A diagnostically challenging case of inflammatory myofibroblastic tumor primary to the peritoneum.

Introduction: Inflammatory myofibroblastic tumors are difficult to diagnose because of the lack of specific indicators. We describe a diagnostically challenging case of an inflammatory myofibroblastic tumor primary to the peritoneum. Case presentation: The patient was a 25-year-old male who presented at our hospital with lower abdominal pain. Computed tomography revealed a mass lesion 80 mm in diameter just above the bladder. This was suspected to be a bleeding tumor of the urachus. Since malignancy could not be ruled out, surgery was planned. This revealed a fragile tumor arising from the peritoneum. Following its removal, the tumor was diagnosed by histopathological analysis as an inflammatory myofibroblastic tumor. Conclusion: We describe a case of inflammatory myofibroblastic tumor primary to the peritoneum diagnosed by histopathology. Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of abdominal wall and anterior bladder tumors.

Drug-related pneumonitis caused by amikacin liposome inhalation suspension: One pathologically proven case and single-center experience.

Amikacin liposome inhalation suspension (ALIS) is known to cause drug-related pneumonitis, which has been described as "hypersensitivity pneumonitis (HP)". However, its clinical and pathological characteristics have never been reported. We retrospectively evaluated 18 patients treated with ALIS. Three (16.7%) patients developed HP-pattern pneumonitis on high-resolution computed tomography. Serum eosinophil counts were elevated up to above 1000/µL in these three patients, which decreased with ALIS discontinuation only. Of note, the specimen obtained by transbronchial lung cryobiopsy in one patient revealed a mild degree of lymphocyte and eosinophil infiltration. Rather, the findings of acute lung injury such as an edematous thickening of the alveolar walls, and an accumulation of foamy degenerative macrophages in the alveolar lumina was prominent. A pulmonary alveolar proteinosis reaction was also observed. HP-pattern pneumonitis due to ALIS may pathologically correspond to acute lung injury and a pulmonary alveolar proteinosis reaction despite increasing serum eosinophil counts.

Hypersensitivity pneumonitis with Paecilomyces as suspected inciting antigen.

A 73-year-old man visited our hospital for persistent cough. Chest high-resolution CT (HRCT) showed infiltration shadows in lower lobes and diffuse ground glass opacities in the upper lobes. Blood tests showed elevated white blood cell, C-reactive protein, surfactant protein D, and Krebs von den Lungen-6 levels. After an antigen avoidance test, his HRCT and blood test findings improved; we diagnosed him with hypersensitivity pneumonitis (HP). A culture of the rotting interior walls within his home revealed Paecilomyces, which we believe caused his HP. Given the few patients with Paecilomyces-induced HP, systematic approach was important to identify the inciting antigen.

Spontaneous regression of acute fibrinous organizing pneumonia induced by COVID-19 vaccination: A case report.

A 42-year-old woman visited our hospital with complaints of fever, muscle pain, and dyspnea one week after receiving the coronavirus disease 2019 (COVID-19) vaccine. Chest high-resolution computed tomography showed a patchy consolidation and ground-glass attenuation in the both lungs, consistent with acute interstitial pneumonia. Transbronchial lung cryobiopsy revealed organizing pneumonia with marked intra-alveolar fibrin, and pathologically diagnosed as acute fibrinous organizing pneumonia (AFOP). Other causative diseases such as dermatomyositis was clinically ruled out, and COVID-19 vaccine-induced AFOP was diagnosed. Physician should check the history of COVID-19 vaccination when encountering a case of AFOP with an unknown cause.

Favourable surgical outcomes for either second primary lung cancer or intrapulmonary metastasis after resection of non-small-cell lung cancer.

OBJECTIVES: Metachronous lung cancer arising after resection of non-small-cell lung cancer is either a second primary lung cancer (SPLC) or intrapulmonary metastasis (IPM) of the initial lung cancer; however, differential diagnosis is difficult. We evaluated the surgical outcomes of metachronous lung cancer in a combined population of patients with SPLC and IPM. METHODS: A retrospective study of 3534 consecutive patients with resected non-small-cell lung cancer between 1992 and 2016 was conducted at 4 institutions. RESULTS: A total of 105 patients (66 males; median age, 70 years) who underwent a second pulmonary resection for metachronous lung cancer were included. Most patients (81%) underwent sublobar resection, and there was no 30-day mortality. All metachronous lung cancers were cN0, 5 were pN1-2. The postoperative comprehensive histologic assessment revealed SPLC (n = 77) and IPM (n = 28). The 5-year overall survival rate after the second resection was 70.6% (median follow-up: 69.7 months). A multivariable analysis showed that age >70 years at the second resection (P = 0.013), male sex (P = 0.003), lymph node involvement in metachronous cancer (P < 0.001), pathological invasive size of metachronous cancer >15 mm (P < 0.001) and overlapping squamous cell carcinoma histology of the initial and metachronous cancers (P = 0.003) were significant prognostic factors for poor survival after the second resection, whereas histological IPM was not (P = 0.065). CONCLUSIONS: Surgery for cN0 metachronous lung cancer is safe and shows good outcomes. There were no statistically significant differences in the SPLC and IPM results. Caution should be exercised when operating on patients with overlapping squamous cell carcinoma.

Concordance between transbronchial lung cryobiopsy and surgical lung biopsy in patients with idiopathic multicentric Castleman disease: A report of four cases.

BACKGROUND: Idiopathic multicentric Castleman disease (iMCD) is a rare polyclonal lymphoproliferative disease often associated with pulmonary involvement. Recently, transbronchial lung cryobiopsy (TBLC) has been reported to be useful for the diagnosis of diffuse interstitial lung disease. However, there have been no reports of pathological assessment of TBLC for iMCD. METHOD: To clarify the efficacy of TBLC in the diagnosis of iMCD, we retrospectively reviewed four iMCD patients who had undergone both TBLC and surgical lung biopsy (SLB). RESULTS: The median age was 44 years; 2 males and 2 females. Two or three TBLC specimens were taken from each patient. All patients had no complications other than minimal bleeding. The size of the TBLC specimens was approximately 5-6 × 3-4 mm, and the alveolar region, and centrilobular and perilobular areas were adequately sampled. As with SLB, the extent of lung lesions and inflammatory cell infiltration could be sufficiently evaluated by TBLC. The presence of lymphoid follicles could also be assessed by TBLC; however, the germinal centers with lymphoid follicles were difficult to evaluate. The TBLC specimens could also be evaluated for immunostaining, especially IgG4 immunostaining, to rule out IgG4-related lung disease. Pulmonary pathological grading showed a high concordance rate between major pathological findings of TBLC and SLB. The pathologist's confidence level of TBLC for the diagnosis of iMCD was high in all cases. CONCLUSIONS: TBLC exhibits a high concordance rate with SLB in the pathological evaluation of iMCD, which may be useful for the diagnosis of iMCD.

Comparison of the slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration for next-generation sequencing-compatible tissue collection in non-small cell lung cancer.

BACKGROUND: Personalized treatment for non-small cell lung cancer (NSCLC) has advanced rapidly, and elucidating the genetic changes that trigger this disease is crucial for appropriate treatment selection. Both slow-pull and aspiration methods of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) are accepted methods for collecting samples suitable for next-generation sequencing (NGS) to examine driver gene mutations and translocations in NSCLC. Here, we aimed to determine which of these two methods is superior for obtaining higher-quality samples from patients with NSCLC. METHODS: Seventy-one patients diagnosed with NSCLC via EBUS-TBNA using the slow-pull or aspiration (20-mL negative pressure) methods between July 2019 and September 2022 were included. A total of 203 tissue samples from the 71 patients were fixed in formalin, embedded in paraffin, and mounted on slides. The presence of tissue cores, degree of blood contamination, and number of tumor cells were compared between the groups. The success rate of NGS, using Oncomine Dx Target Test Multi-CDx, was also compared between the groups. RESULTS: The slow-pull method was associated with a higher yield of tissue cores, lower degree of blood contamination, and higher number of tumor cells than the aspiration method. The success rate of the NGS was also significantly higher for the slow-pull group (95%) than for the aspiration group (68%). CONCLUSION: Overall, these findings suggest that the slow-pull method is a superior technique for EBUS-TBNA to obtain high-quality tissue samples for NGS. The slow-pull method may contribute to the identification of driver gene mutations and translocations and facilitate personalized treatment of NSCLC.

Primary tracheal small-cell carcinoma detected 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma: A case report.

Primary tracheal small-cell carcinoma is rare, and is often treated using small-cell lung cancer guidelines given that no standard treatment has been established for it. We report a patient in whom nodules appeared in the trachea and left main bronchus 11 months after surgery for pulmonary large-cell neuroendocrine carcinoma; a biopsy revealed small-cell carcinoma. Given the absence of malignant lesions elsewhere in the body, the lesions were diagnosed as primary tracheal small-cell carcinoma. Respiratory failure progressed rapidly owing to airway stenosis caused by the growing lesion, and the patient required nasal high-flow therapy. However, the lesions shrank a few days after commencing first-line chemotherapy, and his respiratory failure resolved. Accelerated hyperfractionated radiotherapy was administered in conjunction with the third course of chemotherapy, and the patient ultimately achieved a complete response. Although the lesions were initially suspected of being postoperative recurrence of pulmonary large-cell neuroendocrine carcinoma, the fact that the biopsy revealed them to be primary tracheal small-cell carcinoma indicates that intra-airway nodules that appear after lung cancer surgery may possibly be primary tracheal tumors.

[Diffuse large B-cell lymphoma complicated with pancreatic fistula and peritonitis following initial chemotherapy].

A 59-year-old-woman complained of weight loss and abdominal pain. A CT scan revealed a 20 cm large retroperitoneal mass, and she was diagnosed with diffuse large B-cell lymphoma via biopsy of the mass. After 75% CHP therapy, she developed an acute abdomen and CT revealed generalized peritonitis. Amylase in the ascites fluid was elevated, and infiltration into the pancreas was suspected on CT before treatment, suggesting a pancreatic fistula caused by tumor shrinkage. Enterobacteria were found in ascites fluid culture, suggesting a gastrointestinal perforation complication. The patient was refractory to treatment, and death was confirmed due to progression of the primary disease. The pathological autopsy revealed diffuse pancreatic infiltration, suggesting that the pancreatic fistula was caused by pancreatic injury. Pancreatic fistula is a known complication of surgical procedures but is rarely caused by tumor shrinkage due to chemotherapy. Since there is no preventive method for pancreatic injury caused by tumor shrinkage, early diagnosis and early treatment of pancreatic fistula are critical, and ascites fluid analysis, including amylase, was thought to be useful for the diagnosis.

Thymic atypical carcinoid tumors with elevated mitotic counts in a patient with multiple endocrine neoplasia: A case report.

Thymic neuroendocrine tumors associated with multiple endocrine neoplasia are only defined as carcinoid and are not associated with large-cell neuroendocrine carcinoma (LCNEC). We report the case of a multiple endocrine neoplasia type 1 patient with atypical carcinoid tumors with elevated mitotic counts (AC-h), an intermediate condition between carcinoid and LCNEC. A 27-year-old man underwent surgery for an anterior mediastinal mass and was diagnosed with thymic LCNEC. Fifteen years later, a mass appeared at the same site, which was determined to be a postoperative recurrence based on the pathological results of a needle biopsy and the clinical course. The patient's disease remained stable for 10 months on anti-programmed death-ligand 1 antibody and platinum-containing chemotherapy. The needle biopsy specimen was submitted for next-generation sequencing, which revealed a MEN1 gene mutation, and after further examination, a diagnosis of multiple endocrine neoplasia type 1 was made. A re-examination of the surgical specimen from 15 years prior showed that it corresponded to AC-h. Although thymic AC-h is classified as thymic LCNEC according to the current definition, our data suggests that a search for multiple endocrine neoplasia is warranted in such patients.

Prognostic impact of HNF4α expression in interstitial lung disease.

Pneumocyte injury is a crucial factor influencing the severity of interstitial lung disease (ILD). In this study, we investigated the potential of hepatocyte nuclear factor α (HNF4α) as an immunohistochemical marker to detect pneumocyte injury and as a prognostic marker. Surgical lung biopsy specimens were collected from 309 patients with different types of ILDs (61 idiopathic pulmonary fibrosis (IPF), 173 non-IPF, and 75 unclassifiable ILD). HNF4α expression were examined and the frequency of positive cells (per mm2 ) was calculated. HNF4α was strongly expressed in regenerating pneumocytes present on fibroblastic foci, Masson bodies/organizing alveoli. In the non-IPF and unclassifiable ILD groups, cases with high frequency expression showed significantly poorer outcome. Particularly, in the unclassifiable ILD group, the prognostic impact was more significant (death due to ILD, log-rank test, p < 0.0001), with a 10-year survival rate (hazard ratio 11.1, Wald test, p = 0.0003), as compared to the non-IPF group (log-rank test, p = 0.0269; hazard ratio 2.7, Wald test, p = 0.0334). Multivariable analysis focusing on the unclassifiable ILD group confirmed that the frequent HNF4α expression was an independent prognostic factor (hazard ratio 28.6; Wald test, p = 0.0033). Thus, HNF4α can be utilized as an immunohistochemical marker for pneumocyte injury and have prognostic impact particularly in unclassifiable ILD.

A functionally improved case of obstructive impairment caused by systemic lupus erythematosus.

Pulmonary lymphoproliferative diseases are often associated with collagen diseases. In addition to treatment of the primary disease, additional treatments may be considered depending on the pathology presented in the case. https://bit.ly/3vKqsls.

A Case of Retroperitoneal Ganglioneuroma Accidentally Discovered by Laparoscopic Right Adrenalectomy.

A 65-year-old man was referred to our hospital for his right adrenal adenoma. Adrenal vein blood sampling revealed primary hyperaldosteronism, and he was referred to our department for surgical resection of his right adenoma. During the operation, a small nodule was discovered in addition to the adrenal tumor. The pathological diagnosis of this nodule was ganglioneuroma. We herein report a rare case of ganglioneuroma incidentally discovered by laparoscopic right adrenalectomy.

Myoepithelioma-like tumor of the vulvar region showing infiltrative growth and harboring only a few estrogen receptor-positive cells: A case report.

Recently, a new entity "myoepithelioma-like tumor of the vulvar region (MELTVR)" was proposed as a rare mesenchymal neoplasm arising in vulvar regions of adult women. While MELTVRs morphologically resemble soft tissue myoepitheliomas and extraskeletal myxoid chondrosarcomas, they have a unique immunohistochemical profile (positive for epithelial membrane antigen and estrogen receptor, negative for S100 protein and glial fibrillary acidic protein, and loss of INI1/SMARCB1 expression), and lack EWSR1 and NR4A3 gene rearrangement, as seen by fluorescence in situ hybridization. MELTVRs are usually well-demarcated tumors, with no reports of extensive infiltrative growth. In the current report, we present an unusual case of MELTVR showing infiltrative growth and harboring only a few estrogen receptor-positive cells, which might indicate a variation in this rare tumor.

A molecular pathological study of four cases of ciliated muconodular papillary tumors of the lung.

Ciliated muconodular papillary tumors (CMPTs) are a recently categorized benign or low-grade malignant neoplasm that develops in the peripheral lung. Only about 40 cases have been reported to date, and the clinicopathological characteristics have yet to be defined in detail. Here, we present four cases of CMPTs with a focus on their immunohistochemical profiles and driver gene mutations. These tumors were a papillary proliferation of a mixture of ciliated, mucous, and basal cells located in the peripheral lung. Ciliated, mucous and basal cells were positive for TTF-1 when using the clone SPT24, but negative for HNF-4α. Basal cells were positive for p40. Mucous cells in some tumors were positive for MUC5AC and MUC6. The Ki-67 index was less than 5%, and strong expression of p53 was not detected. Three of the four tumors had a BRAF (V600E) driver mutation, an EGFR (del E746-T751/S752V) driver mutation, or driver mutations in both EGFR (E709G) and KRAS (G12V). These mutation types are rare for any histological type of lung cancer. The present results confirmed that CMPT is a neoplasm with immunohistochemical features and driver gene mutations that are distinct from those of common lung tumors.

Fluorescent Light-Guided Cystoscopy with 5-ALA Aids in Accurate Surgical Margin Detection for TURBO: A Case Report.

Recent studies have revealed that transurethral resection in one piece (TURBO) has several benefits over standard transurethral resection of bladder tumor (TUR-Bt), including a higher rate of containing the bladder muscle tissue and single-block resection. Five-aminolevulinic acid (5-ALA) was approved for the detection of bladder tumor treated with TUR-Bt. A 71-year-old male patient who received right nephroureterectomy developed bladder tumor recurrence on routine cystoscopy follow-up. We planned TURBO using fluorescent light-guided cystoscopy with 5-ALA. We herein report a case of bladder tumor successfully treated with TURBO using fluorescent light-guided cystoscopy with 5-ALA to detect the tumor surgical margin.

Succinate dehydrogenase B-deficient renal cell carcinoma: A case report with novel germline mutation.

Succinate dehydrogenase-deficient renal cell carcinoma (SDH-deficient RCC) is a newly introduced histological type of RCC, which is caused by loss of subunit genes of SDH. It is known to frequently demonstrate familial occurrence and be frequently associated with gastrointestinal stromal tumors and paraganglioma. To date, only 53 cases have been reported. Here, we present an additional case of SDH-deficient RCC occurring in a 40-year-old female. The tumor was histologically biphasic, consisting of tubular and solid architectures. The tumor cells possessed oval nuclei with small nucleoli, and an eosinophilic granular cytoplasm with occasional vacuoles. These cells completely lost the immunohistochemical expression of B subunit of SDH (SDHB). Consequently, the tumor was diagnosed as SDHB-deficient RCC. We identified a novel germ line mutation of the SDHB gene, and also confirmed a hemizygous deletion of the wild-type allele in the tumor cells. To define the pathological characteristics of SDH-deficient RCC, precise diagnosis and accumulation of more cases are required.

[Hyaline vascular-type Castleman disease of the pulmonary hilum that expanded during two years].

A 15-year-old asymptomatic girl had an abnormal shadow pointed out on a chest roentgenogram during a school medical health check. Her chest X-ray films showed a mass in the left pulmonary hilum that had increased in size during the past 2 years. Chest computed tomography (CT) showed a mass, which showed slight accumulation on FDG-PET in the left pulmonary hilum. Left lower lobectomy was performed for diagnosis, and the histopathological diagnosis was hyaline vascular-type Castleman disease. We report a case of hyaline vascular-type Castleman disease in the right pulmonary hilum which increased quite rapidly.

[A case of transcatheter coil embolization for pulmonary arteriovenous malformation complicated with hepatic arteriovenous malformation].

A 57-year-old woman in whom pulmonary arteriovenous malformation (PAVM) associated with hereditary hemorrhagic telangiectasia (HHT) had been diagnosed after a chest X-ray film showed an abnormal shadow at the age of 39. After diagnosis, she suffered two ischemic brain attacks, presumably caused by PAVM. She was admitted to our hospital for evaluation and treatment of PAVM on February 9, 2008. We confirmed two PAVMs in right S(3)a and left S(9)a by chest CT scan and angiography. In addition, abdominal CT revealed hepatic arteriovenous malformation (HAVM). HAVM were thought to increase venous return to the right heart, (which might cause pulmonary hypertension after the embolization of PAVMs), leading to right heart failure. In order to prevent neurological events in future, we performed an embolization of PAVM with individual coils at monthly intervals. Six months after the last embolization treatment, she showed no symptoms of right heart failure and the size of PAVMs decreased. It is considered important for a patient with PAVM associated with HHT to undergo a thorough examination for arteriovenous malformation in other organs, before coil embolization.

[A case of solitary splenic metastasis following operation for pulmonary pleomorphic carcinoma: detected at an early stage by FDG-PET].

A 58-year-old man was admitted our hospital. Chest computed tomography (CT) showed a nodular opacity in the left upper lobe and a swollen lymph node in the left hilar region. 18-fluorodeoxyglucose positron emission tomography (FDG-PET) showed abnormal uptakes in the same field. Since thoracoscopic lung biopsy revealed that the tumor was poorly differentiated adenocarcinoma, a left upper lobectomy and lymph node dissection were performed. Histological findings showed numerous spindle cells, thus it was diagnosed as pleomorphic carcinoma, pT2N1M0. After three months, a FDG-PET was performed, which detected a tiny lesion in the spleen. However an abdominal CT scan and ultrasonography (US) performed in the same period showed no abnormal findings. After about 2 months, a solitary low density area (5.0 cm) was seen in the spleen on an abdominal CT scan. We performed splenectomy under a diagnosis of a solitary splenic metastasis of the lung cancer. Pathological confirmation was obtained. Our findings demonstrated that whole-body scanning by FDG-PET was able to detect a rare postoperative splenic recurrence earlier than CT or US scan.