Cytopathologic diagnosis of pulmonary sclerosing hemangioma

A case report on incidentally detected pulmonary sclerosing pneumocytoma: a diagnostic challenge

Introduction and importance

Pulmonary sclerosing pneumocytoma (PSP) is a rare non-cancerous lung tumor that is usually asymptomatic, but may cause respiratory distress if it becomes large. PSPs are often detected incidentally because of their slow growth, lack of symptoms, characteristic radiographic features, and increased use of imaging studies. Although it is not a malignant tumor, it can mimic malignancy on imaging and histology, leading to misdiagnosis and unnecessary surgery.

Case presentation

A 23-year-old asymptomatic female was incidentally diagnosed with PSP during evaluation for a breast fibroadenoma. A chest CT revealed a 3 cm lobulated mass in the left upper lobe. Cytology showed malignant cells with necrotic debris. Immunohistochemistry was positive for TTF-1 and EMA, negative for p63 and AE1/AE3. Histopathology confirmed a well-circumscribed benign neoplasm, consistent with pulmonary sclerosing pneumocytoma. There was no mediastinal lymph node invasion, and the post-surgery prognosis was good.

Clinical discussion

PSP is a slow-growing tumor that is often asymptomatic until it reaches a significant size. Owing to their well-circumscribed margins and the presence of calcifications, they are often detected incidentally during imaging studies, such as routine chest radiography or CT scans for unrelated conditions. Although these tumors are often incidental, it is important to diagnose and treat them appropriately to prevent potential complications and malignant transformation.

Conclusion

The findings of this study contribute to the existing literature, increase awareness of this rare tumor, and provide insights into its diagnosis, treatment, and follow-up.

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.

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.

[On the histo- and morphogenesis of sclerosing pneumocytoma and its diagnostic criteria]

The paper presents the data available in the literature on the pathogenesis, clinical and morphological, histological and immunohistochemical features of pulmonary sclerosing pneumocytoma (SP). The paper gives the detailed histological and immunohistochemical characteristics of 6 SP cases. The need for the differential diagnosis of SP is determined by the features and complexity of their histo- and morphogenesis within a single tumor and a complex diagnostic study.

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.

A Comparative Study of Intraoperative Cytology and Frozen Sections of Sclerosing Pneumocytoma

Sclerosing pneumocytoma (SP) is a rare benign neoplasm of the lung. Conservative surgical excision is curative with an excellent prognosis. Preoperative diagnosis of SP can be difficult. Thus, intraoperative frozen sections play a crucial role in guiding surgical management. However, the interpretation of frozen section can be challenging due to freezing artifact. Intraoperative cytology provides a complementary and better morphological detail. In this study, we review and compare the intraoperative cytology and frozen section of 14 cases of SP. SP is characterized by containing 2 cell types: round stromal cells and cuboidal surface cells. The round stromal cells were small with uniform nuclei and inconspicuous nucleoli. The cuboidal surface cells were more differentiated into type II pneumocytes and showed slightly larger in size with intranuclear inclusions. The immunocytochemical double-labeling staining could display 2 distinct population of vimentin-positive round stromal cells and cytokeratin 7-positive cuboidal surface cells. Recognition of the cytological features of SP circumvents the frozen section artifact and is a useful adjunct to the frozen section in leading to the correct diagnosis of SP.

Pitfalls and Key Features of a Case of Sclerosing Pneumocytoma: A Cytological Challenge?

BACKGROUND

The aim of the current case report is to re-evaluate the key features and pitfalls of fine-needle aspiration cytology (FNAC) in the diagnosis of sclerosing pneumocytoma (previously named sclerosing hemangioma) and to establish the importance of FNAC in addressing a proper surgical strategy.

CASE

Herein we documented a case of a 70- year-old man with a lung nodule which showed a hypermetabolic uptake on positron emission tomography. He therefore underwent FNAC under computed tomography scan guidance with a 22-gauge needle. The cytopathological examination allowed a diagnosis of sclerosing pneumocytoma. A wedge surgical excision was performed and the histological examination confirmed the cytological diagnosis.

CONCLUSION

FNAC is a fundamental tool for distinguishing sclerosing pneumocytoma from a malignant lung tumour and together with clinical, radiological and pathological multidisciplinary assessment is indispensable in planning appropriate surgical management. Cytopathologists should be aware of the pitfalls and key features of the cytopathological diagnosis of sclerosing pneumocytoma, which can significantly change the surgical approach to the patient and protect him from aggressive overtreatment.

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.

Fine-needle aspiration diagnosis of sclerosing hemangioma (pneumocytoma): report of a case and review of the literature

Sclerosing hemangioma (pneumocytoma) is a rare benign lung tumor with uncertain histogenesis but characteristic histology. Reports of the cytopathology of this tumor are even rarer with only a handful of cases in the literature--many of these incorrectly diagnosed by cytology initially. Herein, we describe a case of sclerosing hemangioma diagnosed prima facie by fine-needle aspiration cytology. A cell block preparation with accompanying immunohistochemistry was instrumental in making the diagnosis. A review of the literature is also presented.

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.

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.

["Pneumocytoma" or "sclerosing hemangioma": histogenetic aspects of a rare tumor of the lung]

Aspects of histogenesis and nomenclature of so called "sclerosing hemangioma" of the lung (WHO 1999) are discussed and compared with immunohistochemical findings in eight examined operation specimen. The lesion is characterised by the presence of typical surface cells, which can be related to type II pneumocytes. Progesterone-receptor positive stromal cells may derive from primitive mesenchymal cells. Endothelial proveniance of tumor cells could not be confirmed by immunohistochemistry. Therefore, this rare usually benign pulmonary neoplasm should be entitled "pneumocytoma" analogous to the suggestion of several other authors.

Endobronchial variant of sclerosing hemangioma of the lung: histological and cytological features on endobronchial material

We report two cases of a rare presentation of pulmonary sclerosing hemangioma as an endobronchial polyp resulting in clinical symptoms of bronchial obstruction. We describe the histological and cytological description of this entity based on material obtained during bronchoscopic examination. In both cases, bronchoscopy revealed a polypoid mass protruding into the left lower lobar bronchus, with a smooth and hemorrhagic surface, reminiscent of a carcinoid tumor. On bronchial washing in case 1, numerous small round cells were seen with uniform nuclei and inconspicuous nucleoli, arranged in clusters with a pavement-type pattern and papillary configuration. The presence of a few reactive pneumocytes gives a dual cell proliferation, in a background of numerous foamy macrophages. Although the four architectural patterns of sclerosing hemangioma were present in the resected tumors, the papillary and solid patterns predominated in the endobronchial component of the tumors and these were seen on the bronchial biopsies. Recognition of the papillary pattern, the typical round cells coexpressing thyroid transcription factor-1 and epithelial membrane antigen without cytokeratin immunoreactivity, are helpful clues for the diagnosis on bronchial biopsy. Finally, hopefully awareness by clinicians and pathologists that sclerosing hemangioma can present as an endobronchial mass will facilitate diagnosis when this rare event occurs.