Ann Thorac Surg 2000;69:266-267
© 2000 The Society of Thoracic Surgeons
Case Reports
Pneumothorax necessitans presenting as a presternal pneumothoracocele
Sanjay P. Tripathi, MDa,
Malek G. Massad, MDa,
Vinod K. Mehta, MDa,
Enrico Benedetti, MDa,
Alexander S. Geha, MDa
a Division of Cardiothoracic Surgery, Department of Surgery, The University of Illinois at Chicago, Chicago, Illinois, USA
Address reprint requests to Dr Massad, Division of Cardiothoracic Surgery (M/C 958), The University of Illinois at Chicago, 840 South Wood St, CSB Suite 417, Chicago, IL 60612
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Abstract
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A 31-year-old woman who is an intravenous drug abuser developed sternoclavicular joint infection with mediastinal and subcutaneous tissue abscesses that communicated through an erosion in the manubrium caused by osteomyelitis. Air entrapment from a subsequent apical pneumothorax formed a localized anterior "pneumothoracocele." We referred to this condition as "pneumothorax necessitans," and we suggest including it in the differential diagnosis of anterior chest wall masses.
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Introduction
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Localized pneumothorax presenting as an enlarging anterior presternal air pocket has not been reported previously. In this communication, we describe this condition in a 31-year-old woman with a history of intravenous drug abuse who developed a defect in the manubrium due to osteomyelitis. An extension of a localized pneumothorax through that bony defect led to the subcutaneous air pocket that we referred to as "pneumothoracocele."
A 31-year-old woman with a history of intravenous drug abuse was admitted to a local hospital with a history of night sweats and a tender mass on the upper left parasternal chest wall of 3 weeks duration. On physical examination, her temperature was 37.5°C. She had a 10 x 8 cm firm and tender mass over the left sternoclavicular joint. Laboratory workup showed a white blood cell count (WBC) of 15,000/mm3 (85% neutrophils). A chest roentgenogram showed a soft tissue density in the anterior mediastinum. A computerized tomogram (CT scan) of the chest showed an 8 x 6 cm cystic mass in the anterior mediastinum in continuity with the soft tissue mass felt on examination with destructive changes in the manubrium and left sternoclavicular joint. The patient was started on intravenous antibiotics (pipracillin and gentamicin) and the anterior mediastinal abscess was drained percutaneously under CT guidance. Cultures of the mediastinal fluid grew Staphylococcus aureus. The patient experienced clinical improvement and left the hospital against advice; she was readmitted 2 weeks later with fever, shortness of breath, and a soft tender anterior chest wall mass. At that point her temperature was 39°C and her respiratory rate was 26 breaths/min. Her WBC was 24,000/mm3 with the differential count showing 19 bands. A chest roentgenogram showed bilateral pulmonary infiltrates and a small right pleural effusion. CT scan of the chest showed a loculated air collection in the left pleural apex and anterior mediastinum along with an air pocket in the subcutaneous tissue. An echocardiogram showed large vegetations on the tricuspid valve. With the diagnosis of pneumonia, endocarditis, and sepsis she was started on intravenous antibiotics. Sputum and blood cultures grew S aureus. After 3 weeks of intravenous antibiotics, she gradually recovered and left the hospital against advice.
Two weeks later she was admitted to our hospital with fever (38°C), tachypnea, and shortness of breath. On examination, a 15 x 10 cm soft and tender mass was present overlying the left sternoclavicular joint (Fig 1). A chest roentgenogram showed a radiolucent area over the left pleural apex. A CT scan of the chest showed a loculated left apical pneumothorax communicating with a large subcutaneous air collection anterior to the sternum with erosions within the manubrium suggestive of osteomyelitis (Fig 2). The mass grew substantially over the next 2 days after her admission. Due to the rapidly increasing size of the presternal air pocket and the suspicion of a communication with the left pleura and lung, the patient was taken to the operating room. With video-assisted thoracoscopy, left upper pleural adhesions were encountered and released. An apical bleb was identified extending through a defect in the manubrium into the anterior presternal air pocket. The apical bleb was stapled and divided with electrocautery thereby deflating the subcutaneous air collection. The defect in the manubrium became evident at that point. Punch biopsies of the edges of the manubrial defect were sent for cultures, all of which turned out negative. A left pleural apical chest tube was inserted. The postoperative course was uneventful and the patient was discharged home. An HIV test obtained during her latest hospitalization was negative.
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Fig 2. CT scan of the chest shows a loculated left apical pneumothorax communicating with a large subcutaneous air collection anterior to the sternum. Erosions within the manubrium are suggestive of osteomyelitis.
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Comment
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Inflammatory conditions involving the sternoclavicular joint occur in patients with rheumatoid and degenerative arthritis, ankylosing spondylitis, and septic arthritis [1]. Septic arthritis of the sternoclavicular joint is an infrequently seen infection, the diagnosis of which may be missed until the patient presents with a complication [2–4]. Pyarthrosis, and osteomyelitis with associated cutaneous abscesses, have been described previously [1]. The majority of sternoclavicular joint infections are caused by gram-positive organisms, particularly S aureus and group B Streptococcus. In uncomplicated cases, management consists of intravenous antibiotics and drainage of any potential abscess or collection.
The patient described in this report had a loculated apical pneumothorax that communicated with the subcutaneous tissue through a defect in the manubrium probably due to osteomyelitis. In this patient, sternoclavicular joint sepsis led to mediastinal and subcutaneous abscesses that communicated through an erosion in the manubrium and caused air entrapment from a subsequent pneumothorax. The well-formed abscess cavity prevented the entrapped air from dissecting along the subcutaneous tissue planes. We suggest referring to this condition as "pneumothorax necessitans" resulting in a "pneumothoracocele" and suggest including it in the differential diagnosis of anterior chest wall masses.
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References
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Asnis D.S., Dhaliwal G.S. Bilateral sternoclavicular joint septic arthritis presenting as cutaneous abscesses. Clin Infect Dis 1994;19:964-966.[Medline]
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Boll K.L., Jusik A.G. Sternal osteomyelitis in drug addicts. J Bone Joint Surg 1990;72:328-329.[Abstract/Free Full Text]
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Alexander P.W., Shin M.S. CT manifestations of sternoclavicular pyarthrosis in patients with intravenous drug abuse. J Comput Assist Tomogr 1990;14:104-106.[Medline]
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Chen W.S., Wan Y.L., Lui C.C., Lee T.Y., Wang K.C. Extrapleural abscess secondary to infection of the sternoclavicular joint. Report of two cases. J Bone Joint Surg Am 1993;75:1835-1839.[Free Full Text]
Accepted for publication May 23, 1999.
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Abstract
Introduction
