Diagnosis: Sclerosing hemangioma (synonym: sclerosing pneumocytoma)


Sclerosing Hemangioma

Introduction: This rare, benign tumor was originally believed to be a proliferation of blood vessels similar to sclerosing hemangioma in the skin [1-3]. Immunohistochemical and electron microscopic studies have shown that the tumor cells have epithelial features, and the term "sclerosing pneumocytoma" has been proposed (but little used) as a better name [4].

Clinical features: The tumor occurs in persons 15 y or older (mean 44 y), predominantly in women (F/M: 5.3/1). Most patients are asymptomatic, but cough, chest pain, or hemoptysis can occur [3-5].

Radiographic changes: The lesions are solitary, sharply-defined, rounded opacities up to 8 cm in diameter (mean 3 cm) [3]. In one series, 2 of 49 cases had 2 or more nodules [3], and in another report, multiple nodules up to 2.7 cm were present in the right lower lobe [6]. Lesions have been noted on radiographs taken up to 14 y before surgery [3]. Calcification may be present [3].

Gross features: Tumors are firm, circumscribed, and non-encapsulated. The cut surface varies from white to yellow to red [3]. More than half of tumors occur in the lower lobes [3,4]. Regional lymph node metastasis has been reported in one case [7].

Histologic features: The histologic changes already described indicate that the cells covering papillae show respiratory or type II cell differentiation and that the round cells beneath them are less differentiated [8,9]. Inflammatory cells may be scattered throughout, and granulomas have been described [3,10].

Immunohistochemical features: The surface cells react strongly with antibodies to epithelial markers (keratin, Clara cell antigen, and surfactant apoprotein). The round cells tend to be negative for these markers. Neither of the cell types reacts with endothelial cell markers [4,9,11]. A recent study has shown that both the surface and underlying round cells usually react with an antibody to an epithelial marker (EMA) and thyroid transcription factor-1 (TTF-1), which is also found in fetal lung epithelium before the development of Clara cell and surfactant proteins. The TTF-1 reactivity (and lack of Clara cell and sufactant proteins) suggests that the tumor cells show the differentiation of primitive, rather than adult, respiratory epithelium [12]. TTF-1 is not diagnostic of sclerosing hemangioma as other tumors also react with this antibody. Despite some differences in immunohistochemical reactivity of surface and underlying round cells, both cell types are thought to be neoplastic [12].

Ultrastructural features: Lining cells are mostly typical type II cells or Clara cells. The round cells have interdigitating cell processes, focal long microvilli, and immature lamellar bodies of type II cell differentiation [8,11,12].

Summary of Histologic Patterns

Cytologic diagnosis: Recognition of uniform cells attached to fibrous stroma, blood-filled spaces, papillary arrangements, or hemosiderin-filled macrophages in smears or cell blocks of fine needle aspirates can be diagnostic [5]. Nevertheless, even if sclerosing hemangioma is considered, cytologic diagnosis is difficult, and in this particular case, a specific diagnosis was not made before the lesion was excised.

Differential diagnosis: Histologically, the tumors can be confused with primary bronchioloalveolar carcinoma (cells line papillary processes but do not fill cores), carcinoid tumor (chromogranin positive), or well-differentiated metastatic tumors (e.g. thyroid or renal carcinoma or melanoma) [5].

References

1. Liebow A, Hubbell D. Sclerosing hemangioma (histiocytoma, xanthoma) of the lung. Cancer 1956; 9:53-75.

2. Sugio K, Yokoyama H, Kaneko S, Ishida T, Sugimachi K. Sclerosing hemangioma of the lung: radiographic and pathological study. Ann Thorac Surg 1992; 53:295-300.

3. Katzenstein A-L, Gmelich J, Carrington C. Sclerosing hemangioma of the lung. A clinicopathologic study of 51 cases. Am J Surg Pathol 1980; 4:343-356.

4. Yousem S, Wick M, Singh G, Katyal S, Manivel J, Mills S, Legier J. So-called sclerosing hemangiomas of lung. An immunohistochemical study supporting a respiratory epithelial origin. Am J Surg Pathol 1988; 12:582-590.

5. Wojcik E, Sneige N, Lawrence D, Ordóñez N. Fine-needle aspiration cytology of sclerosing hemangioma of the lung: case report with immunohistochemical study. Diagn Cytopathol 1993; 9:304-309.

6. Noguchi M, Kodama T, Morinaga S, Shimosato Y, Saito T, Tsuboi E. Multiple sclerosing hemangiomas of the lung. Am J Surg Pathol 1986; 10:429-435.

7. Tanaka I, Inoue M, Matsui Y, Oritsu S, Akiyama O, Takemura T, Fujiwara M, et al. A case of pneumocytoma (so-called sclerosing hemangioma) with lymph node metastasis. Japan J Clin Oncol 1986; 16:77-86.

8. Katzenstein A-L, Weise D, Fulling K, Battifora H. So-called sclerosing hemangioma of the lung. Evidence for mesothelial origin. Am J Surg Pathol 1983; 7:3-14.

9. Barbareschi M, Colombetti V, Ferrero S, Yousem S, Singh G. Sclerosing haemangioma of the lung. Histol Histopath 1992; 7:209-212.

10. Moran CA, Zeren H, Koss MN. Sclerosing hemangioma of the lung. Granulomatous variant. Arch Pathol Lab Med 1994; 118:1028-1030.

11. Satoh Y, Tsuchiya E, Weng S-Y, Kitagawa T, Matsubara T, Nakagawa K, Kinoshita I, et al. Pulmonary sclerosing hemangioma of the lung. A type II pneumocytoma by immunohistochemical and immunoelectron microscopic studies. Cancer 1989; 64:1310-1317.

12. Devouassoux-Shisheboran M, Hayashi T, Linnoila R, Koss M, Travis W. A clinicopathologic study of 100 cases of pulmonary sclerosing hemangioma with immunohistochemical studies. TTF-1 is expressed in both round and surface cells, suggesting an origin from primitive respiratory epithelium. Am J Surg Pathol 2000; 24:906-916. Abstract

Clinical summary

Comments: mw6825@itsa.ucsf.edu

Table of Contents

Last revised 10/20/02

Copyright 1997 Martha L. Warnock. All rights reserved.