[Alveolar adenoma of the lung]. / Al'veolyarnaya adenoma legkogo.

Alveolar adenoma of the lung is a rare benign tumor first described in 1986. This article presents an observation of alveolar adenoma in a 72-year-old woman. Morphological and immunohistochemical methods of tumor diagnostics, issues of differential diagnosis are analyzed. The necessity of complex examination, including radiation methods, morphologic examination and immunohistochemical diagnostics to exclude other more dangerous diseases is shown.

Alveolar adenoma and coexisting atypical adenomatous hyperplasia: a case report and literature review.

Alveolar adenoma is a rare tumour of the lung. It is typically found in asymptomatic adults as a peripheral or subplerual nodule on imaging examination. Microscopically, the tumour is composed of admixture of epithelial and mesenchymal component in variable sized cystic or alveolar structures. The tumour shows a benign nature. There have been no reported recurrences or metastases. Malignant transformation of alveolar adenoma and coexisting with lung carcinoma have been rarely described. In this article, we report a case of an alveolar adenoma and coexisting atypical adenomatous hyperplasia. This case, contributing to the limited numbers of cases described to date, illustrates the importance of awareness on the possibility of alveolar adenoma being associated with lung carcinoma and its precursor lesions especially when diagnosed by small biopsy specimens.

Radiographic and Pathologic Manifestations of Uncommon and Rare Pulmonary Lesions.

Pulmonary opacities/nodules are common findings on computed tomography examinations, which may represent an underlying infections or malignancy. However, not every pulmonary nodule or opacity represents malignancy or infection. We present a pictorial essay illustrating common as well as obscure noninfectious, nonmalignant pulmonary lesions. Lesions discussed include organizing pneumonia, Langerhans cell histiocytosis, pulmonary amyloidosis, hyalinizing granuloma, tumourlet (benign localized neuroendocrine cell proliferations), atypical alveolar hyperplasia, inflammatory myofibroblastic tumour, papillary alveolar adenoma, plasma cell granuloma, juvenile xanthogranuloma, and sclerosing hemangiomas. We discuss the clinical presentation, prevalence, radiographic clues, pathology, and diagnostic pitfalls of these rare lesions.

Alveolar adenoma with a single cyst: A case report.

Alveolar adenoma is a rare and benign pulmonary tumor, which originates from type II pneumocytes and is often incidentally identified on radiographic images. Alveolar adenoma presents as a peripleural, solitary and cystic nodule in the lung and may mimic other types of lung tumors, thus rendering its differential diagnosis difficult. Alveolar adenoma is diagnosed based on histopathological and immunohistochemical analyses. The present study describes the case of a 50-year-old male patient with alveolar adenoma. He visited a local doctor ~3 years prior due to left chest pain. A chest computed tomography scan revealed a cystic lesion in segment 8 of the left lung. A nodular shadow appeared in the cyst and gradually increased in size; the patient was thus referred to the authors' hospital. The nodule was well-defined, solitary and solid; thus, lung cancer or aspergilloma were suspected. Thoracoscopic wedge resection was performed as diagnostic therapy. The frozen sections were non-diagnostic, and a pathological examination revealed an alveolar adenoma with no evidence of malignancy and a negative culture. The patient had a good post-operative course, with no sign of recurrence at the follow-up evaluation 46 months later. On the whole, alveolar adenoma is a rare, benign pulmonary tumor that is difficult to diagnose pre-operatively.

Lung carcinogenicity by whole body inhalation exposure to Anatase-type Nano-titanium Dioxide in rats.

To investigate the carcinogenicity of anatase-type nano-titanium dioxide (aNTiO2), F344/DuCrlCrlj rats were exposed to aNTiO2 aerosol at concentrations of 0, 0.5, 2, and 8 mg/m3. The rats were divided into 2 groups: carcinogenicity study groups were exposed for two years, and satellite study groups were exposed for one year followed by recovery for 1 day, 26 weeks, and 52 weeks after the end of exposure. In the carcinogenicity groups, bronchiolo-alveolar carcinomas were observed in two 8 mg/m3-exposed males, showing an increasing trend by Peto's test. However, this incidence was at the upper limit of JBRC's historical control data. Bronchiolo-alveolar adenomas were observed in 1, 2, 3, and 4 rats of the 0, 0.5, 2, and 8 mg/m3-exposed females and were not statistically significant. However, the incidence in the 8 mg/m3-exposed females exceeded JBRC's historical control data. Therefore, we conclude there is equivocal evidence for the carcinogenicity of aNTiO2 in rats. No lung tumors were observed in the satellite groups. Particle-induced non-neoplastic lesions (alveolar epithelial hyperplasia and focal fibrosis) were observed in exposed males and females in both the carcinogenicity and satellite groups. Increased lung weight and neutrophils of bronchoalveolar lavage fluid were observed in the 8 mg/m3-exposed carcinogenicity groups. The aNTiO2 deposited in the lungs of the satellite group rats was decreased at 26 weeks after the end of exposure compared to 1 day after the end of exposure. At 52 weeks after the end of exposure, the decreased level was the same at 26 weeks after the end of exposure.

Alveolar Adenoma With CD34 Diffusely Positive Stromal Cells: A Rare Case Report and Literature Review.

Alveolar adenoma (AA) is a rare type of pulmonary neoplasm showing proliferation of alveolar epithelium and septal mesenchyme. Clinically, AA is asymptomatic, benign, and usually diagnosed incidentally. Surgical excision is curative. The etiology of AA is controversial and the pathogenesis is unknown, but it is thought to stem from type II pneumocytes and fibroblasts or fibroblast-like cells. The stromal cells in AA may show rare staining for CD34. Diffuse CD34 positivity of the interstitial stromal cells has rarely been described and reviewed. Here, we report a case of AA with strong and diffuse CD34 staining in the stromal cells.

Alveolar Adenoma: A 20-Year Experience at a Western Balkan University Hospital and a Literature Review.

Alveolar adenoma is a rare benign lung tumor. We report 5 patients within a 20-year period diagnosed with this rare tumor and its clinical and histopathological features, in order to emphasize its significance in differential diagnosis of other lung tumors. Alveolar adenoma was more frequently diagnosed in female patients (80%). The patients ranged in age from 52 to 68. Eighty percent of the patients had symptoms like dyspnea, and shoulder or back pain. Three patients underwent a video-assisted thoracoscopic surgery, while 2 patients underwent a thoracotomy in order to remove the tumor. The tumor was localized within the right upper lobe, right lower lobe, and left lower lobe in 40%, 40%, and 20% of patients, respectively. The tumor size ranged from 14 to 30 mm. A frozen section finding of all 5 tumors reported that the lesion was benign. In all analyzed tumors, immunohistochemical analysis showed positive expression of TTF-1 and pankeratin in surface epithelial cells, and Vimentin positivity and TTF-1 and pankeratin negativity in round stromal cells. Alveolar adenoma should be carefully considered in the differential diagnosis of solitary pulmonary nodules. Complete surgical removal of the lesion is widely used in its primary management.

Enlarging pulmonary cyst: a rare form of alveolar adenoma.

BACKGROUND: Alveolar adenoma is a rare benign tumour, usually presenting as a peripherally located solid mass, sometimes mimicking malignancy. CASE PRESENTATION: A 37-year-old woman presented with chronic intermittent vague chest discomfort. The chest x-ray showed a simple cyst in the left lower lung field, and serial computed tomography (CT) over the following 2-year period showed rapid growth of the cyst, from 3.5 to 9.0 cm in diameter. The CT scan suggested bronchiolar communication, which was suspected to be the cause of growth, via check-valve mechanism. Thoracoscopic surgery was performed, and we found a thin-walled cyst in the lingular segment. Wedge resection was performed and the pathology was an unexpected alveolar adenoma which had grown on the terminal bronchiole, causing the alveolus to rupture and the cyst to grow. In 48 months of follow-up, there was no evidence of recurrence and the patient's symptoms resolved. CONCLUSIONS: Rapidly growing pulmonary cysts can lead to complications including rupture with pneumothorax and haemothorax, and surgery is always indicated. Abnormally rapid growth may indicate an underlying pathology such as alveolar adenoma. Surgical resection is the treatment of choice and there have been no reported cases of recurrence. Here we present a rare form of alveolar adenoma, which was a form of rapidly growing pulmonary cyst.

Rare benign lung tumours presenting with high clinical suspicion for malignancy: a case series and review of the literature.

INTRODUCTION: Incidentally discovered lung nodules can be worrisome for both the patient and their physicians. Although 95% of solitary lung nodules are benign, it is important to distinguish which nodules have high clinical suspicion for malignancy. Existing clinical guidelines do not apply to patients with signs and symptoms related to the lesion and with an increased baseline risk of lung cancer or metastasis. This paper highlights the vital role of pathohistological analysis and immunohistochemistry in the definitive diagnosis of such incidentally discovered lung nodules. MATERIAL AND METHODS: The three cases presented were selected based on their similar clinical presentations. A review of the literature was performed using the online database PubMed, for articles published in the period between January of 1973 to February of 2023 using the following medical subject headlines: "primary alveolar adenoma," "alveolar adenoma," "primary pulmonary meningioma," "pulmonary meningioma," and "pulmonary benign metastasizing leiomyoma." Results (Case Series). The case series consists of three incidentally discovered lung nodule(s). Although they presented with high clinical suspicion for malignancy, detailed workup confirmed the diagnosis of three rare benign lung tumours: primary alveolar adenoma, primary pulmonary meningioma, and benign metastasizing leiomyoma. CONCLUSIONS: Clinical suspicion for malignancy in the presented cases arose from previous and current medical history of malignancy, family history of malignancy, and/or specific radiographic findings. This paper highlights the need for a multidisciplinary approach in the management of incidentally discovered pulmonary nodules. Excisional biopsy and pathohistological analysis remain the gold standard in confirming the presence of a pathologic process and determining the nature of the disease. Common features of the diagnostic algorithm utilized among the three cases include multi-slice computerized tomography, excisional biopsy via atypical wedge resection (if the nodule is peripherally located), and lastly, pathomorphological analysis using haematoxylin and eosin staining and immunohistochemistry.

Pulmonary papillary adenoma with malignant potential: a case report and literature review.

BACKGROUND: Pulmonary papillary adenoma is a rare benign tumor in the periphery of the lung. We report a 66-year-old female patient with a tumor in the lower lobe of the right lung and present the clinicopathological features and review the literature. CASE PRESENTATION: A tumor in the lower lobe of the right lung was found incidentally on chest X-ray during the physical examination of the patient, and the patient occasionally had a dry cough that was not treated. The tumor was clearly demarcated and lobulated on CT scan. After 2 years of follow-up, the boundary of the tumor was still clear, with more lobulations and the enhanced scan showed uniform enhancement. Grossly, the tumor had a granular cut surface and was easy to fall off, which was helpful for the diagnosis of papillary adenoma during intraoperative frozen examination. Under the microscope, most areas of the tumor had the typical morphological structure of papillary adenoma. However, the tumor locally protruded into the surrounding lung tissue, accompanied by crowded cells and high cell proliferation index. It was suggested that this case of papillary adenoma had malignant potential and needed active intervention and treatment. CONCLUSION: Pulmonary papillary adenoma is a rare epithelial tumor with malignant potential. Surgical treatment should be performed as soon as possible after diagnosis to prevent malignant transformation.

Alveolar adenoma with poor imaging: a case report.

Alveolar adenoma is an isolated, well-defined peripheral lung tumor that originates from type II alveolar cells. The tumor consists of a network of simple, low-cubic, epithelium-coated lacunae with varying amounts of fine and inconspicuous-to-thick spindle cells that sometimes contain mucus sample matrix. Few cases of alveolar adenoma have been reported. These tumors are usually detected by imaging examinations where the alveolar adenoma typically presents as a peripheral, solitary cystic nodule in the lung. The presentation may mimic that of other types of lung tumors, consequently leading to difficulties in the differential diagnosis of this condition. Thus, accurate diagnosis of alveolar adenoma is based on a combination of pathological sections and immunohistochemistry. This study describes an alveolar adenoma in a 59-year-old female patient. Chest X-ray imaging and chest computed tomography identified malignant lesions in the right upper lobe. The patient subsequently underwent a thoracoscopic right upper lobectomy. The diagnosis of alveolar adenoma was confirmed after pathological examination of the excised postoperative tissue. The disease course was stable, and there was no recurrence of pulmonary lesions during 3 years of postoperative patient follow-up. Herein, we report the case of a patient with benign alveolar adenoma with poor imaging and pathological results.

Massive Relief: Papillary Adenoma of the Lung in Asymptomatic Former Smoker Patient.

Benign epithelial tumors of the lung are uncommon and can represent a diagnostic challenge. Herein, we describe one such emblematic case. A 59-year-old former smoker male was admitted to the hospital complaining of cough for a long time. A radiological examination showed a centrally excavated mass strictly connected to the visceral pleura. The patient underwent tumorectomy. At gross examination, the tumor was composed of solid and cystic areas containing clear liquid. Histological examination highlighted a sub-pleural encapsulated tumor, with foci of capsular invasion, characterized by a single layer of columnar and cuboidal epithelial cells lining moderately cellular fibro-vascular cores. A wide spectrum of immunohistochemical markers was performed. The final diagnosis was suggestive of a peripheral pulmonary papillary tumor of undetermined malignant potential. At the last follow-up, six years after surgery, no recurrence or metastases were described. Reporting this case, we would like to point out the existence of these rare entities that should be taken into account in the diagnostic process, thus avoiding potential misdiagnosis. Moreover, the presence of capsular invasion should be better investigated in order to reconsider the exact terminology of the tumor and the classification of its malignant potential.

Malignant transformation of alveolar adenoma to papillary adenocarcinoma: a case report.

We present a case involving alveolar adenoma (AA) comprising a malignant component. An 83-year-old man was referred with a solitary pulmonary nodule, which was diagnosed as adenocarcinoma (AC) by transbronchial biopsy. Resected specimen after left S1+2 segmentectomy revealed that the tumor comprised two histologically distinct areas-a central multi-cystic area (AA) and a surrounding area (papillary AC). Careful examination clarified that the borderline lesion showed intermediate mindbomb homolog-1 index and cytological atypia with low papillary growth, suggesting the possibility of malignant transformation of the AA. The malignant potential and coexisting lung carcinoma should be considered in evaluating the tumor diagnosed as AA.

Coexistence of lung alveolar adenoma with cerebral arteriovenous malformations: A case report and literature review.

Alveolar adenoma is an extremely rare benign tumor of the lung derived from type II pneumocytes. To date, only a limited number of alveolar adenoma cases have been reported in the literature. These tumors are usually discovered incidentally on radiographic images. However, other tumor types must be excluded when the characteristics of alveolar adenoma are not typical on the radiographic images. Therefore, diagnosis of alveolar adenomas is based on the combination of gross structural analysis and immunohistochemistry. The present study described a case of alveolar adenoma in a 47-year-old female patient. A chest X-ray revealed a pulmonary lesion in the right lower lobe and, subsequently, the patient underwent a right lower lobectomy. Pathological examination of the surgically resected tissue confirmed the initial diagnosis of alveolar adenoma. In addition, intracranial vascular malformations were detected on a computed tomography scan, but the patient did not experience any notable symptoms. Considering the benign nature of the malformations, as determined by digital subtraction angiography, the patient selected to undergo follow-up with observation only. The postoperative course was uneventful and no recurrence of pulmonary lesions was noted after >4 years, while the condition of the intracranial lesion was stable. In conclusion, the current study described a unique case of adenoma alveolar coexisting with intracranial vascular malformations. A literature review of previously-reported alveolar adenoma cases was also conducted.

Alveolar adenoma combined with multifocal cysts: case report and literature review.

Alveolar adenoma is an extremely rare and benign pulmonary neoplasm; it is always asymptomatic and is usually detected incidentally on routine chest X-radiography. Typically on imaging examinations, alveolar adenoma exhibits as a peripheral, solitary, cystic nodule in the lung, which may easily imitate other lung lesions, consequently leading to difficulties in the differential diagnosis of this condition. Surgical resection is the primary treatment option. The diagnosis of alveolar adenoma is mainly based on postoperative histopathology, with features of proliferative type 2 alveolar epithelial cells and septal mesenchyme. The present case was a 60-year-old woman with alveolar adenoma, combined with systemic mutifocal cystic lesions. She underwent surgery following the obvious enlargement of this mass and a cystic nodule 7 cm in maximum diameter was resected. Postoperative histopathology confirmed a diagnosis of alveolar adenoma; her prognosis was favourable. In addition to reporting a rare case of alveolar adenoma coexisting with multifocal cysts, the English-language literature was reviewed for similar cases of alveolar adenoma.