INTRODUCTION:Sclerosing hemangioma of the lung is a rare, benign neoplasm of the lung first described in 1956 by Liebow and Hubbell. Their initial interpretation of predominantly hemorrhagic blood-filled spaces led them to believe this was a hemangioma. Immunohistochemical staining has clarified its origin as primitive epithelial cells, specifically Type II pneumocytes.
CASE PRESENTATION:A 21 year-old female with a history of asthma and positive PPD was evaluated for a lung mass. This mass was noted six years prior upon evaluation for a positive PPD. She was asymptomatic, and it was felt the mass was secondary to a coccidioma. She was a lifelong nonsmoker who had spent 5 years in Southeast Asia as a child. She was asymptomatic with a normal physical examination. A repeat CT of her thorax demonstrated a round, circumscribed mass originating in the right lower lobe which had increased in size to 4.5 × 4.9 cm with compression of the right middle lobe and development of bronchiectasis (Figure 1). She underwent elective thoracotomy. An intraoperative frozen section was suggestive of a sclerosing hemangioma. She tolerated the procedure well, and was discharged on postoperative day six. Macroscopically, the pathologic specimen consisted of a lobectomy specimen which measured 13 × 12 × 5.5 cm weighing 202 gm with an oblong mass measuring 5.5 × 5.5 × 3 cm. The mass was approximately 1.5 cm from the vascular margin and 1.7 cm from the bronchial margin. Sectioning of the mass demonstrated a solid, well-circumscribed tan-red mass beneath the pleural surface. Microscopically, the mass demonstrated typical features of a sclerosing hemangioma. The predominant histology was one of sclerosis and solid growth, with areas of papillary growth and minimal hemorrhage. Immunohistochemical staining was positive for epithelial membrane antigen (EMA), thyroid transcription factor 1 (TTF-1), and focally weakly progesterone positive. Stains for S-100, estrogen, and HMB 45 were negative. Lymph nodes submitted were negative for metastasis (Figure 2).
DISCUSSIONS:Sclerosing hemangioma is a rare tumor of epithelial origin. It is most commonly seen in Asian females in their 40’s and is usually found incidentally. Symptoms arise from compression of surrounding lung and can include cough, dyspnea, chest pain, and hemoptysis. Radiographically, sclerosing hemagiomas appear as a well rounded, solitary mass. There is lower lobe predominance, with the right lung being more affected than the left. CT scans may demonstrate varying areas of attenuation and peripheral calcification, but enhancement is typical. The macroscopic appearance is a round mass of variable size. On cross section, it appears granular. Microscopically, there are four common patterns namely, cellular, papillary, hemorrhagic, and sclerosing, which present in varying degrees. Immunohistochemistry demonstrates an EMA and TTF-1 positive staining pattern. Atypical or mitotic cells are rarely seen.Sclerosing hemagiomas are usually benign, but multiple nodules and metastasis to local lymph nodes has been reported. The differential diagnosis includes carcinoid, hamartoma, angiosarcomas, bronchoalveolar carcinoma, clear cell tumors, and metastatic tumors with papillary components. Surgical resection is the therapy of choice. Limited surgical resection is acceptable if a definitive preoperative or intraoperative diagnosis is made, otherwise a lobectomy with lymph node dissection is preferred.
CONCLUSION:Sclerosing Hemangioma is a rare benign neoplasm of the lung with potential metastatic capability. Surgical resection with lymph node dissection and sampling is the preferred therapy. A wedge resection is appropriate if confirmatory intraoperative frozen section is definitive, otherwise lobectomy is preferred.
DISCLOSURE:Samir Makani, No Financial Disclosure Information; No Product/Research Disclosure Information