Volume 5, Case 13
Linda M. Rosen, MD
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
This is an 11-year old female who presents to the emergency department with a chief complaint of coughing up blood. She was spending the night at her grandmother's house when she was awakened at 5:00 am by a need to cough up mucous she felt was in her right chest. After repeated coughing she was able to bring up some mucous plugs and tasted blood. She then got up, ran to the bathroom and spit out approximately two tablespoons of bloody mucous. After this she felt fine but due to concern over the blood, she was brought to the emergency department. She had not felt ill upon going to bed that night and specifically denies fever, headache, rhinnorhea, cough. She did have some intermittent crampy abdominal pain for three days previous but had an increased appetite, attended school and had no vomiting or diarrhea. There is no history of ill contacts, unusual ingestions, trauma, bleeding or bruising.
Previous medical history reveals that she had a history of frequent bronchitis and has often been tired with poor appetite. Her mother wishes she would put on weight. She has never been hospitalized. No surgeries, no medications, no allergies.
Exam: VS: HR 110, RR 24, BP 110/70, Temp 37.0 (TM). She is a cooperative thin girl in no distress. HEENT exam is unremarkable. There are no nasal or oral lesions. Chest without increased work of breathing, nontender, clear to auscultation. Heart regular, grade II/VI soft systolic murmur along the left sternal border and a fixed split S2. Abdomen flat, soft, nontender without hepato/splenomegaly or masses. Skin well perfused without bruising or petechiae.
A CBC, PT/PTT and chest radiograph are ordered. The blood work is normal.
View chest radiograph [PA view]
[Lateral view]
This chest radiograph demonstrates slight cardiomegaly. There is prominent central pulmonary vascularity. The volume of the right lung is somewhat smaller than the left lung. There is a curvilinear density next to the right heart border. This can be seen on the PA view, but it is most prominent on the lateral view.
See the curvilinear density pointed out on the lateral view.
After seeing this chest radiograph you interview the patient and mother again. Mother is unaware that patient has had any abnormal heart murmur, she is not very athletic but has normal exercise tolerance without dyspnea, orthopnea, chest pain or cyanosis. She had a normal neonatal course. Family history is unremarkable.
A echocardiogram and CT scan of the chest are ordered.
View chest CT.
CT1: This cut of the upper chest shows the right lung to be smaller than the left. Also note the different vascular pattern on each side.
CT2: This cut shows that the right lung is bi-lobar as demonstrated by the bifurcation of the right mainstem bronchus (arrow), a pattern usually seen only in the left lung.
Review of this CT of the chest demonstrates that this patient has a generally hypoplastic right lung with abnormal systemic blood supply to the right lower lung directly from the aorta. There is also an anomalous pulmonary vein from below the diaphragm draining into the inferior vena cava. These findings are consistent with the "Scimitar Syndrome". The echocardiogram demonstrates an atrial septal defect. The patient undergoes surgery for correction of her atrial septal defect and redirection of the abnormal pulmonary vein. She does well clinically.
Two years after surgery, she presents with a history of frequent coughing and vague right sided chest pain. A chest radiograph is obtained.
View chest radiograph.
Her chest radiograph now shows a normal heart size. The differences in size and vascularity of the right and left lung are more pronounced.
Discussion
This patient's findings are consistent with several of the features of a syndrome variously described as Scimitar Syndrome, Halasz's Syndrome and Venolobar Syndrome, the primary feature of which is an abnormal drainage of a right pulmonary vein into the vena cava. This abnormal drainage was first described by a British surgeon, Cooper, in 1836. The abnormal vessel he described can often be seen on plain chest radiograph as a curvilinear density along the right heart border. Because of this appearance, the anomaly was subsequently named the "scimitar syndrome" by Neill, et al, in 1960. Although the abnormal venous drainage is the most recognized anomaly, which has given rise to the popular name, there is most often a group of additional associated anomalies of the right lung which may include:
1. Partial agenesis or hypoplasia of the right lung with bronchial isomerism, and diverticulum or hypoplasia of the right bronchial system.
2. Hypoplasia or agenesis of the right pulmonary artery.
3. Dextrocardia.
4. Congenital cardiac malformations.
5. Abnormal systemic blood supply to at least part of the right lung, most frequently the posterior basal segment of the lower lobe.
6. Abnormal venous drainage. A vessel emptying from below into the inferior vena cava is most common and forms the "scimitar" seen on chest radiographs but other forms of anomalous pulmonary venous drainage, sometimes with obstruction, are found.
The etiology of this association of malformations is unknown but is felt to be due to abnormal development of the entire right lung bud early in embryogenesis. The reason for vulnerability of the right lung is not understood, but the association of malformations has only been reported to occur in the left lung with extreme rarity. The scimitar syndrome is known to be more common in females. It is occassionally familial. The clinical presentation assumes three basic forms.
Some patients, approximately one fourth, are symptomatic in the newborn period presenting with respiratory insufficiency and/or cardiac failure. The most common underlying physiologic disturbance has been demonstrated to be pulmonary hypertension produced by the right lung anomalies. The mechanism for pulmonary hypertension is most often a large left to right shunt via the systemic arterial supply to the right lung. Partially obstructed pulmonary venous return may contribute to pulmonary hypertension. Additional symptomatology in the newborn period may be caused by associated congential heart defects.
Approximately 25% of patients with the scimitar syndrome have associated cardiac anomalies, most commonly atrial septal defect, but also intraventricular defects, coarctation of the aorta, tetralogy of Fallot, pulmonic stenosis and persistent left superior vena cava.
Surgery is indicated for patients symptomatic during the newborn period. Its success is dependant on the nature and severity of the underlying abnormalities. The general aim of surgery is to reduce any systemic shunting, and if necessary, to redirect pulmonary venous return. Complete studies delineating the vascular and ventilation patterns must be completed in order to plan appropriate surgery.
The second type of presentation is associated with recurrent pulmonary infections during young adulthood. These infections are usually of the right lower lobe which is the one most likely to have an abnormal arterial supply and venous drainage. These patients may require partial lobectomy or occasionally right pneumonectomy to prevent recurrent infections. Post-operative prognosis is generally good.
The third presentation, which is farily common, is that the syndrome is found incidentally in a patient who has a chest radiograph as in the case presented. These patients have minimal if any symptoms and may be managed conservatively. Although our patient was felt to be somewhat thin and not terribly athletic, she had only one episode of hemoptysis which may be attributable to her anomalies. If our patient did not have an atrial septal defect, surgery would probably not have been done.
There is some overlap between reported cases of scimitar syndrome and those classified as pulmonary sequestration (refer to the next case, Case 14 of Volume 5). As mentioned, the term "Venolobar" syndrome has also been used to encompass the vascular and general lung anomlies grouped together. In a recent review by Woodring et al, in the journal, Radiographics, the authors use the term "congenital pulmonary venolobar syndrome" (CPVS). They state "Major components of CPVS include hypogenetic (ie., hypoplastic) lung, partial anomalous pulmonary venous return (this and the former are two of the most constantly occurring components), absence of a pulmonary artery, pulmonary sequestration, systemic arterialization of the lung, absence of the inferior vena cava, and accessory diaphragm. Minor components of CPVS include tracheal trifurcation, eventration and partial absence of the diaphragm, phrenic cyst, horseshoe lung, esophageal and gastric lung, anomalous superior vena cava, and absence of the pericardium."
Thus the term "scimitar syndrome" may be misleading. Although the anomalous vein of the "scimitar" is one of the most consistent findings in this group of anomalies, it may be absent when the anomalous drainage takes another anatomic form. The term "Congenital Pulmonary Venolobar Syndrome (CPVS)" may be a more rational umbrella for this grouping of anomalies of the right hemithorax, but not nearly as catchy as "Scimitar Syndrome". Findings of any of the aforementioned anomalies should prompt a complete evaluation for the others. There have been rare reports of abnormalities of the left lung which mimic the scimitar syndrome.
References