Sclerosing hemangioma of the lung

Magnetic resonance imaging findings of pulmonary sclerosing pneumocytoma: a case report and literature review

Background

Pulmonary sclerosing pneumocytoma (PSP) is a rare lung tumor that is mostly isolated and commonly reported among middle-aged East Asian women. Recently, Immunohistochemistry (IHC) analysis has suggested that PSP is of primitive epithelial origin, most likely derived from type II alveolar air cells. Patients with PSP are generally asymptomatic and usually detected for other unrelated reasons during routine imaging. Several studies have already investigated the computed tomography (CT) features of PSP and their correlation with pathology. Magnetic resonance imaging (MRI) is a radiation-free imaging technique with important diagnostic value for specific pulmonary nodules. However, very few case reports or studies focus on the MRI findings of PSP.

Case report

We reported a case of an asymptomatic 56-year-old female with a solitary, well-defined soft-tissue mass in the lower lobe of the left lung. The mass showed iso-to-high signal intensity (SI) than muscle on T1-weighted image (T1WI) and T2-weighted image (T2WI) and a much higher SI on fat-suppressed T2WI, diffusion-weighted image, and apparent diffusion coefficient image. Contrast-enhanced fat-suppressed T1WI revealed noticeable inhomogeneous progressive enhancement throughout the mass. The mass revealed early enhancement without a significant peak, followed by a plateau pattern on dynamic contrast-enhanced MRI images. The patient underwent left basal segmentectomy via thoracoscopic surgery. Histopathology and IHC results of the surgical specimen confirmed that it was a PSP. We concluded that the MRI findings of PSP might adequately reflect the different components within the tumor and aid clinicians in preoperative diagnosis and assessment. To the best of our knowledge, this is the most comprehensive case report on the MRI findings of PSP.

Conclusion

The MRI findings of PSP correspond to its histopathological features. Here, we present a case of PSP with the most comprehensive MRI findings, emphasizing the importance of multiple-sequence MRI in diagnosing PSP.

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.

Analysis of the value of enhanced CT combined with texture analysis in the differential diagnosis of pulmonary sclerosing pneumocytoma and atypical peripheral lung cancer: a feasibility study

BACKGROUND

As a rare benign lung tumour, pulmonary sclerosing pneumocytoma (PSP) is often misdiagnosed as atypical peripheral lung cancer (APLC) on routine imaging examinations. This study explored the value of enhanced CT combined with texture analysis to differentiate between PSP and APLC.

METHODS

Forty-eight patients with PSP and fifty patients with APLC were retrospectively enrolled. The CT image features of the two groups of lesions were analysed, and MaZda software was used to evaluate the texture of CT venous phase thin-layer images. Independent sample t-test, Mann-Whitney U tests or χ² tests were used to compare between groups. The intra-class correlation coefficient (ICC) was used to analyse the consistency of the selected texture parameters. Spearman correlation analysis was used to evaluate the differences in texture parameters between the two groups. Based on the statistically significant CT image features and CT texture parameters, the independent influencing factors between PSP and APLC were analysed by multivariate logistic regression. Extremely randomized trees (ERT) was used as the classifier to build models, and the models were evaluated by the five-fold cross-validation method.

RESULTS

Logistic regression analysis based on CT image features showed that calcification and arterial phase CT values were independent factors for distinguishing PSP from APLC. The results of logistic regression analysis based on CT texture parameters showed that WavEnHL_s-1 and Perc.01% were independent influencing factors to distinguish the two. Compared with the single-factor model (models A and B), the classification accuracy of the model based on image features combined with texture parameters was 0.84 ± 0.04, the AUC was 0.84 ± 0.03, and the sensitivity and specificity were 0.82 ± 0.13 and 0.87 ± 0.12, respectively.

CONCLUSION

Enhanced CT combined with texture analysis showed good diagnostic value for distinguishing PSP and APLC, which may contribute to clinical decision-making and prognosis evaluation.

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.

Pulmonary Sclerosing Pneumocytoma: A Pre and Intraoperative Diagnostic Challenge. Report of Two Cases and Review of the Literature

Pulmonary sclerosing pneumocytoma is a rare benign pulmonary tumor of primitive epithelial origin. Because of the unspecific radiological features mimicking malignancies and its histological heterogeneity, the differential diagnosis with adenocarcinoma and carcinoid tumors is still challenging. We report our experience of two cases of sclerosing pneumocytoma, as well as a review of the literature. Immunohistochemical findings showed intense staining of the cuboidal epithelial cells for cytokeratin-pool and TTF-1, with focal positivity for progesterone receptors. Round and spindle cells expressed positivity for vimentin, TTF-1 and focally for the progesterone receptor. Cytologic diagnosis of pulmonary pneumocytoma requires the identification of its dual cell population, made up of abundant stromal cells and fewer surface cells. Since the pre- and intraoperative diagnosis should guide surgical decision making, obtaining a sufficient specimen size to find representative material in the cell block is of paramount importance.

68Ga-DOTATATE-avid pulmonary sclerosing pneumocytoma in a man of North African descent: Case report, imaging findings and pathology

Pulmonary sclerosing pneumocytoma (PSP) is a benign tumor originating from primitive respiratory epithelium which tends to present as an asymptomatic solitary lesion in the periphery of the lung. It primarily occurs in women, with a 5:1 ratio of female to male, and in East Asian populations. We describe a rare case of a gallium-68 (⁶⁸Ga)-DOTATATE avid PSP in a middle-aged man of North African ancestry. Contrast-enhanced computed tomography (CT) revealed an enhancing ovoid 2-cm solid lesion within the periphery of the left upper lobe abutting the superior portion of the lateral left ventricular wall. A fluorine-18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) demonstrated low-level FDG uptake, but a ⁶⁸Ga-DOTATATE PET/CT showed avid tracer uptake, concerning for a carcinoid tumor. The lesion was surgically excised, and the histopathologic analysis revealed the typical morphologic and histochemical markers of a PSP. We conclude that, although rare, PSP can be a differential consideration when evaluating a ⁶⁸Ga-DOTATATE-avid solitary lung nodule concerning for carcinoid tumor, in all genders and in ethnicities other than East Asian.

Expression of ALDH and SOX-2 in Pulmonary Sclerosing Pnemocytoma (PSP) of the Lung: Is There a Meaning Behind?

Background: Pulmonary sclerosing pneumocytoma (PSP) is a rare benign pulmonary tumor that derives from primitive respiratory epithelium of the pulmonary alveolus. The etiology and pathogenesis are still unclear. Histopathological diagnosis focuses on cells that are positive for TTF1, EMA, cytokeratin-7, and CAM 5.2. The aim of our study is to highlight the elevated expression of ALDH and the presence of SOX-2 in pulmonary sclerosing pneumocytoma.

Methods: We report five cases of pulmonary sclerosing pneumocytoma undergone surgery at our Division of Thoracic Surgery, during a period between 1994 and 2011. ALDH and SOX-2 markers were also tested for positivity in all the patients.

Results: Patients showed elevated expression of ALDH during immunohistochemistry and mild expression of SOX-2, although in two cases in which SOX-2 was highly expressed. Among these two patients, one presented with lymph node recurrence while the other had no recurrence with a PET-positive nodule. In particular, the patient who had developed recurrence had an ALDH score of 4 and a SOX-2 score of 3, whereas the patient with the PET-positive nodule showed an ALDH score of 4 with a mild SOX-2 expression of score 1.

Conclusions: This is the first attempt demonstrating the elevated expression of ALDH in this disease. SOX-2 expression was noted in both the patient who developed recurrence and the patient with a PET-positive nodule. We believe that further investigation may be highly useful to better characterize these two markers as well as understand their function.

Pulmonary sclerosing pneumocytoma: Cytomorphology and immunoprofile

BACKGROUND

Sclerosing pneumocytoma (SP) is a rare, benign pulmonary neoplasm. To the authors' knowledge, the current study is the first to evaluate the cytomorphology and immunoprofile of SP in a series.

METHODS

A total of 9 fine-needle aspiration cases of SP (7 of which were computed tomography guided and 2 of which were endobronchial ultrasound guided) including histopathology and immunohistochemistry were collected from 5 institutions.

RESULTS

The female-to-male ratio was 3.5:1, and the mean age of the patients was 54 years (range, 27-73 years). All cases presented as lung nodules, with a mean size of 2.2 cm (range, 1.1-5 cm), and were interpreted as atypical on rapid on-site evaluation. The final diagnoses were favor adenocarcinoma (1 case), well-differentiated lung adenocarcinoma (2 cases), low-grade epithelial neoplasm (2 cases), and sclerosing pneumocytoma (4 cases). Samples were moderately cellular, and consisted of round epithelioid cells with clear cell features, columnar cells, and spindle cells. A papillary arrangement with prominent hyalinized fibrovascular cores was the most common architectural pattern, followed by flat sheets and acinar formations. Tumor cells demonstrated mild, focally moderate nuclear pleomorphism with prominent nucleoli, hyperchromasia, nuclear elongation, nuclear overlap, and occasional nuclear inclusions and grooves. The background consisted of foamy macrophages (9 cases), hemosiderin pigment (6 cases), and lymphoid aggregates (3 cases) with no mitoses and/or necrosis. The surface cells and underlying round cells were positive for both thyroid transcription factor 1 and epithelial membrane antigen in all cases, which was the most notable immunohistochemical finding.

CONCLUSIONS

Cytomorphological findings of SP overlap with those of well-differentiated lung adenocarcinoma. Awareness of these cytomorphologic findings and the distinct immunoprofile of the 2 cell types found in SP should prevent a misdiagnosis and aggressive treatment.

Sclerosing pneumocytoma mixed with a typical carcinoid tumor: A case report and review of literature

RATIONALE

Sclerosing pneumocytoma accompanied with other type of tumor in one patient is very rare. Here, we report a case of a sclerosing pneumocytoma mixed with a typical carcinoid tumor in a same neoplasm.

PATIENT CONCERNS

A 55-year-old woman incidentally detected a space-occupying lesion of right lung in routine health examination. The patient was asymptomatic and there were no positive findings in routine laboratory examination, physical examination, and pulmonary function test. Computed tomography revealed a solitary round mass in the middle lobe of the right lung.

DIAGNOSIS

The lesion was diagnosed as a sclerosing pneumocytoma accompanied with a typical carcinoid tumor of the right lung.

INTERVENTION

The patient underwent thoracoscopic lobectomy in our hospital.

OUTCOMES

The postoperative course was uneventful.

LESSONS

This case is rare and noteworthy for a lesion containing two different types of neoplasms, which may cause diagnostic difficulties.

A case of pulmonary sclerosing pneumocytoma in the hilar lesion

Pulmonary sclerosing pneumocytoma (PSP) arising from the hilar lesion is extremely rare. We report an asymptomatic 70-year-old female with a thoracic tumor of unknown origin. Contrast-enhanced chest tomography showed a poorly and heterogeneously enhanced 40-mm tumor compressing the left upper lobe, bronchus, and pulmonary arteries. Positron-emission tomography did not detect abnormal integration in the tumor. Surgical resection was planned to confirm diagnosis and avoid further compression on the structures. Intraoperative findings revealed a dark red-colored tumor, projecting from the left upper lobe in the hilar lesion. Left upper lobectomy was performed through video-assisted thoracoscopic surgery to achieve complete resection and avoid contact bleeding. Immunohistochemical examination revealed the presence of PSP.

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.

A 33-Year-Old Woman With a Fluorodeoxyglucose-Avid Left Lower Lobe Mass

A 33-year-old woman of Latin American origin was referred to our department by her primary care physician for a left lower lobe mass, which was incidentally found on a CT scan of her abdomen. The patient had complaints of abdominal pain for which she underwent imaging of her abdomen. Review of systems was negative for any respiratory complaints, and she denied any history of cigarette smoking or recreational drug use.

Application of Immunohistochemistry in the Diagnosis of Pulmonary and Pleural Neoplasms

CONTEXT

- A vast majority of neoplasms arising from lung or pleura are initially diagnosed based on the histologic evaluation of small transbronchial, endobronchial, or needle core biopsies. Although most diagnoses can be determined by morphology alone, immunohistochemistry can be a valuable diagnostic tool in the workup of problematic cases.

OBJECTIVE

- To provide a practical approach in the interpretation and immunohistochemical selection of lung/pleura-based neoplasms obtained from small biopsy samples.

DATA SOURCES

- A literature review of previously published articles and the personal experience of the authors were used in this review article.

CONCLUSION

- Immunohistochemistry is a useful diagnostic tool in the workup of small biopsies from the lung and pleura sampled by small biopsy techniques.

Pneumocytoma (sclerosing hemangioma), a potential pitfall

Pneumocytoma is an uncommon benign tumor of the lung, derived from primitive respiratory epithelium, with a predilection for middle-aged females. A single, well-circumscribed mass is commonly identified on imaging, necessitating pathologic evaluation for further assessment. Fine-needle aspiration cytology is a minimally invasive and cost-effective method that can be utilized in the diagnosis of these lesions. Yet, distinction of pneumocytoma from other entities such as well-differentiated adenocarcinoma or carcinoid tumor can be quite challenging. Herein, we describe a case initially misdiagnosed as lung adenocarcinoma on FNA that was proven to be pneumocytoma on subsequent resection. This report highlights the importance of recognizing key cytologic features of pneumocytoma, namely the papillary architecture, dual cell population, and the hemorrhagic background with foamy macrophages, among others. An accurate preoperative diagnosis of this entity provides optimal patient management, as conservative surgical excision is curative. Diagn. Cytopathol. 2017;45:744-749. © 2017 Wiley Periodicals, Inc.

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.

Pulmonary sclerosing pneumocytoma of the lung: CT characteristics in a large series of a tertiary referral center

The purpose of this study is to describe the detailed clinical, chest computed tomography (CT), and F-fluorodeoxyglucose positron emission tomography (FDG PET) characteristics of the tumor boundary for the diagnosis and investigate the outcome of pulmonary sclerosing pneumocytoma (PSP) using confirmed large data of a tertiary referral center. Confirmed 76 patients were included. We evaluated the findings of CT including 4 CT signs, FDG PET, and histopathology. Most patients had a single lesion (92.1%), smooth boundary (65.8%), and oval shape (65.8%) and the mean diameter was 22.7 mm. The CT signs included marginal pseudocapsule (50%), overlying vessel (26.3%), air gap (2.6%), and halo sign (17.1%). A predominantly solid was the most common histopathologic type. The mean maximum standardized uptake value on FDG PET of 17 patients was 1.8 (range, near 0 or normal tissue metabolism ∼2.9). PSP should be considered in middle-aged women whose CT features show incidental nodule(s), commonly with surrounding ground-glass opacity and characteristic CT signs of the tumor boundary, and hypometabolic uptake on FDG PET. Outcome of patients is excellent.

Multiple pulmonary sclerosing hemangiomas (pneumocytoma) mimicking lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

Pulmonary sclerosing hemangioma (PSH), or the alternative name of “sclerosing pneumocytoma,” is a rare benign neoplasm. PSH is often asymptomatic and presents as a solitary or multiple pulmonary nodules on radiologic imaging studies. Few articles have been reported to describe the fluorodeoxyglucose positron emission tomography (FDG PET) findings about PSH. The authors describe an interesting but uncommonly encountered cause of false positive FDG PET scan in the thorax in a 25-year-old woman, a known case of arteriovenous malformation of oral cavity who underwent embolization and presented with incidental detection of bilateral lung nodules. She is asymptomatic and is on follow-up.

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.

Primary lung and large airway neoplasms in children: current imaging evaluation with multidetector computed tomography

Multidetector computed tomography (MDCT) offers an important noninvasive imaging modality for confirmation and further characterization of primary lung and large airway neoplasms encountered in pediatric patients. Children represent a unique challenge in imaging, not only because of unique patient factors (eg, inability to follow instructions, motion, need for sedation) but because of the technical factors that must be optimized to reduce radiation dose. This article reviews an MDCT imaging algorithm, up-to-date imaging techniques, and clinical applications of MDCT for evaluating benign and malignant primary neoplasms of lung and large airway in infants and children.

A hepatic sclerosed hemangioma with significant morphological change over a period of 10 years: a case report

INTRODUCTION

Liver cavernous hemangioma is the most common noncystic hepatic lesion, and a hemangioma that undergoes degeneration and fibrous replacement is called a hepatic sclerosed hemangioma.

CASE PRESENTATION

A 63-year-old Japanese man was admitted for detailed investigation of a liver tumor. Tumor markers carcinoembryonic antigen, alpha-fetoprotein, and CA19-9 levels in the peripheral blood were not elevated at any time. Plain computed tomography showed an approximately 1.5 cm low density mass in the periphery of segment 8, which was marginally enhanced on contrast-enhanced dynamic computed tomography. On magnetic resonance imaging, the tumor was hypointense on T1-weighted image and hyperintense on T2-weighted image. The tumor was suspected to be an atypical hemangioma, metastatic, hepatocellular carcinoma, or cholangiocellular carcinoma. Segmental hepatectomy was performed. Histological examination of the resected tumor specimen revealed a sclerosed hemangioma with marked hyalinization and sparse stromal fibrosis. Immunochemically, the tumor cells were positive for CD34 and alpha smooth muscle actin. Electron microscopically, the residual hemangioma consisted of numerous caveolae and vesicles in endothelial cells in irregular shapes and sizes. Immunostaining for caveolin-1 showed decreased or no caveolin-1 reactivity in the hyalinized lesions of the sclerosed hemangioma, but abundant caveolin-1 reactivity in the residual cavernous hemangioma. Of interest, computed tomography images of the tumor obtained 10 years earlier at our hospital depicted a 3 cm typical cavernous hemangioma.

CONCLUSIONS

Hepatic sclerosed hemangioma is a rare condition. Comparison of radiological findings of the lesion over a period of 10 years was valuable in providing insight for the evolutional process from liver cavernous hemangioma to hepatic sclerosed hemangioma.

Rare pleural tumors

Primary pleural tumors other than mesothelioma account for fewer than 1% of all lung cancers, and consequently they pose diagnostic and management challenges. Their treatment must be targeted toward the specific tumor type and is often quite different from the treatment for mesothelioma or metastases. Despite the best efforts at diagnosing and treating these tumors, the prognosis associated with some of the benign and many of the malignant variants of these tumors remains poor. In this review, we describe the radiologic and pathologic features of the less common primary pleural tumors and propose a diagnostic approach to their evaluation.

Synchronous sclerosing haemangiomas of the lung: an unusual presentation of a rare tumour

Pulmonary sclerosing haemangioma  is a rare lung tumour with a preponderance for Asian oriental women. Typically a well-circumscribed, solitary lesion with benign characteristics, there are concerns of malignant potential including regional lymph node metastases. Four histological subtypes exist. Diagnosis can be challenging as patients are usually asymptomatic and radiological findings are non-specific. Surgical resection alone is diagnostic and therapeutic. We present a case of this rare tumour with an uncommon presentation as two synchronous tumours initially misdiagnosed as a pulmonary adenocarcinoma.

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.

Usefulness of Ki-67 (MIB-1) immunostaining in the diagnosis of pulmonary sclerosing hemangiomas

Pulmonary sclerosing hemangioma (PSH) is an uncommon lung neoplasm with a clinical outcome that is generally benign. However, differentiating PSH from pulmonary carcinoma is sometimes difficult as both lesions share similar histopathologic and immunohistochemical features. In this study, we investigated the usefulness of Ki-67 (MIB-1) immunostaining in the diagnosis of PSH. We compared the staining pattern for Ki-67 (MIB-1) in 29 cases of typical PSH and 79 cases of pulmonary non-small cell carcinoma (NSCLC) using an immunohistochemical method on formalin-fixed paraffin-embedded tissues. In all studied PSH cases, we noted cell membrane and cytoplasmic staining for Ki-67 (MIB-1), but this was not observed in any of the NSCLC cases. The Ki-67 proliferation index was lower in PSH than in the NSCLC cases (mean, 1.1% vs mean, 5.5%; p < 0.001). These findings suggest that cell membrane and cytoplasmic staining for Ki-67 (MIB-1), as well as the Ki-67 proliferation index, may be useful for distinguishing PSH from pulmonary carcinoma.

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.

[Diagnosis and treatment for pulmonary sclerosing hemangioma]

背景与目的

肺硬化性血管瘤(pulmonary sclerosing hemangioma, PSH)概念的提出迄今只有50余年，是一种少见的肺部良性疾病。PSH临床表现有一定特点，需与肺癌鉴别诊断。本文总结我院48例PSH的临床诊治经验并复习文献，旨在提高对PSH的认识，探讨合理的诊断与治疗手段。

方法

2001年1月-2011年4月共收治PSH 48例，结合文献报道总结分析PSH的发病特点、临床表现、影像学、病理学特点及预后。

结果

全组48例，无症状者27例(56.3%)，肿物大小0.2 cm-7.0 cm，平均2.1 cm，各个肺叶均有发生。合并肺门或纵隔淋巴结肿大者15例(31.3%)。手术47例，其中肺叶部分切除29例(61.7%)，肺叶切除14例(29.8%)，肿物剔除3例(6.4%)，前纵隔肿物切除者1例(2.1%)。47例术后均无复发。CT引导下穿刺活检诊断1例，随访28个月未见肿瘤进展。

结论

PSH术前定性诊断困难，手术既是确诊手段又是有效的治疗手段，该病预后良好。

Fatal hemothorax caused by pseudomesotheliomatous carcinoma of the lung

We present a case of a poorly differentiated pseudomesotheliomatous carcinoma originating in the lung, which was manifested with the distinctly rare complication of massive true hemothorax and persistent blood loss that proved rapidly fatal in spite of surgery. Pseudomesotheliomatous carcinoma of the lung and neoplasia-associated hemothorax are reviewed and discussed.

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.

Comparison of genetic and epigenetic alterations at 11 tumor suppressor loci in pulmonary sclerosing hemangioma and adenocarcinoma

Pulmonary sclerosing hemangioma (SH) is an unusual tumor of pneumocytic origin. Morphologically, SH can mimic pulmonary adenocarcinomas. Here, the authors compared genetic and epigenetic aberrations in SH with those in pulmonary adenocarcinoma. Clinicopathologic characteristics, microsatellite alterations, and CpG island methylation were analyzed in pulmonary SHs (n = 24) and adenocarcinomas (n = 34) to compare their patterns of molecular abnormalities. SHs were also analyzed immunohistochemically to characterize the expression status of proteins involved in basic biologic processes. The clinical presentation of SH cases was generally benign. Both cell types of SH stained positive for thyroid transcription factor 1 (TTF-1), epithelial membrane antigen (EMA), β-catenin, E-cadherin, and vascular endothelial growth factor (VEGF). Allelic imbalances in D3S1283, D3S1234, D3S1300, D3S1285, TP53, D17S938, and D9S179 were less frequent in SH than in adenocarcinoma; rates of allelic imbalances in D20S170 and D21S1446 were not significantly different. In SH, CpG island methylation frequencies of p16(INK4a) (0.0%) and RASSF1A (12.5%) were significantly lower than those in adenocarcinoma (29.4% and 38.2%, respectively); the frequencies of HOX D9, D11, and D13 gene methylation in SH were 37.5%, 33.3%, and 33.3%, respectively. The results show that pulmonary SH and adenocarcinoma share similar genetic and epigenetic aberrations, but also exhibit significant differences, especially in tumor suppressor genes.

Multiple FDG-avid sclerosing hemangiomas mimicking pulmonary metastases in a case of soft tissue sarcoma

Non-neoplastic lesions have been known to mimic malignancies and metastases on positron emission tomography/computed tomography. We report the rare occurrence of multiple fluorodeoxyglucose-concentrating sclerosing hemangiomas in a patient with soft tissue sarcoma mimicking lung metastases.