PVca.

Pancreatic ductal adenocarcinomas concomitant with intraductal papillary mucinous neoplasms of the pancreas: A investigation of those clinicopathological features by analyzing 48 patients who underwent surgery for those lesions

BACKGROUND

Differences between pancreatic ductal adenocarcinomas (PDACs) concomitant with intraductal papillary mucinous neoplasm (IPMN) (C-PDACs), those without IPMN (NC-PDACs) and invasive cancers derived from IPMN (IC-Ds) have not been fully clarified.

METHODS

Forty-eight patients with C-PDAC were included to investigate the differences in 1) clinicopathological features and 2) post-operative courses among the three invasive cancer groups.

RESULTS

1) Characteristics of C-PDACs were mostly similar to those of NC-PDACs; whereas, between C-PDACs and IC-Ds, the rate of mucinous carcinoma (2%/25%, p = 0.003) and pathological stage (IA, 15%/36%, p = 0.033; III, 31%/4%, p = 0.015) significantly differed. Most C-PDACs coexisted with small, multifocal IPMNs without mural nodules. 2) Cumulative 5-year recurrence-free survival (RFS) rate related to extra-pancreatic recurrence was significantly worse in C-PDACs than in IC-Ds (35%/69%, p = 0.008) and was not significantly different between C-PDACs and NC-PDACs (35%/18%). This related to intra-pancreatic recurrence tended to be poor in the order of IC-Ds, C-PDACs, and NC-PDACs (69%/82%/93%).

CONCLUSIONS

Because characteristics of IPMNs remarkably differed between C-PDACs and IC-Ds, another algorithm specific to the early detection of C-PDACs is necessary. Appropriate post-operative managements according to the two types of recurrences may contribute to the improvement in the prognoses of C-PDACs/IC-Ds.

Suprapapillary placement of plastic versus metal stents for malignant biliary hilar obstructions: a multicenter, randomized trial

BACKGROUND AND AIMS

The efficacy of the suprapapillary placement of inside plastic stents (iPSs) for unresectable malignant hilar biliary obstructions (MHOs) is unknown compared with that of uncovered inside metal stents (iMSs). This randomized controlled trial was designed to evaluate the outcomes of endoscopic placement of these stents for unresectable MHOs.

METHODS

This open-label, randomized study was conducted at 12 Japanese institutions. The enrolled patients with unresectable MHOs were allocated to iPS and iMS groups. The primary outcome was defined as the time to recurrent biliary obstruction in patients for whom the intervention was both technically and clinically successful.

RESULTS

Among 87 enrollments, 38 patients in the iPS group and 46 patients in the iMS group were analyzed. Technical success rates were 100% (38 of 38) and 96.6% (44 of 46), respectively (P = 1.00). After transferring 1 unsuccessful iMS-group patient to the iPS group (since iPSs were deployed), the clinical success rates were 90.0% (35 of 39) for the iPS group and 88.9% (40 of 45) for the iMS group from a per-protocol analysis (P = 1.00). Among the patients with clinical success, the median times to recurrent biliary obstruction were 250 (95% confidence interval, 85-415) and 361 (95% confidence interval, 107-615) days (log-rank test, P = .34). No differences were detected in rates of adverse events.

CONCLUSIONS

This Phase II randomized trial did not show any statistically significant difference in stent patency between suprapapillary plastic versus metal stents. Considering the potential advantages of plastic stents for malignant hilar obstruction, these findings suggest that suprapapillary plastic stents could be a viable alternative to metal stents for this condition.

Sustained Eosinophilic Cholangitis Due to a Mite Allergy Mimicking Sclerosing Cholangitis

Eosinophilic cholangiopathy (EC) presents with thickening and stenosis of the bile duct wall that is histologically characterized by eosinophil infiltration. The diagnosis is often difficult. We herein report a patient who had been followed up with a diagnosis of primary sclerosing cholangitis but had a final diagnosis of EC based on eosinophilia, histological findings of bile duct and liver biopsy specimens, and a review of a previous surgical specimen of the gallbladder. Antigen tests, isolation from her house, and accidental re-exposure to the antigen revealed that the causative antigen was the mite Dermatophagoides pteronyssinus.

Mixed neuroendocrine non-neuroendocrine neoplasm of the gallbladder complicated by a pancreaticobiliary maljunction of a non-dilated biliary duct: A case report

RATIONALE

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) is a rare tumor. MiNEN of the gallbladder (GB) with pancreaticobiliary maljunction (PMJ) is extremely rare. The origin of MiNEN of the GB remains unknown; the biliary tract normally lacks neuroendocrine cells. MiNEN of the GB has a poor prognosis; because of its rarity, no treatment or management guidelines have been established yet.

PATIENT CONCERNS

A 47-year-old male presenting with right hypochondrial pain and malaise for 3 months was referred to our hospital for further management.

DIAGNOSIS

The neuron-specific enolase level was increased. Contrast-enhanced computed tomography revealed a mass of 70 mm in size with unclear boundaries in the liver. The GB was surrounded by this mass, narrowing the lumen of the GB. Many swollen lymph nodes were observed in the hepatoduodenal ligament. Endoscopic retrograde cholangiopancreatography revealed a PMJ with a non-dilated biliary duct. A percutaneous biopsy was performed on the liver mass, and the pathological findings were neuroendocrine carcinoma (NEC) (small cell type). We diagnosed a NEC of the GB, T3N1M0, stage IIIB (Union for International Cancer Control, 7th edition).

INTERVENTIONS

Because of advanced lymph node metastasis, we considered this tumor difficult to cure solely by surgical intervention. After initial chemotherapy consisting of cisplatin and irinotecan, a marked reduction in both tumor and lymph node sizes enabled conversion surgery. The pathological diagnosis of the resected tumor was MiNEN consisting of NEC and adenocarcinoma. The primary lesion was the adenocarcinoma occupying the luminal side of the GB. As a postsurgical treatment, the patient received additional irradiation therapy to the common hepatic duct and liver stump because of positive surgical margins.

OUTCOMES

At 13 months postoperatively, computed tomography findings revealed the appearance of a hypervascular liver tumor, and laboratory data showed increased serum neuron-specific enolase levels. Chemotherapy was unsuccessful, leading to the death of the patient 36 months from the date of diagnosis.

LESSONS

There are several reports on the development of MiNEN of the GB. In our case, a PMJ-related adenocarcinoma of the GB transdifferentiated into NEC. Further accumulation of cases is necessary to establish a treatment strategy for MiNEN of the GB.

[A case of mediastinal pancreatic pseudocyst diagnosed and treated successfully by endoscopic procedure]

A 60-year-old man was admitted for investigation of a mediastinal cystic lesion. During endoscopic retrograde pancreatography, the contrast medium leaked from the head of the main pancreatic duct, and the cystic fluid collected with endoscopic ultrasonography (EUS) -guided aspiration showed high levels of pancreatic enzymes. Therefore, we diagnosed mediastinal pancreatic pseudocyst. The pseudocyst shrank as a result of EUS-guided drainage, and an endoscopic nasopancreatic drainage tube was then placed to close the fistula of the pancreatic duct. This case suggests that endoscopic procedures could be useful for the diagnosis and treatment of mediastinal pancreatic pseudocyst. We review 48 case reports of mediastinal pancreatic pseudocyst and discuss the usefulness of endoscopic procedures for diagnosis and treatment.

Revisiting the significance of right bundle branch block

Background/Introduction

The right bundle branch block (RBBB) has been considered a benign finding in asymptomatic individuals. However, this concept based on a few, old, small sample size studies. Recently, the importance of the right ventricular dysfunction was focused on cardiovascular prognosis in clinical cardiology.

Purpose

To determine the prognostic value of RBBB in community-based health checkups cohort with a large sample size in recent years in Japan.

Methods

We assessed 88,089 individuals (mean age, 58.3±10.2 years; 66.1% women) who participated in annual community-based health checkups. Exclusion criteria were current or previous history of heart disease, stroke, and intraventricular block such as left bundle branch block other than RBBB. We followed them from 1993 to 2016. The primary endpoint was cardiovascular death, or all-cause death. The Cox regression model was assessed in each gender. The variables included in the multivariate analyses were age, body mass index, systolic blood pressure, hypertension, total cholesterol level, high-density lipoprotein cholesterol level, treated-hyperlipidemia, hyperglycemia, treated-diabetes, estimated glomerular filtration rate (eGFR), current smoking, and drinking habit.

Results

The prevalence of RBBB was higher in men than women (723/29,863 2.4% in men vs. 581/58,204 1.0% in women, P<0.001). In both genders, subjects with RBBB were significantly older and had higher systolic blood pressure and lower eGFR compared with individuals without RBBB.

In women, RBBB was associated with significantly increased cardiovascular mortality with multivariate-adjusted hazard ratios (HR) of 1.26 [95% confidence interval (CI), 1.03–1.54]. Then, we divided them into younger or elder groups according to the cut-off age of 65-year-old. In women ≤65-year-old, RBBB related to greater cardiovascular mortality with multivariate-adjusted HR of 1.89 [95% CI, 1.27–2.80]. However, in women >65-year-old, RBBB did not show the prognostic significance.

In men, RBBB did not reach the significant results in all participants, however, men >65-year-old with RBBB showed the significant poor prognosis with HR of 1.26 [95% CI, 1.04–1.53].

Conclusions

In this cohort study, contrary to common perception, RBBB was associated with increased cardiovascular mortality in women, especially younger women ≤65-year-old, and elderly men. To the extent we know, the present study is the largest and long-term follow-up study showing that the significance of RBBB differs depending on sex and age. Especially in young women who usually are less prone to show wide QRS, RBBB might represent the pathological abnormality. Although the pathophysiological effect of the RBBB on the cardiovascular outcome needs further investigation in the future, clinicians should alert the RBBB in young women and elder men even if they have no symptoms and evaluate the heart abnormality and follow them up carefully.

Funding Acknowledgement

Type of funding source: None

Above 25 nm emission wavelength shift in blue-violet InGaN quantum wells induced by GaN substrate misorientation profiling: towards broad-band superluminescent diodes

We report a thorough study of InGaN quantum wells spatially modified by varying the local misorientation of the GaN substrate prior to the epitaxial growth of the structure. More than 25 nm shift of emission wavelength was obtained, which is attributed to indium content changes in the quantum wells. Such an active region is promising for broadening of the emission spectrum of (In,Al,Ga)N superluminescent diodes. We observed that the light intensity changes with misorientation, being stable around 0.5° to 2° and decreasing above 2°. This relation can be used as a base for future device designing.

Arteriovenous malformation in pancreas mimicking hypervascular tumor

Arteriovenous malformation (AVM) is defined as a disease that causes blood flow abnormality due to anastomoses of the arteries and veins. AVM can occur in any gastrointestinal tract, but pancreatic AVM (P-AVM) is very rare. Previous reports demonstrated that contrast-enhanced CT (CECT) typically showed abnormal vascular network in pancreas. We present a 58-year old man with a history of acute pancreatitis. He was referred to our hospital for examination of pancreatic mass. CECT showed a round-shaped hypervascular lesion with a diameter of 8 mm in the head of the pancreas. Selective angiography showed vascular network and early visualization of superior mesenteric vein. We finally diagnosed this case as P-AVM. He underwent duodenum preserving pancreatic head resection. Histological findings confirmed the preoperative diagnosis of P-AVM.

Effects of the time-of-day (morning vs. afternoon) of implementing a combined physical and cognitive exercise program on cognitive functions and mood of older adults: A randomized controlled study

This study examined the effects of the time of conducting a combined physical and cognitive exercise program on cognitive functions and the mood of older adults. We randomly assigned 17 participants (8 men, 9 women, age 73,24±3,75) to the morning group (AM Group), 18 (8 men, 10 women, age 73,11±4,84) to the afternoon group (PM Group), and they completed a 12-week, dual-task exercise program in the morning or the afternoon, respectively. Moreover, the waiting-list control group consisted of 12 participants (6 men, 6 women, age 73,25±5,93). The cognitive functions and the mood of the participants were assessed before and after the program by using the Neurobehavioral Cognitive Status Examination, and the short version of the Profile of Mood States, respectively. As a result, the exercise program conducted in the afternoon had broader effects on cognitive functions (increased Repetition and Memory) than in the morning (increased Repetition), or the waiting-list control group (increased Judgment). Moreover, the program in the afternoon tended to reduce Anger-Hostility, and Fatigue. In conclusion, conducting the exercise program in the afternoon might be more effective for improving cognitive functions and the mood of older adults than in the morning. However, there was heterogeneity between the groups despite the randomization. Therefore, we suggest conducting a more rigorously controlled study using a larger sample to validate these findings.

Predictive Value of Localized Stenosis of the Main Pancreatic Duct for Early Detection of Pancreatic Cancer

Background/Aims:

In this study, we aimed to evaluate the predictive value of localized stenosis of the main pancreatic duct (MPD) for early detection of pancreatic cancer.

Methods:

Among 689 patients who underwent endoscopic retrograde pancreatography from January 2008 to September 2018, 19 patients with MPD findings were enrolled. These patients showed findings for indicating suspicious pancreatic cancer at an early stage (FiCE); FiCE was defined as a single, localized stenosis in the MPD without a detectable mass (using any other imaging methods) and without other pancreatic diseases, such as definite chronic pancreatitis, intraductal papillary mucinous neoplasm, and autoimmune pancreatitis. Final diagnoses were established by examining resected specimens or through follow-up examinations after an interval of >5 years.

Results:

Among 19 patients with FiCE, 11 underwent surgical resection and 8 were evaluated after a >5-year observation period. The final diagnosis of the MPD stenosis was judged to be pancreatic cancer in 9 patients (47%), including 3 with intraepithelial cancer, and to be a non-neoplastic change in 10. The sensitivity, specificity, and accuracy of preoperative pancreatic juice cytology were 75%, 100%, and 88%, respectively.

Conclusions:

The predictive value of FiCE for pancreatic cancer prevalence was 47%. Histological confirmation with pancreatic juice cytology is necessary before surgical resection.

Endoscopic Ultrasonography-Guided Gallbladder Drainage as a Treatment Option for Acute Cholecystitis after Metal Stent Placement in Malignant Biliary Strictures

Background/Aims

It is often difficult to manage acute cholecystitis after metal stent (MS) placement in unresectable malignant biliary strictures. The aim of this study was to evaluate the feasibility of endoscopic ultrasonography-guided gallbladder drainage (EUS-GBD) for acute cholecystitis.

Methods

The clinical outcomes of 10 patients who underwent EUS-GBD for acute cholecystitis after MS placement between January 2011 and August 2018 were retrospectively evaluated. The procedural outcomes of percutaneous transhepatic gallbladder drainage (PTGBD) with tube placement (n=11 cases) and aspiration (PTGBA) (n=27 cases) during the study period were evaluated as a reference.

Results

The technical success and clinical effectiveness rates of EUS-GBD were 90% (9/10) and 89% (8/9), respectively. Severe bile leakage that required surgical treatment occurred in one case. Acute cholecystitis recurred after stent dislocation in 38% (3/8) of the cases. Both PTGBD and PTGBA were technically successful in all cases without severe adverse events and clinically effective in 91% and 63% of the cases, respectively.

Conclusions

EUS-GBD after MS placement was a feasible option for treating acute cholecystitis. However, it was a rescue technique following the established percutaneous intervention in the current setting because of the immature technical methodology, including dedicated devices, which need further development.

Predictive Factors for Inaccurate Diagnosis of Swollen Lymph Nodes in Endoscopic Ultrasound-Guided Fine Needle Aspiration

Background/Aims

This study aimed to identify the predictive factors for inaccurate endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) diagnosis of swollen lymph nodes without rapid on-site cytopathological evaluation.

Methods

Eighty-three consecutive patients who underwent EUS-FNA for abdominal or mediastinal lymph nodes from January 2008 to June 2017 were included from a prospectively maintained EUS-FNA database and retrospectively reviewed. The sensitivity, specificity, and accuracy of EUS-FNA for the detection of neoplastic diseases were calculated. Candidate factors for inaccurate diagnosis (lymph node size and location, needle type, puncture route, number of passes, and causative disease) were evaluated by comparison between accurately diagnosed cases and others.

Results

The final diagnosis of the punctured lymph node was classified as neoplastic (65 cases: a metastatic lymph node, malignant lymphoma, or Crow-Fukase syndrome) or non-neoplastic (18 cases: a reactive node or amyloidosis). The sensitivity, specificity, and accuracy were 83%, 94%, and 86%, respectively. On multivariate analyses, small size of the lymph node was the sole predictive factor for inaccurate EUS-FNA diagnosis with a significant difference (odds ratios, 19.8; 95% confidence intervals, 3.15–124; p=0.0015).

Conclusions

The lymph node size of <16 mm was the only independent factor associated with inaccurate EUS-FNA diagnosis of swollen lymph nodes.

Knee extensor muscular activity estimation during different walking patterns: flat normal and brisk walking, stair climbing

Preserving mobility, the ability to keep a correct posture and dynamic balance in order to walk properly, is fundamental to maintain autonomy in daily life. Based on the correlation between muscle groups and autonomy, previous research has suggested that maintaining muscular tone in knee extensors is critical. Continuous training of knee extensors during aging is therefore essential to maintain independence. In this work, it is hypothesized that it is possible to estimate knee extensor activity only from IMU data based on a simple lower limbs model. The accuracy of the knee extensor activity estimation algorithm has been tested using sEMG measurements as control data on three different walking patterns: normal walk, fast walk and stair climbing. Estimated knee torque area and measured muscular activity for each step were compared confirming a high estimation accuracy with a correlation efficient R=0.80. Moreover, muscular activity can be divided based on intensity in three groups of statistically significant difference confirmed by the Steel-Dwass method. Future works should test the usability of the algorithm for different walking patterns, and use the collected data and the refined algorithm to implement a smart resistive device to increase knee extensor exertion during each walking pattern to the level necessary for sufficient extensor training.

Peroral cholangioscopy by SpyGlass DS versus CHF-B260 for evaluation of the lateral spread of extrahepatic cholangiocarcinoma

Background and study aims  A newly developed peroral cholangioscopy (POCS) system, SpyGlassDS has high maneuverability. This study aimed to evaluate acceptability of the accuracy of SpyGlassDS accompanied by simultaneous POCS-guided biopsy compared with that of a traditional POCS scope, CHF-B260, to diagnose the lateral extent of extrahepatic cholangiocarcinoma (LEC). Patients and methods  Patients who underwent surgical resection after preoperative examinations to diagnose LEC were evaluated. POCS by CHF-B260 was performed if there was discrepancy between preceding fluoroscopy-guided biopsy findings and other examinations between January 2004 and September 2015 (group A, n = 56); and POCS plus POCS-guided mapping biopsy by SpyGlassDS was performed in all surgical candidates between October 2015 and December 2017 (group B, n = 20). The main outcome measure was the accuracy of overall preoperative diagnosis (OPD) of LEC defined based on all examinations, including POCS. Results  Accuracy of OPD for the liver side and the ampullary side was 93 % and 100 %, respectively, in group A, and 84 % and 100 %, respectively, in group B ( P  = 0.37 for the liver side; P , not available for the ampullary side). Diagnostic accuracy of simple optical evaluation by POCS for the liver side and the ampullary side was 83 % and 100 %, respectively, in group A, and 58 % and 88 %, respectively, in group B ( P  = 0.29 for the liver side; P  = 0.40 for the ampullary side). Conclusions  POCS by SpyGlassDS was found to be acceptable and could be a standard approach for diagnosis of LEC.

Immunohistochemical Analysis of Human Lung Cancers with Anti-ras p21 Monoclonal Antibodies

The expression of ras oncogene product p21 in human malignant pleurisy and primary lung cancer was studied immunocyto-histochemically with monoclonal antibodies (MoAbs) rp-28 and rp-35 against ras p21. In pleural effusion cells, cancer cells revealed more intensively positive reaction with MoAb rp-35 than with MoAb rp-28, especially in the plasma membrane, and no positive reaction was obtained in any kind of inflammation cells with the exception of faintly positive reaction in the cytoplasm of macrophages.

In primary lung cancers, well or moderately differentiated adenocarcinoma tissues showed higher reactivity with MoAb rp-28 than those of poorly differentiated adenocarcinoma or any other histological subtype of lung cancer. With MoAb rp-35, intensively positive reaction was obtained in most of cases with all different histological subtypes of lung cancer. The staining in cancer cells was usually localized intensively to the plasma membrane and weakly to the cytoplasm with both MoAbs. Normal bronchial epithelial and glandular tissues showed only cytoplasmic staining. These two MoAbs, especially MoAb rp-35, may be useful in clinicopathological applications for the diagnosis of malignant pleurisy and primary lung cancer.