RESUMO
Durvalumab is the first immune check point inhibitor that was approved for use following concurrent platinum-based chemoradiation, in patients with unresectable stage III non-small cell lung cancer. The new treatment regimen of durvalumab administered after chemoradiation resulted in higher response rates and required careful immune-related adverse effects management. We experienced a rare case of severe acute kidney injury (AKI) requiring hemodialysis after only the first dose of durvalumab, in a patient who was diagnosed with immune-related AKI by renal biopsy. Although severe (Grade 3 or more) immune-related AKI occurred in 0.9% of patients treated with durvalumab, some drugs and radiation may increase immune-related AKI. Further research is needed to identify the clinical characteristics of patients who tend to develop severe AKI so as to prevent it, by reviewing such rare cases as ours.
Assuntos
Injúria Renal Aguda , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Quimiorradioterapia/efeitos adversos , Diálise RenalRESUMO
BACKGROUND: Oxaliplatin is an anticancer therapy for pancreatic, gastric, and colorectal cancers. It is also used in patients with carcinomas of unknown primary sites. Oxaliplatin is associated with less frequent renal dysfunction than other conventional platinum-based drugs such as cisplatin. Albeit, there have been several reports of acute kidney injury with frequent use. In all cases, renal dysfunction was temporary and did not require maintenance dialysis. There have been no previous reports of irreversible renal dysfunction after a single dose of oxaliplatin. CASE PRESENTATION: Previous reports of oxaliplatin-induced renal injury occurred after patients received multiples doses. In this study, a 75-year-old male with unknown primary cancer and underlying chronic kidney disease developed acute renal failure after receiving the first dose of oxaliplatin. Suspected of having drug-induced renal failure through an immunological mechanism, the patient was treated with steroids; however, treatment was ineffective. Renal biopsy ruled out interstitial nephritis and revealed acute tubular necrosis. Renal failure was irreversible, and the patient subsequently required maintenance hemodialysis. CONCLUSIONS: We provide the first report of pathology-confirmed acute tubular necrosis after the first dose of oxaliplatin which led to irreversible renal dysfunction and maintenance dialysis.
Assuntos
Injúria Renal Aguda , Falência Renal Crônica , Necrose Tubular Aguda , Neoplasias Primárias Desconhecidas , Nefrite Intersticial , Masculino , Humanos , Idoso , Oxaliplatina/efeitos adversos , Neoplasias Primárias Desconhecidas/complicações , Diálise Renal/efeitos adversos , Falência Renal Crônica/complicações , Necrose Tubular Aguda/induzido quimicamente , Necrose Tubular Aguda/diagnóstico , Nefrite Intersticial/induzido quimicamente , Nefrite Intersticial/diagnóstico , Nefrite Intersticial/complicações , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/terapia , Biópsia/efeitos adversos , NecroseRESUMO
The patient was a 70-year-old man who underwent transurethral resection of a bladder tumor. The pathological diagnosis was urothelial carcinoma (UC) with sarcomatoid variant, â§pT2. After neoadjuvant chemotherapy using gemcitabine and cisplatin (GC), radical cystectomy was performed. The histopathological diagnosis was no tumor remnant (ypT0ypN0). Seven months later, the patient underwent an emergency partial ileectomy for ileal occlusion, after sudden complaints of vomiting and abdominal pain and fullness. Postoperatively, two cycles of adjuvant GC chemotherapy were administered. Approximately 10 months after ileal metastasis, a mesenteric tumor appeared. After seven cycles of methotrexate/epirubicin/nedaplatin and 32 cycles of pembrolizumab therapy, the mesentery was resected. The pathological diagnosis was UC with sarcomatoid variant. No recurrence was noted for 2 years after resection of the mesentery.
Assuntos
Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Masculino , Humanos , Idoso , Neoplasias da Bexiga Urinária/cirurgia , Íleo , Terapia Neoadjuvante , Quimioterapia AdjuvanteRESUMO
Nevi are benign melanocytic tumors, and some nevi are considered to develop into malignant melanomas. Most nevi arise in the skin, but nevi occasionally occur in the conjunctiva, esophageal mucosa, or at other sites. Pulmonary melanocytic nevi are extremely rare, and only one case has been reported in the literature. Here, we present a case of pulmonary melanocytic nevus, involving a BRAF gene mutation (V600E), and we discuss the potential significance of this condition as a precursor to pulmonary malignant melanoma.
Assuntos
Neoplasias Pulmonares/genética , Nevo Pigmentado/genética , Proteínas Proto-Oncogênicas B-raf/genética , Análise Mutacional de DNA , Feminino , Humanos , Neoplasias Pulmonares/patologia , Pessoa de Meia-Idade , Mutação , Nevo Pigmentado/patologiaRESUMO
The expression of microRNA-31 (miR-31) has been implicated in the progression of some human malignancies including colorectal cancer. However, the clinical significance of the expression of miR-31 in submucosally invasive (T1) colorectal cancer remains unclear. The aim of the present study was to delineate the relationship between clinicopathological features and the oncogenic modulator miR-31 in submucosally invasive colorectal cancer. We investigated the expression of miR-31 in 50 submucosally invasive colorectal cancer specimens, along with the corresponding non-tumoral mucosa specimens, using a real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The relationships between miR-31 expression levels and clinicopathological characteristics were assessed. The miR-31 host gene locus was investigated using fluorescence in situ hybridization. qRT-PCR revealed that the expression of miR-31 was higher in colorectal cancer tissue than in non-tumoral tissue (P = 0.0002). The up-regulated expression of miR-31 may play an oncogenic role in the early stage of carcinogenesis in colorectal cancers.
Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação Neoplásica da Expressão Gênica/genética , MicroRNAs/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Neoplasias Colorretais/diagnóstico , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodosRESUMO
In adenocarcinoma of the small intestine, delays in diagnosis are frequent. The majority of patients present with advancedstage disease, and have either lymph node involvement or distant metastatic disease. Surgical resection is a mainstay in treatment of this disease, and the effectiveness of chemotherapy for advanced-stage or metastatic disease has been reported. We report a case of adenocarcinoma of the small intestine surviving for many years after surgical resection and chemotherapy. A 47-year-old woman underwent a small intestine resection, because she had a small intestinal tumor with obstruction. Histopathological examination revealed moderately-differentiated adenocarcinoma with lymph node metastasis. Adjuvant chemotherapy with S-1 was administered for a year, but in March 2006, a recurrent lesion at the right ovary was detected, and she underwent right adnexectomy. Because the ascites cytology revealed class V, chemotherapy was administered. In December 2008, CA19-9 elevated and magnetic resonance imaging showed a tumor behind the uterus, which was diagnosed as a recurrent disease. Because the tumor invaded the rectum, she received a low anterior resection, hysterectomy, and left adnexectomy. After surgical resection, UFT/UZEL was administered for half a year. In July 2010, computed tomography showed multiple lung metastases, and chemotherapy was performed again. However, the regimen was changed because her tumor marker elevated. She is being treated using a combination of cisplatin and irinotecan.
Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Intestinais/tratamento farmacológico , Adenocarcinoma/secundário , Adenocarcinoma/cirurgia , Terapia Combinada , Feminino , Humanos , Neoplasias Intestinais/patologia , Neoplasias Intestinais/cirurgia , Metástase Linfática , Pessoa de Meia-Idade , Neoplasias Retroperitoneais/tratamento farmacológico , Neoplasias Retroperitoneais/secundário , Fatores de TempoRESUMO
Coronavirus disease 2019 (COVID-19) is a severe respiratory infection that can be fatal in unvaccinated individuals; however, acute kidney injury (AKI) is a rare adverse reaction to COVID-19 vaccination. AKI resulting from multiple conditions can have severe consequences, including end-stage renal failure, if not treated with immunosuppressive agents. However, acute tubular injury (ATI) as the sole cause of AKI has not been previously reported. Herein, we discuss an obese 54-year-old man with type 2 diabetes who received four COVID-19 vaccines; three from Pfizer and one from Moderna. Diabetic retinopathy, urinary protein, and occult blood were absent with no other underlying diseases. There was no history of COVID-19 infection. He was referred to our hospital 5 days after receiving the fourth Pfizer-BioNTech COVID-19 vaccine dose with stage 3 AKI. Urinary findings revealed new proteinuria and glomerular occult blood. Physical examination and infection testing were unremarkable. Steroids were introduced on admission for rapidly progressive glomerulonephritis. A renal biopsy performed on Day 2 revealed only ATI. Therefore, steroids were discontinued on Day 5, after which renal function recovered spontaneously, and urinalysis abnormalities disappeared. Renal function remained normal during follow-up. We report a case of AKI with severe renal dysfunction after COVID-19 vaccination, wherein renal biopsy effectively determined the disease status (ATI), which did not require immunosuppressive treatment.
RESUMO
BACKGROUND: Primary malignant melanoma of the lung (PML) is extremely rare. No precursor lesions of PML have been identified, and little is known about the genetic mutations associated with the disease. Typically, 15-20% of malignant melanomas possess NRAS gene mutations, but no cases of NRAS-mutated PML have been reported in the English literature. We present a case of PML involving an NRAS mutation. CASE PRESENTATION: Clinical summary A 74-year-old Japanese female presented with worsening dyspnea and was admitted to hospital. Computed tomography (CT) revealed a right lung (S10) mass and pleural dissemination. Cytology of the pleural effusion in the right lung was performed, and malignant melanoma or clear cell sarcoma was suspected. A dermatological examination and gallium scintigraphy were conducted to determine the primary tumor site, but no suspicious lesions, expect for the right lung mass, were found. After admission, CT showed complicating bilateral pneumonia, and an antibiotic drug was administered, but the pleural effusion got worse. About 2 weeks later, the patient died of respiratory failure and cardiac arrest. An autopsy was performed to determine the histological diagnosis. Autopsy findings A 26x15x20-mm black and pale yellow mass was found in the right lower lobe. Many disseminated nodules were found in the right lobe. The tumor had invaded the right diaphragm. Subcarinal lymph node metastasis was also detected. Immunohistochemically, the tumor cells exhibited positivity for S-100 and HMB45 staining. The patient was diagnosed with malignant melanoma. Sanger sequencing of the tumor detected an NRAS mutation. CONCLUSIONS: We found an NRAS D54N mutation in PML, which has not been reported previously anywhere in the world. Previous reports indicated that most cases of PML can be classified into the triple-wild-type, but BRAF mutation status was only analyzed in a few cases. We should analyze the mutation patterns of PML to determine whether any subtypes other than the triple-wild-type exist. PML might be a form of de novo cancer.
Assuntos
GTP Fosfo-Hidrolases/genética , Neoplasias Pulmonares/genética , Melanoma/genética , Proteínas de Membrana/genética , Mutação/genética , Proteínas Proto-Oncogênicas B-raf/genética , Idoso , Feminino , Humanos , Melanoma/diagnóstico , Melanoma/patologiaRESUMO
Pathological characteristics, patient outcome, and preoperative examinations of 16 cases (4.1%) of chromophobe renal cell carcinoma (RCC) observed among 389 patients with RCC treated at Yokohama City University Hospital and Yokohama City University Medical Center between 1991 and 2004 were analyzed. The age distribution was 16 to 74 years old (average age; 50.9 +/- 17.0). Pathologically, 14 patients had pure chromophobe RCC, and two patients had chromophobe RCC coexisting with aggressive pathological elements, that is, sarcomatoid change in one patient and collecting duct carcinoma in the other. The average tumor size was 7.1 +/- 4.1 cm. On preoperative imaging studies with enhanced computed tomography or angiography, all cases showed a hypovascular pattern. C-reactive protein (CRP) and immunosuppressive acidic protein (IAP) were increased specifically in the two cases coexisting with aggressive pathological elements. Fourteen cases showing pure chromophobe RCC did not metastases on preoperative examination. Thirteen cases were treated by nephrectomy, and another was treated by partial nephrectomy. To date there have been no recurrences during the 6 to 160 months postoperative follow-up. The patient with a mixture of chromophobe RCC and sarcomatoid change (pT3aN0M0) died of multiple lung metastases 18 months after nephrectomy. The patient showing a mixture of chromophobe RCC and collecting duct carcinoma demonstrated metastases to the paraaortic lymph nodes at preoperative examination (pT1bN2M0), and died of multiple lung and bone metastases and carcinomatous peritonitis 8 months after nephrectomy. The patients with pure chromophobe RCC had a favorable prognosis, but those with a mixed type including aggressive elements such as sarcomatoid change or collecting duct carcinoma, showed a poor clinical course. The increase in CRP or IAP could predict poor prognosis in such cases.
Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Nefrectomia , Adolescente , Adulto , Idoso , Neoplasias Ósseas/secundário , Carcinoma de Células Renais/secundário , Carcinoma de Células Renais/cirurgia , Feminino , Humanos , Neoplasias Renais/cirurgia , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do TratamentoRESUMO
A 37-year-old man was admitted to our hospital because of suspicion of the lung cancer in November 2003. Transbronchial tumor biopsy revealed a small number of tumor cells with rhabdoid features, which had eosinophilic cytoplasmic globules. However, a definitive histological diagnosis was not obtained. We considered that a diagnosis of lung malignant tumor was likely according to the findings of chest CT scan and pathology. Although radiotherapy reduced the tumor size, he started to have abdominal pain and tarry stool one month after radio therapy. Multiple small intestine metastases were detected by gastroenterological endoscopy. The patient died due to bleeding from these metastatic lesions in May 2004. Immunohistologic staining of the cervical lymph node showed that rhabdoid cells were positive for epithelial membrane antigen (EMA), vimentin, and anticytokeratin antibody (CAM5.2), but not for thyroid transcription factor-1 (TTF-1). From the autopsy findings and clinical course, he was finally diagnosed with large cell carcinoma of the lung with rhabdoid phenotype. Because of its aggressive clinical course, early diagnosis and decision on therapy would be very important for this disease.
Assuntos
Carcinoma de Células Grandes/patologia , Neoplasias Pulmonares/patologia , Neoplasias Primárias Múltiplas/patologia , Tumor Rabdoide/patologia , Adulto , Carcinoma de Células Grandes/diagnóstico por imagem , Carcinoma de Células Grandes/secundário , Neoplasias Duodenais/secundário , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Fenótipo , Tomografia Computadorizada por Raios XRESUMO
Interdigitating dendritic cell sarcoma is an extremely rare neoplasm that mainly occurs in the lymph nodes. We report a case of interdigitating dendritic cell sarcoma arising from the spleen, a previously unreported site for interdigitating dendritic cell sarcoma. An 87-year-old woman, visiting Ashigara Hospital with complaints of palpitation and dyspnea, was found to have pancytopenia and low proteinemia. Abdominal ultrasonography and CT scanning demonstrated severe splenomegaly with heterogeneous enhancement. She received a splenectomy under the clinical diagnosis of a splenic tumor. Grossly, the spleen was markedly enlarged, with confluent massive nodules. Microscopically, the normal architecture was effaced with diffuse proliferation of large pleomorphic cells arrayed in a somewhat sheet-like pattern. Erythrophagocytosis was commonly observed. Immunohistochemical studies showed that the tumor cells were positive for S-100 protein, fascin, vimentin, and CD68, but uniformly negative for CD45, B- and T-cell markers, CD1a, CD30, complement receptors, CD34, Factor VIII, HMB-45, and lysozyme. Ultrastructurally, the tumor cells possessed complex interdigitating cytoplasmic dendritic processes. Birbeck granules were absent. Based on these findings, the present case was diagnosed as interdigitating dendritic cell sarcoma. The patient died of multiple liver metastases 3 months postoperatively.
Assuntos
Sarcoma/patologia , Neoplasias Esplênicas/patologia , Idoso , Idoso de 80 Anos ou mais , Células Dendríticas/patologia , Eritrócitos/fisiologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Microscopia Eletrônica , Fagocitose , Sarcoma/química , Sarcoma/ultraestrutura , Neoplasias Esplênicas/química , Neoplasias Esplênicas/ultraestruturaRESUMO
OBJECTIVE: To apply the polymerase chain reaction (PCR) to detect clonality for potentially helping to establish a definitive diagnosis of lymphoma in cytologic material. STUDY DESIGN: In this retrospective study, Papanicolaou-stained cytologic smears and formalin-fixed, paraffin-embedded tissues from 17 cases of B-cell lymphoma were examined to investigate their clonality by a PCR technique using three different approaches (FR3, FR3A and FR2) for amplification of immunoglobulin heavy chain genes. Cytologic smears from 10 cases of nonneoplastic lymphoid tissues and T-cell lymphomas served as negative controls. RESULTS: Monoclonality was detected in 9 of 17 cases (53%) of B-cell lymphoma in cytologic smears as compared with 8 of 16 cases (50%) in tissue sections. Semi-nested PCRs (FR3A/FR2) were superior to the single PCR (FR3) in the detection rate (41% vs. 18%). Five of seven cases (71%) of marginal zone B-cell lymphomas showed monoclonality, whereas only 4 of 10 cases (40%) of diffuse large B-cell lymphomas did so. Monoclonality was demonstrated in none of the negative controls. CONCLUSIONS: Clonality detection in B-cell lymphomas by PCR using cytologic smears is specific and equal in sensitivity to that using formalin-fixed, paraffin-embedded tissues. The detection rate is especially excellent in marginal zone B-cell lymphoma, in which the cytologic diagnosis is particularly challenging. Combined seminested PCRs for FR3A and FR2 are advocated for a reliable assessment of clonality.
Assuntos
Linfoma de Células B/diagnóstico , Biópsia , Diferenciação Celular , DNA de Neoplasias/análise , DNA de Neoplasias/genética , Humanos , Linfoma de Células B/genética , Linfoma de Células B/patologia , Reação em Cadeia da Polimerase/métodos , Estudos RetrospectivosAssuntos
Malformações Arteriovenosas/complicações , Hipertensão Portal/etiologia , Artérias Mesentéricas/anormalidades , Veias Mesentéricas/anormalidades , Idoso , Malformações Arteriovenosas/cirurgia , Líquido Ascítico/etiologia , Líquido Ascítico/cirurgia , Varizes Esofágicas e Gástricas/etiologia , Varizes Esofágicas e Gástricas/cirurgia , Humanos , Hipertensão Portal/cirurgia , Ileostomia , Íleo/irrigação sanguínea , Masculino , Resultado do TratamentoAssuntos
Adenocarcinoma/parasitologia , Carcinoma Adenoescamoso/parasitologia , Clonorquíase/complicações , Clonorchis sinensis , Neoplasias do Ducto Colédoco/parasitologia , Neoplasias Primárias Múltiplas , Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Idoso , Animais , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/cirurgia , Neoplasias do Ducto Colédoco/patologia , Neoplasias do Ducto Colédoco/cirurgia , Humanos , MasculinoRESUMO
Chromophobe renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) are derived from the collecting duct epithelia, although their morphology, molecular biologic characteristics and clinical behaviors are quite different. Herein is presented a case of RCC possessing the chromophobe RCC and CDC elements occurring in a 64 year-old Japanese woman. The patient was referred to Yokohama City University Hospital with complaints of persistent back pain and fever. Radiologic examinations revealed a left renal tumor, and radical nephrectomy was performed. The patient died with multiple metastases, 8 months after the operation. The resected tumor showed an invasive growth, and its cut surface was heterogenous with hemorrhage and necrosis. Histologically, the tumor was composed of chromophobe elements with dedifferentiation, and CDC elements. The chromophobe and CDC elements had obvious histological transition. Lectin histochemistry and immunohistochemistry confirmed that this tumor was derived from the distal nephron. c-KIT, p53 and Ki67 antigen showed differential localization between the chromophobe and CDC elements, even in the transitional areas. Along with the previous reports, the present case seemed to be composite RCC derived from the collecting duct, which might present clues to elucidate carcinogenesis in the distal nephron.
Assuntos
Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Túbulos Renais Coletores/patologia , Néfrons/patologia , Carcinoma de Células Renais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Antígeno Ki-67/análise , Neoplasias Renais/metabolismo , Túbulos Renais Coletores/química , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/análise , Proteína Supressora de Tumor p53/análiseRESUMO
A 33-year-old man with an intramedullary spinal cord germinoma was treated successfully with partial resection, combined chemotherapy with carboplatin and etoposide, and reduced-dose local-field radiation therapy. The authors believe this is the first case without syncytiotrophoblastic giant cells so treated. The literature is reviewed, and the appearance, radiologic and histopathologic features, and treatment of germinomas are discussed.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Germinoma/terapia , Neoplasias da Medula Espinal/terapia , Adulto , Terapia Combinada , Diagnóstico Diferencial , Germinoma/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Dosagem Radioterapêutica , Neoplasias da Medula Espinal/patologiaRESUMO
We report a 35-year-old woman with locally advanced mucinous carcinoma of the breast with sudden growth acceleration. A pea-sized mass developed into an ulcerated large tumor within 1 month. After the combination of chemotherapy, radiation and hyperthermia, a radical mastectomy was performed, followed by repair of the skin defect by latissimus dorsi and rectus abdominis musculocutaneous flaps. Histological examination revealed a pure mucinous carcinoma with axillary lymph node involvement. Estrogen and progesterone receptors were not detected in the tumor. Twenty-five months after treatment, there is no sign of recurrent disease. Pure mucinous carcinoma generally has a less aggressive growth pattern as defined by tumor size, adherence to the overlying skin/bottom fasciae, estrogen and progesterone receptor positive and primary lymph axillary lymph node metastases. This case showed completely opposite features to all of these typical biological features of pure mucinous carcinomas.
Assuntos
Adenocarcinoma Mucinoso/terapia , Neoplasias da Mama/terapia , Mastectomia Radical , Adenocarcinoma Mucinoso/patologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/patologia , Terapia Combinada , Progressão da Doença , Doxorrubicina/administração & dosagem , Doxorrubicina/análogos & derivados , Feminino , Humanos , Paclitaxel/administração & dosagem , Dosagem RadioterapêuticaRESUMO
The salient histopathologic features of low-grade adenocarcinoma of the fetal lung type (L-FLAC)/well-differentiated fetal adenocarcinoma (WDFA) include complex glandular structures and morules with biotin-rich optically clear nuclei. Interestingly, these characteristic features are shared by the cribriform-morular variant of papillary thyroid carcinoma, whose morphology is identical to that of familial adenomatous polyposis (FAP)-associated thyroid carcinoma. Furthermore, the single reported case of lung cancer associated with FAP was L-FLAC/WDFA. These observations lead us to hypothesize that up-regulation of the Wnt signaling pathway underlies the development of L-FLAC/WDFA. To verify this hypothesis, 11 cases of L-FLAC/WDFA, including the one FAP-associated case, eight cases of high-grade adenocarcinoma of the fetal lung type (H-FLAC), 24 cases of conventional pulmonary adenocarcinoma (CAC), and 13 fetal lungs were immunostained for beta-catenin. All cases of L-FLAC/WDFA showed predominantly aberrant nuclear/cytoplasmic expression, especially in budding glands and morules, whereas six of eight cases (75%) of H-FLAC and all but one case (96%) of CAC showed predominantly membranous expression. Fetal lungs showed nuclear/cytoplasmic expression restricted to the distal branching airway epithelium. Mutational analysis of exon 3 of the beta-catenin gene in five sporadic cases of L-FLAC/WDFA showed a point mutation at codon 34 and codon 37 in two cases, respectively. The present study indicates that up-regulating disturbances in the Wnt signaling pathway, including mutation of the beta-catenin gene, underlie tumorigenesis of L-FLAC/WDFA. The expression pattern of beta-catenin in L-FLAC/WDFA resembles that of the developing fetal lung airway. With the expression pattern of beta-catenin as a marker, most cases of H-FLAC as well as CAC appear to have different oncogenic pathways from cases of L-FLAC/WDFA. The present study together with other available data also suggests that abnormal up-regulation of the Wnt signaling pathway may be a common denominator for the development of tumors with morular formation from a variety of anatomic sites.