Diagnostic Radiology
The Air Meniscus Sign in Sclerosing Hemangioma of the Lung 1 Yong Whee Bahk, M.D., Kyung Sub Shinn, M.D., and Byung Suk Choi, M.D.2 The air meniscus sign occurs in a number of lung conditions, including infection, benign and malignant tumors, and hematoma. Sclerosing hemangioma does not appear to have been implicated previously in this connection. Two such cases are described. Possible mechanisms of air meniscus formation and its diagnostic value in sclerosing hemangioma are discussed. INDEX TERMS: Angioma. Lung neoplasms, diagnosis (Lung, other benign tumor, 6[0].319; Lung, other fundamental observation, 6 [0] .919) Radiology 128:27-29, July 1978
HE AIR meniscus sign, also known as air chamber, air cap, air crescent, and periparasitic emphysema, is characterized by a crescent-shaped radiolucent shadow at the periphery of a mass lesion of the lung. Originally described by Zehbe (14) in 1916 in a patient with pulmonary echinococcal cyst, the sign was once regarded as pathognomonic of hydatid disease (4,6); however, since then a number of pulmonary conditions have been reported to produce the same finding (11), most recently traumatic hematoma (2). We wish to describe what we believe to be the first 2 cases of sclerosing hemangioma of the lung associated with the air meniscus sign.
T
the tumor. The histological diagnosis was sclerosing hemangioma of the lung in the late stage. The patient made an uneventful recovery and was discharged on October 1. He was in good condition without evidence of recurrence 22 months later. CASE II: A 36-year-old woman was admitted to Severance Hospital on March 29, 1977 following the discovery of a solitary circumscribed lesion in the right middle lung on a routine chest radiograph one month earlier. The patient denied coughing, sputum, chest pain, or other symptoms. Tuberculosis was diagnosed and she was treated with isoniazid, streptomycin, and Myambutol. On physical examination she looked healthy and in no distress. Chest auscultation and percussion were unremarkable and vital signs were within normal limits. A complete blood-cell count, pulmonary function test, and other routine laboratory studies were all within the normal range. Repeated concentration and smear tests of sputum for acid-fast bacilli were negative. Anterior and right lateral views of the chest revealed a rounded mass 3.8 cm in diameter involving the superior segment of the right lower lobe. No other pulmonary lesion or hilar enlargement was noted. The mass was well defined except for the lower portion, where a thin, radiolucent meniscus was noted (Fig. 2, A). Tomograms confirmed that this was a typical air meniscus surrounding the lower hemisphere of the mass (Fig. 2, B). No calcifications were seen within the mass. Fungus ball of aspergillosis, a tuberculous cavity with blood clot, and adenoma were suggested. The patient underwent thoracotomy on the fourth hospital day. On opening the right thoracic cage, the pleura was free of effusion, adhesion, or discoloration. The tumor was palpable in the superior segment of the right lower lobe. It was removed after its benign nature was confirmed by a frozen-section study. Pathologically, the tumor was ovoid and well demarcated, with a capsule within the parenchyma of the superior segment of the right lower lobe. There was no connection to any of the dissected bronchi. On sectioning, some blood poured forth. The cut surface was grayish in color and sponge-like. A semicircular rim of free space 2 mm wide was noted between the periphery of the tumor and the capsule, which was composed of compressed lung tissue. The histological diagnosis was sclerosing hemangioma in the cellular phase with hemorrhage. The patient made an uneventful recovery and was discharged on the fourteenth hospital day.
CASE REPORTS CASE I: A 55-year-old man was admitted to St. Mary's Hospital on September 1, 1975 following the discovery of a tumor in the right lower lung on a routine radiographic examination. The patient was in good health, with no complaints except for coughing which he attributed to smoking cigarettes for 35 years. Chest auscultation and percussion were unremarkable and vital signs were within normal limits. Hematologic tests and other routine laboratory studies were all within the normal range. Sputum studies were negative for acid-fast bacilli, other pathogenic organisms, and malignant cells. Chest radiographs revealed a sharply demarcated solitary mass 4.5 cm in diameter involving the anterior basal segment of the right lower lobe. There were no other lung lesions or hilar enlargement. Tomograms showed a small air meniscus shadow in the upper medial aspect of the mass (Fig. 1, A) with slight notching of the lesion contour. No calcifications were seen within the mass. Bronchograms showed dislocation of the regional bronchi but no intrinsic bronchial abnormalities or connection with the mass. A benign tumor or a granuloma was considered. The patient underwent thoracotomy on the fourth hospital day. On opening the right thoracic cage, the pleural cavity was intact. The mass was easily palpated in the anterior basal segment of the right lower lobe. It was removed after a frozen-section study confirmed that it was benign. The tumor was rubbery hard, measuring 3.8 cm in diameter, and was sharply demarcated from neighboring lung tissues. The cut surface was yellowish white and shiny. There was a 1.5 X 7-mm slit-like defect in the upper medial aspect (Fig. 1, B). Microscopically, the defect represented many dilated, ruptured, and coalesced distal air spaces within
DISCUSSION
It is now clear that the air meniscus sign, once consid-
1 From the Departments of Radiology of St. Mary's Hospital, Catholic Medical College (Y.W.B., K.S.S.) and Severance Hospital, Yonsei University Medical School (B.S.C.), Seoul, Korea. Accepted for publication in February 1978. 2 Deceased.
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YONG WHEE BAHK AND OTHERS
July 1978
Fig. 1 A. Tomogram of the right lower lobe reveals a 4.5-cm sharply demarcated solitary tumor. A small slit-like air meniscus (arrowheads) is visible in the upper medial aspect. B. The cut surface of the tumor exhibits a slit-like defect which matches the meniscus shadow demonstrated in Figure 1, A. Histologically, the defect represented dilated, ruptured, and coalesced distal air spaces.
ered pathognomonic of pulmonary echinococcal cyst, can occur in a number of lung diseases. The most common cause is probably the intracavitary fungus ball of Aspergillus fumigatus (7, 8, 13); lung abscess (3), tuberculous cavity with Rasmussen aneurysm formation (12), bronchial adenoma (7), and bronchogenic carcinoma (5) are also occasionally seen. The concept of aging of pulmonary hemangiomas was proposed by Mori (10). Based on the literature and his own experience, he emphasized the histological evolution of sclerosing hemangioma from hemangioblastoma. In this context, it is interesting to note that the age of our patients was 55 and 36 years, respectively, suggesting that the tumor in the former patient would have started much earlier chronologically than in the latter case and had reached its late evolutional stage by the time we saw it. Two possible mechanisms may operate in the production of an air meniscus in sclerosing hemangioma. Probably the more important of these is proliferation and hyalinization of undifferentiated alveolar mesenchymal cells, which may wrap around the bronchus and lead to distension of the distal air spaces (1, 9, 11), with the extent and shape determined by the physical characteristics of the tumor tissues: thus the meniscus may be small and slit-like in a tumor with advanced hyalinization, as in CASE I, or have a prominent rim in a relatively cellular tumor, as in CASE II. The other possibility is that the air meniscus is the
result of disparate rates of contraction of the capsule and tumor, particularly when the tumor is highly cellular and hemorrhagic. Recently, Bard and Hassani (2) described the air meniscus sign in a patient with traumatic hematoma of the lung and gave this explanation for the phenomenon. We further speculate that a meniscus formed in this manner may become inflated through a bronchial communication, which may have occurred in our CASE II. Sclerosing hemangioma presents as a sharply defined solitary mass with a predilection for the right lower lobe in middle-aged women (1,9, 11). The patient may complain of hemoptysis and coughing or be entirely asymptomatic. Therefore, radiographic demonstration of an air meniscus in a tumor having these clinical features should be highly suggestive of sclerosing hemangioma. Department of Radiology St. Mary's Hospital Catholic Medical College Seoul 100 Korea
REFERENCES 1. Arean VM, Wheat MW Jr: Sclerosing hemangiomas of the lung. A case report and review of the literature. Am Rev Resp Dis 85:261-271, Feb 1962 2. Bard R, Hassani N: Crescent sign in pulmonary hematoma. Respiration 32:247-251, 1975
Vol. 128
THE AIR MENISCUS SIGN IN SCLEROSING HEMANGIOMA OF THE LUNG
29
Diagnostic Radiology
Fig. 2. A. Anterior chest radiograph shows a 3.8-cm rounded mass in the right middle lung. Close observation reveals a thin air meniscus involving the lower hemisphere. B. Tomogram shows a sharply defined semicircular air meniscus surrounding the lower half of the mass.
3. Bobrowitz 10: Round densities within cavities. Lung lesions simulating the pathognomonic roentgen sign of echinococcus cyst. Am Rev Tuberc 50:305-312, Oct 1944 4. Caeiro JA, Goyena JR: Quiste hidatkilco del lobule superior del pulrnon Izquierdo. Bol Trab Soc Cir Buenos Aires 17:144-153, 3 May 1933 [Quoted by Evans (6)] 5. Cubillo-Herguera E, McAlister WH: The pulmonary meniscus sign in a case of bronchogenic carcinoma. Radiology 92: 1299-1300, May 1969 6. Evans WA Jr: Echinococcus cyst of the lung. Radiology 40: 362-366, Apr 1943 7. Felson B: Causes of meniscus sign (Table 8-3). [In] Chest Roentgenology. Philadelphia, Saunders, 1973, p 327 8. Levin EJ: Pulmonary intracavitary fungus ball. Radiology 66:9-15, Jan 1956
9. Liebow AA, Hubbell OS: Sclerosing hemangioma (histiocytoma, xanthoma) of the lung. Cancer 9:53-75, Jan-Feb 1956 10. Mori S: Sclerosing hemangioma of the lung. Dis Chest 54: 381-384, Oct 1968 11. Spencer H: Sclerosing angioma of the lung (sclerosing granuloma). [In] Pathologyof the Lung. Oxford, Pergamon, 2d Ed, 1968, pp 933-937 12. Stivelman BP, Malev M: Rasmussen aneurysm: its roentgen appearance. Report of a case with necropsy. JAMA 110: 1829-1831, 28 May 1938 13. Weens HS, Thompson EA: The pulmonary air meniscus. Radiology 54:700-705, May 1950 14. Zehbe: Uber Lungen- und Pleura-Echinokokkus. Fortschr Geb Roentgenstr Nuklearmed 24:63-65, 1916-1917 [Quoted by Evans (6)]
The Air Meniscus Sign in Sclerosing Hemangioma of the Lung 1 Yong Whee Bahk, M.D., Kyung Sub Shinn, M.D., and Byung Suk Choi, M.D.2 The air meniscus sign occurs in a number of lung conditions, including infection, benign and malignant tumors, and hematoma. Sclerosing hemangioma does not appear to have been implicated previously in this connection. Two such cases are described. Possible mechanisms of air meniscus formation and its diagnostic value in sclerosing hemangioma are discussed. INDEX TERMS: Angioma. Lung neoplasms, diagnosis (Lung, other benign tumor, 6[0].319; Lung, other fundamental observation, 6 [0] .919) Radiology 128:27-29, July 1978
HE AIR meniscus sign, also known as air chamber, air cap, air crescent, and periparasitic emphysema, is characterized by a crescent-shaped radiolucent shadow at the periphery of a mass lesion of the lung. Originally described by Zehbe (14) in 1916 in a patient with pulmonary echinococcal cyst, the sign was once regarded as pathognomonic of hydatid disease (4,6); however, since then a number of pulmonary conditions have been reported to produce the same finding (11), most recently traumatic hematoma (2). We wish to describe what we believe to be the first 2 cases of sclerosing hemangioma of the lung associated with the air meniscus sign.
T
the tumor. The histological diagnosis was sclerosing hemangioma of the lung in the late stage. The patient made an uneventful recovery and was discharged on October 1. He was in good condition without evidence of recurrence 22 months later. CASE II: A 36-year-old woman was admitted to Severance Hospital on March 29, 1977 following the discovery of a solitary circumscribed lesion in the right middle lung on a routine chest radiograph one month earlier. The patient denied coughing, sputum, chest pain, or other symptoms. Tuberculosis was diagnosed and she was treated with isoniazid, streptomycin, and Myambutol. On physical examination she looked healthy and in no distress. Chest auscultation and percussion were unremarkable and vital signs were within normal limits. A complete blood-cell count, pulmonary function test, and other routine laboratory studies were all within the normal range. Repeated concentration and smear tests of sputum for acid-fast bacilli were negative. Anterior and right lateral views of the chest revealed a rounded mass 3.8 cm in diameter involving the superior segment of the right lower lobe. No other pulmonary lesion or hilar enlargement was noted. The mass was well defined except for the lower portion, where a thin, radiolucent meniscus was noted (Fig. 2, A). Tomograms confirmed that this was a typical air meniscus surrounding the lower hemisphere of the mass (Fig. 2, B). No calcifications were seen within the mass. Fungus ball of aspergillosis, a tuberculous cavity with blood clot, and adenoma were suggested. The patient underwent thoracotomy on the fourth hospital day. On opening the right thoracic cage, the pleura was free of effusion, adhesion, or discoloration. The tumor was palpable in the superior segment of the right lower lobe. It was removed after its benign nature was confirmed by a frozen-section study. Pathologically, the tumor was ovoid and well demarcated, with a capsule within the parenchyma of the superior segment of the right lower lobe. There was no connection to any of the dissected bronchi. On sectioning, some blood poured forth. The cut surface was grayish in color and sponge-like. A semicircular rim of free space 2 mm wide was noted between the periphery of the tumor and the capsule, which was composed of compressed lung tissue. The histological diagnosis was sclerosing hemangioma in the cellular phase with hemorrhage. The patient made an uneventful recovery and was discharged on the fourteenth hospital day.
CASE REPORTS CASE I: A 55-year-old man was admitted to St. Mary's Hospital on September 1, 1975 following the discovery of a tumor in the right lower lung on a routine radiographic examination. The patient was in good health, with no complaints except for coughing which he attributed to smoking cigarettes for 35 years. Chest auscultation and percussion were unremarkable and vital signs were within normal limits. Hematologic tests and other routine laboratory studies were all within the normal range. Sputum studies were negative for acid-fast bacilli, other pathogenic organisms, and malignant cells. Chest radiographs revealed a sharply demarcated solitary mass 4.5 cm in diameter involving the anterior basal segment of the right lower lobe. There were no other lung lesions or hilar enlargement. Tomograms showed a small air meniscus shadow in the upper medial aspect of the mass (Fig. 1, A) with slight notching of the lesion contour. No calcifications were seen within the mass. Bronchograms showed dislocation of the regional bronchi but no intrinsic bronchial abnormalities or connection with the mass. A benign tumor or a granuloma was considered. The patient underwent thoracotomy on the fourth hospital day. On opening the right thoracic cage, the pleural cavity was intact. The mass was easily palpated in the anterior basal segment of the right lower lobe. It was removed after a frozen-section study confirmed that it was benign. The tumor was rubbery hard, measuring 3.8 cm in diameter, and was sharply demarcated from neighboring lung tissues. The cut surface was yellowish white and shiny. There was a 1.5 X 7-mm slit-like defect in the upper medial aspect (Fig. 1, B). Microscopically, the defect represented many dilated, ruptured, and coalesced distal air spaces within
DISCUSSION
It is now clear that the air meniscus sign, once consid-
1 From the Departments of Radiology of St. Mary's Hospital, Catholic Medical College (Y.W.B., K.S.S.) and Severance Hospital, Yonsei University Medical School (B.S.C.), Seoul, Korea. Accepted for publication in February 1978. 2 Deceased.
27
28
YONG WHEE BAHK AND OTHERS
July 1978
Fig. 1 A. Tomogram of the right lower lobe reveals a 4.5-cm sharply demarcated solitary tumor. A small slit-like air meniscus (arrowheads) is visible in the upper medial aspect. B. The cut surface of the tumor exhibits a slit-like defect which matches the meniscus shadow demonstrated in Figure 1, A. Histologically, the defect represented dilated, ruptured, and coalesced distal air spaces.
ered pathognomonic of pulmonary echinococcal cyst, can occur in a number of lung diseases. The most common cause is probably the intracavitary fungus ball of Aspergillus fumigatus (7, 8, 13); lung abscess (3), tuberculous cavity with Rasmussen aneurysm formation (12), bronchial adenoma (7), and bronchogenic carcinoma (5) are also occasionally seen. The concept of aging of pulmonary hemangiomas was proposed by Mori (10). Based on the literature and his own experience, he emphasized the histological evolution of sclerosing hemangioma from hemangioblastoma. In this context, it is interesting to note that the age of our patients was 55 and 36 years, respectively, suggesting that the tumor in the former patient would have started much earlier chronologically than in the latter case and had reached its late evolutional stage by the time we saw it. Two possible mechanisms may operate in the production of an air meniscus in sclerosing hemangioma. Probably the more important of these is proliferation and hyalinization of undifferentiated alveolar mesenchymal cells, which may wrap around the bronchus and lead to distension of the distal air spaces (1, 9, 11), with the extent and shape determined by the physical characteristics of the tumor tissues: thus the meniscus may be small and slit-like in a tumor with advanced hyalinization, as in CASE I, or have a prominent rim in a relatively cellular tumor, as in CASE II. The other possibility is that the air meniscus is the
result of disparate rates of contraction of the capsule and tumor, particularly when the tumor is highly cellular and hemorrhagic. Recently, Bard and Hassani (2) described the air meniscus sign in a patient with traumatic hematoma of the lung and gave this explanation for the phenomenon. We further speculate that a meniscus formed in this manner may become inflated through a bronchial communication, which may have occurred in our CASE II. Sclerosing hemangioma presents as a sharply defined solitary mass with a predilection for the right lower lobe in middle-aged women (1,9, 11). The patient may complain of hemoptysis and coughing or be entirely asymptomatic. Therefore, radiographic demonstration of an air meniscus in a tumor having these clinical features should be highly suggestive of sclerosing hemangioma. Department of Radiology St. Mary's Hospital Catholic Medical College Seoul 100 Korea
REFERENCES 1. Arean VM, Wheat MW Jr: Sclerosing hemangiomas of the lung. A case report and review of the literature. Am Rev Resp Dis 85:261-271, Feb 1962 2. Bard R, Hassani N: Crescent sign in pulmonary hematoma. Respiration 32:247-251, 1975
Vol. 128
THE AIR MENISCUS SIGN IN SCLEROSING HEMANGIOMA OF THE LUNG
29
Diagnostic Radiology
Fig. 2. A. Anterior chest radiograph shows a 3.8-cm rounded mass in the right middle lung. Close observation reveals a thin air meniscus involving the lower hemisphere. B. Tomogram shows a sharply defined semicircular air meniscus surrounding the lower half of the mass.
3. Bobrowitz 10: Round densities within cavities. Lung lesions simulating the pathognomonic roentgen sign of echinococcus cyst. Am Rev Tuberc 50:305-312, Oct 1944 4. Caeiro JA, Goyena JR: Quiste hidatkilco del lobule superior del pulrnon Izquierdo. Bol Trab Soc Cir Buenos Aires 17:144-153, 3 May 1933 [Quoted by Evans (6)] 5. Cubillo-Herguera E, McAlister WH: The pulmonary meniscus sign in a case of bronchogenic carcinoma. Radiology 92: 1299-1300, May 1969 6. Evans WA Jr: Echinococcus cyst of the lung. Radiology 40: 362-366, Apr 1943 7. Felson B: Causes of meniscus sign (Table 8-3). [In] Chest Roentgenology. Philadelphia, Saunders, 1973, p 327 8. Levin EJ: Pulmonary intracavitary fungus ball. Radiology 66:9-15, Jan 1956
9. Liebow AA, Hubbell OS: Sclerosing hemangioma (histiocytoma, xanthoma) of the lung. Cancer 9:53-75, Jan-Feb 1956 10. Mori S: Sclerosing hemangioma of the lung. Dis Chest 54: 381-384, Oct 1968 11. Spencer H: Sclerosing angioma of the lung (sclerosing granuloma). [In] Pathologyof the Lung. Oxford, Pergamon, 2d Ed, 1968, pp 933-937 12. Stivelman BP, Malev M: Rasmussen aneurysm: its roentgen appearance. Report of a case with necropsy. JAMA 110: 1829-1831, 28 May 1938 13. Weens HS, Thompson EA: The pulmonary air meniscus. Radiology 54:700-705, May 1950 14. Zehbe: Uber Lungen- und Pleura-Echinokokkus. Fortschr Geb Roentgenstr Nuklearmed 24:63-65, 1916-1917 [Quoted by Evans (6)]
