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.

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.

Segmentectomy for giant pulmonary sclerosing haemangiomas with high serum KL-6 levels.

We describe a 61-year old female patient with a giant pulmonary sclerosing haemangioma (PSH) and an extremely high preoperative serum KL-6 level. During an annual health screening, the patient showed a posterior mediastinal mass on chest radiography. Chest computed tomography and magnetic resonance imaging revealed a well-circumscribed 60 mm diameter nodule with a marked contrast enhancement in the left lower lobe. The preoperative serum KL-6 level was elevated to 8204 U/ml. We performed a four-port thoracoscopic basal segmentectomy and lymph node sampling for diagnosis and therapy. The postoperative diagnosis showed PSH. The serum KL-6 level decreased dramatically with tumour resection. To the best of our knowledge, this is the first report of a patient with PSH showing a high serum KL-6 level.

Clinicopathological analysis of pulmonary sclerosing hemangioma.

BACKGROUND: Sclerosing hemangiomas of the lung are uncommon tumors and are thought to be benign. However, the histogenesis and clinicopathological features of these tumors have not been elucidated. METHODS: We analyzed the clinicopathological features of 26 sclerosing hemangiomas. The immunoreactivity for Ki-67 and p53 of sclerosing hemangiomas was determined and compared with that of pathological stage 1 pulmonary papillary adenocarcinomas. RESULTS: The patients of sclerosing hemangioma were predominantly female. Eighteen patients were detected as a result of routine medical examinations and 15 were nonsmokers. Seven patients underwent tumor enucleation, 10 underwent a wedge resection, and 9 underwent a lobectomy. The mean tumor size was 2.2 cm (range 1 to 5 cm). Pathological findings demonstrated a papillary pattern in 23 cases, sclerotic pattern in 26 cases, hemorrhagic pattern in 22 cases and a solid pattern in 25 cases. Twenty-five cases had an excellent prognosis with no evidence of recurrence following surgery. However, 1 patient who had undergone a wedge resection developed a local recurrence and required an additional wedge resection. The Ki-67 labeling index of sclerosing hemangiomas was significantly lower than that of adenocarcinomas, whereas the Ki-67 labeling index of the recurrent case was 0.4%. No significant immunohistochemical staining for p53 was observed in sclerosing hemangioma cases. CONCLUSIONS: Sclerosing hemangioma exhibits various histologic findings. Although we experienced one case with a recurrent tumor, sclerosing hemangiomas did not exhibit malignant behavior.