Pulmonary sclerosing hemangioma consistently expresses thyroid transcription factor-1 (TTF-1): a new clue to its histogenesis

What's new in benign lung tumours?

While lung cancer is one of the most common malignancies routinely encountered by pathologists, benign pulmonary neoplasms are quite rare. However, it is important for pathologists to be familiar with the typical diagnostic features of benign lung tumors to avoid confusing them with malignant morphological mimics. There have also been intriguing discoveries in the genetics of benign pulmonary neoplasms in the past decade. This review will cover several of the most common benign lung tumors, including the diagnostic categories of pulmonary adenomas, bronchial papillomas, and benign mesenchymal tumors, with discussion of the current classification, differential diagnosis, and current knowledge regarding genetic drivers.

Pulmonary Sclerosing Pneumocytomas Mimicking Lung Cancer

Pulmonary sclerosing pneumocytomas are benign tumors. These tumors are often found incidentally and can be challenging to distinguish from lung malignancies. Here, we describe the case of a 31-year-old woman who presented with an incidental finding of a lung nodule in the lingula. She was asymptomatic and had no history of cancer. Positron emission tomography showed [18F] fluorodeoxyglucose (FDG) uptake in the nodule but no FDG-avid mediastinal lymphadenopathy. In view of these findings, a bronchoscopy was performed, and biopsy samples were taken. The final pathological diagnosis revealed a sclerosing pneumocytoma.

Characteristics of metastatic and non-metastatic pulmonary sclerosing pneumocytomas

To characterize the clinicopathologic features of pulmonary sclerosing pneumocytoma (PSP) and compare these features between the tumors with and without metastasis, 68 cases of PSP (1/68 [1.47%] with metastasis) diagnosed from 2009-2022 in our hospital and 15 previously reported metastasizing cases were studied. There were 54 female patients and 14 male patients, with age ranging from 17 to 72 years and tumor size ranging from 0.1 to 5.5 cm (mean, 1.75 cm). In all, 85.4% of the cases presented with ≥2 patterns, including papillary, sclerotic, solid, and hemorrhagic. Thyroid transcription factor 1, epithelial membrane antigen, CKpan, and CK7 were expressed in surface cells in 100% of the cases and napsin A was expressed in 90% of the cases. Stromal cell expression of these markers occurred in 100%, 93.9%, 13.5%, 13.8%, and 0% of the cases, respectively. Of the 16 PSP cases with metastasis, 8 were female patients and 7 were male patients, with age ranging from 14 to 73 years. The tumor size ranged from 2.5 to 12 cm (mean, 4.85 cm). Forty-five of the cases were negative for BRAF V600E immunostaining and 6 were focally weak positive, in which fluorescent PCR tests showed no detectable mutations. There were significant differences in gender, age, and tumor size between PSP cases with and without metastasis. No BRAF V600E mutation was found in patients with PSP. AKT1 p.E17K mutations were detected in both the primary lung tumor and the lymph node metastatic tumor of our PSP case with lymph node metastasis. In conclusion, PSP is an uncommon pulmonary neoplasm with significant female predilection and has distinct morphologic and immunohistochemical characteristics. The BRAFV600E mutation was not detectable in patients with PSP and thus may not involve in its tumorigenesis. Most PSP tumors are benign, with a minority exhibiting potential for metastasis and malignant behavior.

Sclerosing Pneumocytoma With Pulmonary Sarcoidosis: A Case Report

Pulmonary sclerosing pneumocytoma, formally named pulmonary sclerosing hemangioma, is a rare benign tumor with malignant potential often identified as solid pulmonary nodules. Sarcoidosis is an inflammatory, multisystemic disease of unknown cause with a wide range of clinical manifestations. The disorder is characterized by the formation of noncaseating granulomas in virtually any organ in the body. We present a case of a patient presenting with fever, weight loss, and respiratory symptoms found to have both a sclerosing pneumocytoma and pulmonary sarcoidosis. A diagnosis was made following the lobectomy. The patient was followed for two years with stable lymphadenopathy while remaining asymptomatic.

Sclerosing pneumocytoma with carcinoid tumorlets and neuroendocrine cell hyperplasia

Sclerosing pneumocytoma is an uncommon pulmonary tumor which generally behaves benignly and occurs predominately in women. Rarely, it is associated with neuroendocrine proliferations such as hyperplasia, tumorlets and carcinoid tumors, which may be observed in relation to the tumor or in the distant lung parenchyma; the mechanism underlying this neuroendocrine differentiation is not clear. We present a case of a 33 year-old male with sclerosing pnemocytoma with coexistent neuroendocrine hyperplasia and combined carcinoid tumorlets. Taking into account the pluripotentiality of the round cells present in the sclerosing pneumocytoma, with positive staining for stem cells markers, it is possible that the different components of this neoplasia share a common origin, in accordance with previously reported findings.

Clinical Characteristics of Malignant Pulmonary Sclerosing Pneumocytoma Based on a Study of 46 Cases Worldwide

Objective

To analyze the clinical characteristics of patients with malignant pulmonary sclerosing pneumocytoma (PSP) with metastasis, recurrence, and growth and to improve clinicians’ understanding of PSP in patients with malignant tumor characteristics.

Methods

A total of 46 PSP patients with malignant tumor characteristics were identified in the literature search and compared with 38 patients with benign PSP diagnosed and treated in our hospital in the past 5 years. We explored the pathogenesis, clinical symptoms, diagnostic methods, treatment strategies and prognosis of PSP patients with malignant tumor.

Results

The characteristics of young age (≤41 years old), larger tumor (≥36mm), lymph node metastasis and distribution in East Asians are indicative of PSP with malignant potential. Such patients should undergo segmental resection or lobectomy, combined with necessary lymph node dissection or biopsy. All patients with PSP should have an entire course of follow-up management, because they may have an adverse prognosis such as recurrence, growth, metastasis, and even death.

Conclusion

PSP has the potential for malignancy. Anatomical lobectomy or segmental resection combined with lymph node dissection should be performed in PSP with some specific characteristics. Inappropriate diagnosis and treatment may lead to poor prognosis in PSP patients.

Pulmonary sclerosing pneumocytoma: clinical features and prognosis

BACKGROUND

Pulmonary sclerosing pneumocytoma is a kind of rare benign pulmonary tumor with potential malignancy. The clinical features, risk factors for prognosis, and optimal treatment have not been identified yet. This study aimed to investigate the clinical features and prognosis of pulmonary sclerosing pneumocytoma.

METHODS

We retrospectively performed a review of pulmonary sclerosing pneumocytoma patients in West China Hospital from 2009 to 2019. The basic characteristics, treatment regimens, operation detail, postoperative variables, and follow-up time were recorded for each case. Differences in features between patients undergoing lobectomy and segmentectomy were compared. We also performed a case review and summarized reported clinical features in former studies.

RESULTS

Altogether 61 pulmonary sclerosing pneumocytoma patients were retrospectively reviewed. Fifty-six patients were female and 5 were male. The patients' median age was 51 (23-73). Seven (11.48%) patients had smoking history. Twenty tumors were located in the right lung [upper lobe (n = 7), middle (n = 2), and lower (n = 11)] and 41 in the left [upper (n = 12) and lower (n = 29)]. The median tumor size was 2 (0.9-7) cm. Thirty-six (59.02%) patients underwent sublobectomy (segmentectomy or wedge resection) whereas 25 (40.98%) underwent lobectomy. All patients recovered uneventfully, and no perioperative mortality was identified. Sublobectomy showed a trend towards reduced chest tube duration and shorter postoperative hospital stays compared with lobectomy.

CONCLUSIONS

The findings showed good prognosis of pulmonary sclerosing pneumocytoma and proved its benign characteristics. Sublobectomy showed advanced efficacy regarding chest tube duration and postoperative hospital stay compared with lobectomy.

Pulmonary sclerosing pneumocytoma-a case series

Pulmonary sclerosing pneumocytoma (PSP) is a rare and interesting pulmonary tumour that presents a diagnostic challenge to the surgeon due to its bland symptomatology, indolent course, non-specific radiological features and ambiguous histopathological findings, which could lead to errors in management and prognostication. Herein, we present a series of 4 patients with PSP who were managed in our institution over a period of 8 years and briefly discuss relevant literature.

Analysis of the F-18 FDG PET/CT features of pulmonary sclerosing pneumocytoma

PURPOSE

This retrospective study aimed to analyzed the F-18 fluorodeoxyglucose PET/computed tomography (F-18 FDG PET/CT) features of pulmonary sclerosing pneumocytoma (PSP) to improve the understanding and preoperative diagnostic efficacy of this rare disorder.

METHODS

FDG PET/CT images from 11 patients with 22 lesions (including one patient with 12 lesions) proven PSP in our hospital were reviewed. We summarized the PET/CT features of PSP and analyzed the correlation between FDG uptake and tumor size.

RESULTS

PET/CT imaging revealed all tumors located in each lobe of the two lungs randomly. All 22 tumors were round or oval nodules; 15 had smooth margins, six were lobulated, six were calcified, and one had a ground-glass halo sign. The mean diameter of these tumors was 19.2 ± 7.8 mm (range: 8-34 mm); the mean maximum standardized uptake value (SUVmax) was 2.8 ± 1.3 (range: 1.1-7.4). Sixteen of the lesions exhibited mild to moderate FDG uptake (mean SUVmax 2.3 ± 0.6), and six of the lesions exhibited intense FDG uptake (mean SUVmax 4.3 ± 1.6). A positive correlation was observed between FDG uptake and tumor size (P <0.05).

CONCLUSION

Single round or ovoid soft-tissue lesions with smooth margins, and mild to moderate FDG uptake on PET/CT images in middle-aged females, suggest a possible diagnosis of PSP. For some atypical cases with intense FDG uptake, a diagnosis of PSP also can be considered. A statistically significant positive correlation was found between SUVmax and PSP lesion size in our study.

Huge Pulmonary Sclerosing Pneumocytoma with Endobronchial Invasion: A Case Report with a Literature Review

Pulmonary sclerosing pneumocytoma (PSP) is a tumor of pneumocytic origin that is classified as a benign neoplasm. To date, aggressive behavior of this tumor has rarely been reported. Here, we describe a case of a 56-year-old woman with a huge, 19-cm PSP that resulted in mediastinal shift and showed microscopic endobronchial invasion and necrosis. The differential diagnosis included malignant mesenchymal tumors, such as solitary fibrous tumor; however, PSP was confirmed based on the characteristic thyroid transcription factor 1 positivity and membranous expression of Ki-67 on immunohistochemical staining of tumor cells.

Benign tumours of the bronchopulmonary system

The vast majority of tumours arising in the bronchopulmonary system are malignant in nature. Benign tumours of the lung are relatively rare and are often incidental findings during clinical investigations for unrelated conditions. These lesions can arise in the bronchial tree or the pulmonary parenchyma and may be of epithelial, mesenchymal, salivary gland-type or unknown differentiation. Although the spectrum of these lesions is wide, the clinical, pathological and immunohistochemical characteristics of the most relevant will be the subject of this review. In addition, the most important features allowing differentiation from malignant pulmonary neoplasms will be discussed.

Molecular Genetic Landscape of Sclerosing Pneumocytomas

OBJECTIVES

Sclerosing pneumocytomas are rare pulmonary neoplasms that are typically benign. However, rare patients experience progressive disease, and therapy targeting specific genetic underpinnings could be an attractive therapeutic option. Recent studies have found recurrent AKT 1 mutations in sclerosing pneumocytoma, but little is known about whether oncogenic fusion genes may also be present.

METHODS

To better understand the genetic background, 10 sclerosing pneumocytomas were subjected to next-generation sequencing cancer mutation panel testing (n = 9) and/or RNA sequencing (n = 3). The patients were all women (average age, 47 years; range, 17-74 years).

RESULTS

Eight patients had solitary sclerosing pneumocytomas, while one had two tumors, and one had many bilateral tumors. Recurrent mutations were noted in genes involved in the mTOR pathway, including AKT1, PIK3R1, and PTEN. AKT1 alterations were particularly common, present in 78%. No recurrent genetic fusions were identified. The patient in our study with multiple bilateral lesions was treated with the mammalian target of rapamycin (mTOR) inhibitor everolimus, with no objective radiographic evidence of treatment response after 4 months.

CONCLUSIONS

Our data further support that abnormal activation of the mTOR pathway is a consistent genetic event in sclerosing pneumocytoma. This warrants further exploration to determine if mTOR pathway inhibitors may be effective in patients with metastatic or recurrent disease.

Clinical and histopathological features of pulmonary sclerosing pneumocytoma with dense spindle stromal cells and lymph node metastasis

AIMS

To determine the clinicopathological features of pulmonary sclerosing pneumocytoma (PSP) with spindle cells and in cases with positive detection of PSP cells in the lymph nodes.

METHODS AND RESULTS

This article report the clinical, histological and immunohistochemical features of PSP with dense spindle stromal cells in five patients (including one case with lymph node metastasis) and PSP accompanied by positive nodes in two patients out of 239 cases diagnosed at our institution between 2007 and 2019. The literature on PSP was also reviewed in detail. Six patients were female, and one (with a positive node) was male; their average age was 53 years. Thoracic imaging revealed solid tumours with clear borders and a uniform texture in six patients, but one patient had a lobulated tumour with uneven densities. All tumours were unifocal, and they had an average size of 31 mm. Tumours from five cases were mainly composed of solid regions of diffuse spindle cells rather than polygonal cells. Immunohistochemical staining demonstrated that thyroid transcription factor-1, vimentin, epithelial membrane antigen (weak) and oestrogen receptor (partial) were expressed in spindle cells. The average follow-up time was 31 months. Two of the 234 PSP cases for which adequate data were available had positive nodes (metastasis rate: 0.8%), and one of the five patients with PSP with spindle cells showed lymph node metastasis (metastasis rate: 20%). In addition, stromal cells were found to be predominant at metastatic sites.

CONCLUSIONS

Spindle cells are present among the stromal cells of PSP, and not all of them are round cells. PSP patients with spindle cells or male patients may be more prone to metastasis than others.

Pulmonary sclerosing pneumocytoma in an 18-year-old male patient: A case report and literature review

RATIONALE

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign tumor of the lung, mostly presented in Asian middle-aged women. Initially, it was considered as a vascular origin tumor, but then research evidence showed that it was derived from natural epithelial tissue. On imaging, this tumor may be found as a solitary well-circumscribed lung parenchymal lesion, and is often located in juxtapleural or juxtafissural positions. On histopathology, it consists of cuboidal surface cells and stromal round cells, both of which are positive for thyroid transcription factor-1. Here we report a case of a young PSP male patient and review the relevant literature in order to improve our understanding of this disease.

PATIENT CONCERNS

An 18-year-old man was referred to our hospital after accidentally finding a lesion on chest X-ray. Contrast-enhanced computed tomography showed a soft tissue mass with homogeneous enhancement in the left lower lobe posterior segment.

DIAGNOSES

The diagnosis of PSPs was confirmed by histopathological examination.

INTERVENTIONS AND OUTCOMES

The patient underwent a thoracoscopic wedge resection and was followed-up after that. One month later, he had good performance status with no recurrent tumors.

LESSONS

PSP in a young man is really uncommon, and is confused with malignant tumors. A histopathological examination is considered as the diagnostic gold standard for this uncommon tumor. Surgery is the main treatment.

First report of pulmonary sclerosing pneomucytoma with malignant transformation in both cuboidal surface cells and stromal round cells: a case report

BACKGROUND

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign tumor. Although lymph node metastasis has been reported, it is still considered benign. No malignant transformation has been reported. This is the first case of malignant transformation of both cuboidal surface cells and stromal round cells.

CASE PRESENTATION

A 64-year-old male had been complaining of intermittent hemoptysis several times per day for eight months. Chest computed tomography scan showed parenchymal infiltration with cystic lesion in the right lower lobe accompanied by enlarged right hilar lymph nodes. Lobectomy and systemic lymph node dissection was performed. On grossly pathological examination, the lesion was 50 mm from the bronchial stump. It was a mixture of both cystic and solid components and 30 mm * 20 mm in size with unclear border. Microscopically, the cuboidal surface cells transformed to adenocarcinoma. The stromal round cells also had a malignant transformation. The Ki-67 proliferation index in malignant cuboidal surface cells and stromal round cells were 70 and 55%, respectively. Furthermore, E-cadherin was negative in primary tumor but positive in metastatic lymph node, which suggested that the mesenchymal to epithelial transition may play an important role in lymph node metastasis.

CONCLUSIONS

To our knowledge, we present the first case of malignant transformation of both cuboidal surface cells and stromal round cells in PSP. The process of mesenchymal to epithelial transition may play an important role in lymph node metastasis.

Sclerosing pneumocytoma: Case report of a rare endobronchial presentation

RATIONALE

Sclerosing pneumocytoma is a rare benign lung neoplasm seen in middle aged adults with a female predominance. Originally thought to be vascular in origin, this rare entity is now understood to be epithelial in nature. On imaging, sclerosing pneumocytoma manifests as a well circumscribed nodule or mass, often juxtapleural in location. On histopathology, sclerosing pneumocytoma is composed of cuboidal "surface cells" and round "stromal cells," both of which show nuclear staining for thyroid transcription factor-1 (TTF-1). Here we review the existing literature on sclerosing pneumocytoma and present a case of sclerosing pneumocytoma in a highly unusual endobronchial location.

PATIENT CONCERNS

This case is a 43 year old woman who presented with chronic cough.

DIAGNOSIS

Imaging revealed a right upper lobe nodule with an endobronchial component.

INTERVENTIONS AND OUTCOMES

Endoscopic biopsy was performed, and pathologic diagnosis was confirmed.

LESSONS

Although extremely rare, endobronchial presentation of sclerosing pneumocytoma is possible, and should remain on the differential for patients with endobronchial pulmonary lesions. Pathologic tissue analysis is necessary to confirm this uncommon diagnosis.

Ectopic ACTH Syndrome With Association of Multiple Pulmonary Sclerosing Pneumocytomas and Multiple Carcinoid Tumorlets

We present the case of multiple sclerosing pneumocytomas (SPs) associated with ACTH-secreting carcinoid tumorlets responsible for an ectopic Cushing syndrome (ECS). SP is a rare benign tumor originating from pulmonary epithelial cells. An 18-year-old male presented with shortness of breath and right-sided chest pain after exercise. Chest radiograph indicated right pneumothorax and bilateral lung nodules. CT imaging showed innumerable bilateral hypodense pulmonary nodules and a wedge resection gave the definitive diagnosis of SP with associated carcinoid tumorlets. Two years later, he presented with severe back pain in context of thoracic vertebral compression fracture. He had central fat accumulation, violaceous striae, proximal muscle weakness, hypertension, and diabetes. MRI of the pituitary gland showed a 7-mm adenoma. Inferior petrosal sinus sampling with no central-to-periphery gradient suggested an ectopic origin of ACTH, which was confirmed by ACTH expression in a subset of tumorlet cells in the lung lesions. The patient was started on ketoconazole and subsequently underwent a bilateral adrenalectomy. During follow-up, CT scans showed no growth of the lesions, except for the most recent CT scan, in which an increase in the size of the largest nodule was described. Ten years after the diagnosis, the patient remains asymptomatic of his pulmonary lesions. This article provides a case of ECS in the setting of multiple SP with associated carcinoid tumorlets.

Pulmonary sclerosing pneumocytoma presenting as slow-growing multiple nodules over a long period

Pulmonary sclerosing pneumocytoma is an uncommon slow-growing benign tumor that usually occurs in middle-aged women and generally presents as a solitary well-defined nodule. An 18-year-old woman was incidentally detected to have multiple lung nodules on chest radiography that slowly increased in size over a period of 7 years. Computed tomography images showed multiple well-defined nodules surrounded by numerous smaller nodules with a maximum diameter of 3 cm in the left lung. A percutaneous core needle biopsy was performed, but malignancy could not be excluded because of the high proportion of papillary structures. A video-assisted partial wedge resection was performed and the pathologic diagnosis was pulmonary sclerosing pneumocytoma. Pulmonary sclerosing pneumocytoma presenting as multiple lung nodules is a rare but very important condition to include in the differential diagnosis of multiple lung nodules. There is a possibility of misdiagnosis of another type of tumor or malignancy on preoperative biopsy. We should be aware not only of the clinical, radiologic, and pathologic features of pulmonary sclerosing pneumocytoma but also of the potential pitfalls in its diagnosis and management.

Pulmonary sclerosing pneumocytoma, a rare tumor of the lung

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign pulmonary tumor. Usually diagnosed incidentally by chest X-ray or chest CT scan. We presented a case of PSP in a 50-year-old woman who was diagnosed with a nodular lesion in the right lung. Thoracotomy was used for the excision of the mass. Pathologic examination revealed no malignant cells. Immunohistochemical studies were performed. TTF-1 was (+), Napsin-A was found to be weakly (+). After surgical resection, the patient was followed up.

Pulmonary sclerosing pneumocytoma remains a diagnostic challenge using frozen sections: a clinicopathological analysis of 59 cases

AIMS

Using intraoperative frozen sections to diagnose pulmonary sclerosing pneumocytoma is always challenging. However, an accurate diagnosis is needed to guide surgical management and prevent unnecessary treatment. The aim of this study was to investigate the most frequently misdiagnosed histological patterns and evaluate the potential diagnostic pitfalls of using frozen sections.

METHODS AND RESULTS

We reviewed retrospectively 59 cases of sclerosing pneumocytoma that underwent an intraoperative frozen section examination. All original frozen section slides and permanent section slides were reviewed. The rate of accurate diagnosis using frozen sections was 44.1%, the deferral rate was 15.3% and 10 cases (16.9%) were misdiagnosed as malignancy. A solid-predominant pattern is misdiagnosed more frequently than other growth patterns. We also summarised the five major diagnostic pitfalls, including hypercellularity, glandular spaces, desmoplasia-like sclerosis, cellular atypia and coagulative necrosis.

CONCLUSIONS

In addition to evaluating the tumour circumscription and identifying the various growth patterns, we propose that the key to avoiding a misdiagnosis is to recognise the dual-cell populations in a tumour, i.e. cuboidal surface cells and stromal round cells.

Imprint cytologic and immunocytochemical findings of sclerosing pneumocytoma

To the best of our knowledge, there is no description on immunocytochemical study of sclerosing pneumocytoma (SP) using a cell transfer method. In this article, we report imprint cytological and immunocytochemical findings of SP. Three cases of SP possessing both imprint cytological and histological materials were examined. All tumors showed well-defined margin grossly. On microscopic examination, the tumor consisted of surface and stromal round cells. Cytologically, surface and stromal round cells showed fragments or clusters of papillary configuration with low N/C ratio and cell clusters of small to medium-sized cells with high N/C ration. Immunocytochemically, surface cells showed the positive reaction for surfactant apoprotein A (SPA), but stromal round cell exhibited the negative reaction for SPA. Cytologists and pathologists should steadily recognize cytological findings of surface and stromal round cells of SP. Immunocytochemistry of SPA may be useful in the discrimination of both cells. Diagn. Cytopathol. 2017;45:274-278. © 2016 Wiley Periodicals, Inc.

The 2015 World Health Organization Classification of Lung Tumors: Impact of Genetic, Clinical and Radiologic Advances Since the 2004 Classification

The 2015 World Health Organization (WHO) Classification of Tumors of the Lung, Pleura, Thymus and Heart has just been published with numerous important changes from the 2004 WHO classification. The most significant changes in this edition involve (1) use of immunohistochemistry throughout the classification, (2) a new emphasis on genetic studies, in particular, integration of molecular testing to help personalize treatment strategies for advanced lung cancer patients, (3) a new classification for small biopsies and cytology similar to that proposed in the 2011 Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification, (4) a completely different approach to lung adenocarcinoma as proposed by the 2011 Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification, (5) restricting the diagnosis of large cell carcinoma only to resected tumors that lack any clear morphologic or immunohistochemical differentiation with reclassification of the remaining former large cell carcinoma subtypes into different categories, (6) reclassifying squamous cell carcinomas into keratinizing, nonkeratinizing, and basaloid subtypes with the nonkeratinizing tumors requiring immunohistochemistry proof of squamous differentiation, (7) grouping of neuroendocrine tumors together in one category, (8) adding NUT carcinoma, (9) changing the term sclerosing hemangioma to sclerosing pneumocytoma, (10) changing the name hamartoma to "pulmonary hamartoma," (11) creating a group of PEComatous tumors that include (a) lymphangioleiomyomatosis, (b) PEComa, benign (with clear cell tumor as a variant) and

The significance of p40 expression in sclerosing hemangioma of lung

To explore the histogenesis of cuboidal and polygonal tumor cells in the sclerosing hemangioma of lung (SHL), eighteen cases of SHL were retrospectively studied. SPB, p40, TTF-1,EMA,CKpan, vimentin,SMA, CgA,Syn and CD34 were immunohistochemically labeled by the EnVisionmethod. It was found that the four main types of structure in SHL were solid,papillary, hemorrhagic and sclerotic patterns. The tumor cells were composed mainly of two types of cells: cuboidal tumor cells and polygonal tumor cells. The immunohistochemistry showed that p40 was expressed only in cuboidal tumor cells. TTF-1 and EMA were expressed in both polygonal cells and cuboidal cells. SPB was also expressed in cuboidal tumor cells; vimentin was expressed in all polygonal tumor cells and some cuboidal cells. The findings suggest that the p40-positive cuboidal tumor cells may be pluripotent original respiratory epithelial cells, with multi-directional differentiation capacity.

Pulmonary sclerosing hemangioma with lymph node metastasis: A case report and literature review

Pulmonary sclerosing hemangioma (SH) is an uncommon benign or low-grade malignant tumor. Multicentric SH and SH with lymph node metastasis have rarely been reported. The present report describes a case of pulmonary SH with lymph node metastasis in a middle-aged female. A nodule was found incidentally in the lower left lung. The patient underwent left lower pulmonary lobectomy and lymph node dissection. Histologically, the nodule demonstrated the characteristic features of SH and one of the resected lymph nodes contained a metastasis of this tumor. Thus, pulmonary SH has the potential to metastasize, a potential not suggested by histological features.

Multiple peripheral typical carcinoid tumors of the lung: associated with sclerosing hemangiomas

Abstract

This study presents a first case of multiple peripheral typical carcinoid tumors associated with sclerosing hemangiomas in the lung. A 52-year-old male presented with incidentally detected multiple pulmonary nodules on a simple chest X-ray during routine health check-up. A computed tomography (CT) scan of the chest showed multiple nodular lesions in the middle and lower lobes of the right lung. These were initially suspected as inflammatory lesions due to miliary tuberculosis. However, possibility of malignancy could not be excluded and right lower lobe lobectomy was performed. Histopathologically, some nodules including two largest nodules were composed of small round to spindle shaped cells with fine chromatin pattern, whereas the rest of the sclerotic nodules were composed of two epithelial cell types- surface cells and round cells. The final diagnosis of this case was multiple peripheral typical carcinoid tumors associated with sclerosing hemangiomas of the lung. For past three years of post-surgery follow up period, no new lesions or changes in the right middle lobe have been identified.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1511610609725790.

Pulmonary sclerosing hemangioma: a unique epithelial neoplasm of the lung (report of 26 cases)

BACKGROUND

Pulmonary sclerosing hemangioma (SH) is an uncommon tumor. The aim of this study was to identify the origin of pulmonary SH and summarize its clinicopathologic features.

METHODS

Data of 26 cases of pulmonary SH were collected and reviewed, including their clinical symptoms, chest radiological examinations, treatments, and pathological findings.

RESULTS

Female patients of pulmonary SH were markedly frequent (n=23, 88.46%). Solitary mass or nodule in the lung fields was the most common manifestation (n=24, 92.31%), especially in the right middle lobe (n=9, 34.62%). There were two kinds of tumor cells: lining cells and round cells. All tumors contained a mixture of papillary, solid, sclerotic, and hemorrhagic patterns. Immunohistochemistry with a variable number of antibodies was performed for some cases. All of the detected specimens revealed strong reaction of lining cells with epithelial markers, such as thyroid transcription factor-1 (TTF-1), epithelial membrane antigen (EMA), cytokeratin (CK), pancytokeratin (PCK), and cytokeratin 7 (CK-7), while round cells were positive with TTF-1 and EMA. Until the end of last contact, none of the patients died or suffered from the recurrence of the disease after surgical treatment.

CONCLUSIONS

Pulmonary SH is a unique neoplasm of the lung with a characteristic solitary mass or nodule. Pulmonary epithelium might be the primary origin of the tumor cells.

Value of thyroid transcription factor-1 immunostaining in tumor diagnosis: a review and update

Thyroid transcription factor-1 (TTF-1) is a tissue-specific transcription factor that plays a critical role in the normal development of embryonic epithelial cells of the thyroid and lung. Because TTF-1 expression is highly restricted to epithelial tumors arising in these organs, it is, at present, one of the immunohistochemical markers most commonly used to assist in the differential diagnosis of carcinomas of the lung and thyroid. Recent studies, however, have reported that TTF-1 is not as specific for lung and thyroid carcinomas as was previously thought as it can be found to be expressed, although much less frequently, in some carcinomas arising in other organs, such as the ovaries, endometrium, colon, and breast, as well as in some tumors of the central nervous system. Even though this unexpected TTF-1 positivity has been reported more frequently with the recently available SPT24 anti-TTF-1 monoclonal antibody, it has also been shown to occur with the commonly used 8G7G3/1 clone, albeit in a lower percentage of cases. Despite these findings, TTF-1 remains a very useful immunohistochemical marker in diagnostic pathology.

Symptomatic sclerosing haemangioma: a rare case of solitary pulmonary nodule in a young girl

Sclerosing haemangioma (SH) is a rare benign lung tumour with distinctive variety of histological patterns. SH typically presents as asymptomatic peripheral, solitary well-circumscribed lesion in women with median age at diagnosis in the fifth decade. Preoperative diagnosis of this tumour is difficult, and sometimes even intraoperative frozen sections cannot differentiate it from malignant tumours. Here, we present our experiences in investigating its characteristics. We report a case of a 19-year-old girl who presented with chest pain, cough and sputum and off and on haemoptysis for 6 months. Anti-tubercular treatment was given but provided no relief. CT chest showed a well-defined hypodense solid mass lesion with a soft tissue alternation. Lobectomy was performed. Microscopy revealed a tumour comprising of two distinct populations of cells surface and stromal cells which disposed in papillary, solid, sclerotic and haemorrhagic growth patterns. Histology and immunohistochemistry confirmed the diagnosis of SH of the lung.

Napsin A Is Differentially Expressed in Sclerosing Hemangiomas of the Lung

Context.—Sclerosing hemangiomas (SH) are lung tumors characterized by surface cuboidal cells and round stromal cells. The cell of origin remains controversial, though immunohistochemical and ultrastructural studies suggest primitive respiratory epithelium. Napsin A, a human aspartic proteinase found primarily in type II pneumocytes and alveolar macrophages, is emerging as a helpful immunohistochemical marker in characterizing the origin of lung neoplasms, and may be of use in evaluating SH.

Objective.—To evaluate napsin A immunohistochemical staining in SH to further characterize the cell of origin.

Design.—Six cases of SH were stained for napsin A, as well as thyroid transcription factor 1 and cytokeratin in selected cases.

Results.—Surface and round cells were positive for thyroid transcription factor 1 in all cases stained with this marker. Cytokeratins were positive in surface cells in all cases stained with this marker; 2 cases had focal cytokeratin staining in round cells. Round cells had focal napsin A staining in 1 case (17%); surface cells were napsin positive in all cases.

Conclusions.—The observation of thyroid transcription factor 1 positivity in both surface and round cells in all SH suggests primitive respiratory epithelium as the cell of origin of SH. Our napsin A findings support this, with positivity in surface cells of all tumors (100%), and focal round cell staining in only 1 (17%). In fact, surface cells may represent entrapped type II pneumocytes, which normally express napsin A in a granular cytoplasmic pattern, similar to surface cells. The coexpression of thyroid transcription factor 1 and napsin A also introduces a caveat in differentiating primary pulmonary adenocarcinomas from SH in small biopsy specimens.

Neoplastic and nonneoplastic benign mass lesions of the lung

While most lung neoplasms are malignant, a subset of true neoplasms are benign, the most common of which are pulmonary hamartomas. In addition, a substantial proportion of lung mass lesions are nonneoplastic; granulomas are among the commonly encountered nonneoplastic masses. There is also a group of relatively rare, mainly inflammatory and fibrous tumor-like lesions that are encountered on core biopsy and excisions of lung tissue.

Treatment of 28 patients with sclerosing hemangioma (SH) of the lung

Background

Sclerosing hemangioma (SH) of the lung is a kind of rare pulmonary tumor. Preoperative diagnosis of this tumor is difficult and it is now generally accepted that SH of the lung is benign lesions and surgical excision alone is curative. Herein, we present our experiences of treating 28 patients with SH.

Methods

The medical records of 28 patients with SH from 1994 to 2010 at the Department of Thoracic Surgery in Beijing Chest Hospital were retrospectively reviewed.

Results

There were 3 male and 25 female patients with sclerosing hemangioma and 50% of the patients were asymptomatic. Preoperatively, all the patients had undergone CT of chest and 5 patients had undergone PET scan but 4 patients were misdiagnosed as malignancy. There was no operative mortality or tumor recurrence despite that three different operative methods were undertaken.

Conclusions

SH has a high incidence in middle-aged women. Most of SH is asymptomatic and the symptoms of SH are not related to the tumor size and distribution. The features of chest CT and PET are not specific. Bilateral or multiple lesions should not exclude the possibility of SH. Complete excision of lesion is a curable treatment method and there is no evidence to verify the need of adjuvant therapy.

A case of sclerosing hemangioma forming a pedunculated mass

We report our experience with an unusual case of sclerosing hemangioma (SH) that formed a pedunculated mass protruding into the thoracic cavity. A pulmonary tumor was found in a 60-year-old female during the medical examination. Computed tomography showed a 19 × 17-mm nodule with a clear border and smooth margin contiguous with the diaphragm in the right S8 segment. Uneven enhancement following contrast medium administration was observed. We performed a 3-port thoracoscopic wedge resection of the right lower lobe. We observed a yellow pedunculated tumor protruding from the diaphragmatic surface of the right lower lobe. The surface of the tumor was smooth and encapsulated. Microscopically, we diagnosed it as a SH. SHs usually exist adjacent to the visceral pleura, but rarely form pedunculated tumors protruding into the cavity as seen in this case. By thoracoscopic surgery, we successfully diagnosed and treated the patient in a minimally invasive manner. Since there have been reported cases of recurrence, we anticipate that periodic follow-up observations will be required.

Microscopic sclerosing hemangioma diagnosed by histopathological examination after lung cancer surgery

A 44-year-old woman underwent surgery for lung cancer. Although preoperative computed tomography did not reveal a tiny nodule, pathological examination of the background lung showed that type II pneumocyte-like tumor cells grew papillary in an area of approximately 2.3 × 1.2 mm. This lesion exhibited hemorrhage, hemosiderosis, calcification, and varying degrees of fibrosis, leading to the diagnosis of sclerosing hemangioma. This is the first reported case of microscopic sclerosing hemangioma undetectable by chest computed tomography.

Cytologic features of sclerosing hemangioma of the lung on crush preparations

Sclerosing hemangioma of the lung is a rare benign neoplasm. The majority of the literature published on sclerosing hemangioma has focused on the histologic features, while only a few case reports have described the cytologic features. We report two additional cases of sclerosing hemangioma of the lung in which the cytologic material was prepared at the time of frozen section. Because of the rarity of this lesion and the overlapping cytologic features with other primary malignant lung tumors, awareness of the cytologic features of sclerosing hemangioma may help to avoid a diagnosis of malignancy. This is especially true pre- and intraoperatively because a limited resection may suffice if a diagnosis of sclerosing hemangioma can be established.

Pulmonary sclerosing hemangioma in a 21-year-old male with metastatic hereditary non-polyposis colorectal cancer: report of a case

Background

Pulmonary sclerosing hemangioma (SH) is a rare tumor of the lung predominantly affecting Asian women in their fifth decade of life. SH is thought to evolve from primitive respiratory epithelium and mostly shows benign biological behavior; however, cases of lymph node metastases, local recurrence and multiple lesions have been described.

Case Presentation

We report the case of a 21-year-old Caucasian male with a history of locally advanced and metastatic rectal carcinoma (UICC IV; pT4, pN1, M1(hep)) that was eventually identified as having hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome). After neoadjuvant chemotherapy followed by low anterior resection, adjuvant chemotherapy and metachronous partial hepatectomy, he was admitted for treatment of newly diagnosed bilateral pulmonary metastases. Thoracic computed tomography showed a homogenous, sharply marked nodule in the left lower lobe. We decided in favor of atypical resection followed by systematic lymphadenectomy. Histopathological analysis revealed the diagnosis of SH.

Conclusions

Cases have been published with familial adenomatous polyposis (FAP) and simultaneous SH. FAP, Gardner syndrome and Li-Fraumeni syndrome, however, had been ruled out in the present case. To the best of our knowledge, this is the first report describing SH associated with Lynch syndrome.

Coexistence of pulmonary sclerosing hemangioma and primary adenocarcinoma in the same nodule of lung

Pulmonary sclerosing hemangiomas (PSH) of the lung are uncommon tumors and may present cytological atypia with unusual manifestations. The development of PSH combined with other different tumors in lung is extremely rare. We report a case of coexistence of PSH and primary adenocarcinoma in a young female occurring in the same pulmonary nodular mass of right lower lobe. The solitary mass of lung was well-circumscribed on chest computed tomography (CT) and gross examination. Histologically, the mass contained two separated portions and displayed typically histological features of PSH and acinar adenocarcinoma, respectively. In PSH portion, the tumor was composed of sheets of round cells with scattered surface cuboidal cells forming small tubules. Both round and surface cells were diffusely positive for epithelial membrane antigen (EMA) and thyroid transcription factor-1 (TTF-1), but lack immunoreactivity for pancytokeratin in round cells. In adenocarcinoma portion, the tumor cells formed irregular-shaped glands with cytologically malignant cells infiltrating in fibroblastic stroma, and no TTF-1-positive round cells could be observed in this portion. Under the microscopy, there was no gradual transition of these two portions observed in mass. A diagnosis of PSH combined with primary adenocarcinoma of lung was made. There was no evidence of tumor recurrence during the period of postoperative 6-month follow-up. To our knowledge, this is the first case of coexistence of PSH and adenocarcinoma in the same nodule of lung. In addition, the biological behavior and histological differential diagnosis of this tumor were also discussed.

So-called sclerosing hemangioma of lung: current concept

Sclerosing hemangioma of the lung is a rare neoplasm with polymorphic histologic features. Despite various patterns, there are 2 unifying cellular components: "surface cells" and "round cells." Although histogenesis has been debated for decades, most ultrastructural, immunocytochemical, and molecular studies strongly indicate a neoplastic epithelial derivation for both cellular components. Herein, we present a review of sclerosing hemangioma and summarize the essential data regarding histologic, cytologic, and ancillary findings of this distinctive pulmonary neoplasm.

Sclerosing hemangioma of the lung

We present a brief review of sclerosing hemangioma, an uncommon but histologically distinctive neoplasm of the lung. Based on immunohistochemical and molecular findings, sclerosing hemangioma is thought to be derived from incompletely differentiated respiratory epithelium. Sclerosing hemangiomas typically present as asymptomatic, peripheral, solitary, well-circumscribed lesions in women with a mean age at diagnosis in the fifth decade. Rare cases are reported to have regional lymph node metastases; however, metastases do not appear to affect long-term survival. Histologically, sclerosing hemangioma is characterized by a distinct constellation of findings including 2 epithelial cell types, surface cells and round cells, which form 4 architectural patterns, papillary, sclerotic, solid, and hemorrhagic. Sclerosing hemangioma of the lung is generally considered to be a benign lesion, and surgical excision is curative without the need for additional treatment.

[A rare case of multiple sclerosing hemangiomas of the lung]

Sclerosing hemangioma of the lung is an uncommon benign tumour which usually presents as an asymptomatic solitary nodule. Multiplicity is very rare. The authors describe a case of a 50 year-old asymptomatic woman with multiple nodular lesions involving all the lobes of both lungs, which underwent diagnostic thoracotomy after thorough investigation to exclude extra-pulmonary neoplasia. The biopsies obtained led to the diagnosis of pulmonary sclerosing hemangiomas. This is one of the few cases described with this presentation.

Benign Tumors and Tumorlike Conditions of the Lung

Context.—Benign tumors and tumorlike conditions of the lung are encountered in the pathologic evaluation of asymptomatic and symptomatic lung nodules. Since many of these lesions are uncommon, they can be diagnostically challenging.

Objective.—To review the current classification of benign lung tumors, with emphasis on histopathology and useful ancillary studies.

Data Sources.—The current World Health Organization classification system for lung neoplasms and review of relevant publications.

Conclusions.—Despite improved imaging techniques, benign lung nodules are encountered in wedge biopsy and resection specimens. Histopathology, immunohistochemistry, and molecular techniques ensure accurate pathologic diagnosis and have shed light on the histogenesis of these unusual lesions.

Microsatellite and EGFR, HER2 and K-RAS analyses in sclerosing hemangioma of the lung

Sclerosing hemangioma (SH) is an uncommon pulmonary tumor thought to derive from primitive respiratory epithelium consisting of 2 cell populations (cuboidal surface and polygonal stromal cells) and sharing some clinical characteristics (frequent occurrence in nonsmoking women of Asian ethnicity) with bronchioloalveolar carcinoma with which it has been suggested a possible common origin. We investigated 11 cases of SH by immunohistochemistry, fluorescence in situ hybridization, and polymerase chain reaction-based microsatellite and mutational analyses with particular emphasis on possible alterations of microsatellite loci located at tumor suppressor genes (FHIT, p16, Rb, and p53) involved in lung adenocarcinoma genesis and EGFR, HER2, and K-RAS genes. Although EGFR expression was observed in all tested cases, none showed HER2 immunostaining. Fluorescence in situ hybridization and mutational analysis of EGFR and HER2 and also K-RAS sequencing did not reveal molecular alterations, whereas allelic losses at p16 and Rb loci (4 and 2 out of 9 tested cases, respectively) with an identical microsatellite allelic loss pattern in both cuboidal and polygonal cells were observed. The finding of microsatellite alterations in chromosomal regions related to genes deeply involved in early stage lung adenocarcinoma could suggest a possible link between SH and bronchioloalveolar carcinoma, but tumor pathway promoted by EGFR, HER2, and K-RAS does not represent a common molecular mechanism of tumorigenesis. Microsatellite alterations identified in cuboidal and polygonal cells further confirm the clonal and neoplastic nature of both components of SH.

Gene expression and clonality analysis of the androgen receptor and phosphoglycerate kinase genes in polygonal cells and cuboidal cells in so-called pulmonary sclerosing hemangioma

The histogenesis of polygonal cells and cuboidal cells in so-called pulmonary sclerosing hemangioma remains unclear. To understand their histogenesis, polygonal and cuboidal cells were obtained from pulmonary sclerosing hemangioma tissue using a laser capture microdissection technique. Genomic DNA and total RNA were extracted and mRNA levels of cytokeratin, epithelial membrane antigen, vimentin, surfactant protein B, thyroid transcription factor-1, synaptophysin, and chromogranin-A were analyzed by RT-PCR. DNA was digested with the methylation-sensitive enzymes HhaI or HpaII, followed by nested PCR of the androgen receptor and phosphoglycerate kinase genes. Samples with polymorphisms were identified and a clonality analysis was performed. The cytokeratin, epithelial membrane antigen, and surfactant protein B genes were clearly expressed in cuboidal cells, while the vimentin and synaptophysin genes were clearly expressed and the epithelial membrane antigen gene was weakly expressed in polygonal cells. Thyroid transcription factor-1 was expressed in both cell types, while neither cell type expressed chromogranin-A. Clonality analysis showed the same loss of allele in both cell types (clonality ratio=0) or an unbalanced methylation pattern (clonality ratio<0.25). Polygonal and cuboidal cells in pulmonary sclerosing hemangioma exhibited a uniform pattern of monoclonality, indicating that both cell types are highly likely to originate from a common precursor. The differences in their morphological phenotype might result from their different mature status.

Expression of E-cadherin, β-catenin and p120ctn in the pulmonary sclerosing hemangioma

BACKGROUND

The major two types of cells in pulmonary sclerosing hemangiomas (PSH) may be not equally maturity, but this viewpoint needs more evidences.

AIM

To determine E-cadherin, beta-catenin and p120(ctn) expression phenotype in cuboidal and polygonal cells, which are the two major cell types in pulmonary sclerosing hemangiomas.

METHODS

Specimens were obtained from 25 patients with PSH and 8 patients with pulmonary inflammatory pseudotumors. The expression levels of E-cadherin, beta-catenin and p120(ctn) were detected using a streptavidin peroxidase (SP) immunohistochemical method.

RESULTS

E-cadherin, beta-catenin and p120(ctn) were expressed strongly on the cuboidal cell membranes, while beta-catenin was also expressed the cuboid cytoplams in 25 PSH patients. However, in the polygonal cell membranes, the expression levels of these molecules were decreased, and mainly cytoplamic. Specifically, E-cadherin, beta-catenin and p120(ctn) were expressed in both the cytoplasm and on the cell membranes in the intracavitary lining cells of the hemorrhagic regions. The expression phenotype in proliferating type II pneumocytes in the eight pulmonary inflammatory pseudotumors was similar to that in the cuboidal cells in PSH patients.

CONCLUSION

The cuboidal cells, resembling inflammatory proliferative type II pneumocytes, display several characteristics of epithelial cells, including normal expression of E-cadherin and catenin. Comparatively, polygonal cells are not as mature as cuboidal cells and lack of expression of E-cadherin and catenin.

Pneumocytic Adenomyoepithelioma: A Distinctive Lung Tumor With Epithelial, Myoepithelial, and Pneumocytic Differentiation

Pulmonary tumors with epithelial and myoepithelial differentiation are rare, thought to be of bronchial minor salivary gland origin and classified similarly to salivary gland neoplasms. We report a series of a distinctive subtype of pulmonary glandular tumors showing epithelial and myoepithelial differentiation with further pneumocytic specialization. All patients were women, aged 52 to 63 years and presented with single or multiple pulmonary nodules. The tumors were grossly circumscribed, 0.8 to 2.6 cm in greatest dimension, and histologically showed glandular and spindle cell differentiation. Some glands were filled with colloidlike secretion and had an inner, cuboidal epithelial cell layer (pankeratin, epithelial membrane antigen, and thyroid transcription factor-1 positive), surrounded by an outer layer of myoepithelial cells merging with foci of spindled myoepithelial cells (high molecular weight keratin, S100, smooth muscle actin, calponin, caldesmon, and p63 positive). There were also some glands lined by a single layer of plump cells that were positive for surfactant protein-A in addition to the other epithelial cell markers. Electron microscopy confirmed pneumocytic features in these cells and the myoepithelial nature of the spindled cells. The surgery in all cases was wedge resection of the masses. The biologic behavior to date has been benign. This is the first reported series of a distinctive lung tumor with epithelial, myoepithelial, and pneumocytic differentiation that differs histologically from all previously recognized pulmonary salivary gland-type and pneumocytic tumors. It is a unique benign appearing neoplasm for which the designation pneumocytic adenomyoepithelioma is suggested.

[Sclerosing hemangioma of the lung: a rare lesion with a difficult diagnosis]

Sclerosing hemangioma of the lung is a rare lesion described for the first time in 1956 by Liebow. We report a case in a 45 year-old woman who was admitted for exploration of chronic cough. The chest x-ray revealed a round opacity, well delimited in the left pulmonary parenchyma. Surgical resection enabled the histopathological diagnosis of sclerosing hemangioma. We review progress in our knowledge of the histogenesis and diagnosis of this tumor. Immunohistochemistry has been highly contributory although numerous points remain controversial.