Visual diagnosis: an adolescent female who has persistent cough.

Abstract

A previously healthy 17-year-old girl complains of a “dry and intermittent” cough for the past 1.5 months. The cough worsens when she is recumbent and does not respond to over-the-counter cough medications. The cough is not associated with fever, chills, nausea, vomiting, night sweats, or weight loss. She reports several episodes of posttussive chest pain. Recently prescribed treatments of albuterol and fexofenadine do not alleviate her symptoms, despite her clinical diagnoses of exercise-induced bronchospasm and allergic rhinitis. She is an accomplished basketball player; her cough does not diminish her athletic performance.The patient’s past medical history is remarkable for a cardiac murmur noted at birth that resolved by 2 years of age and for three episodes of pneumonia by 6 months of age. She has no drug or environmental allergies, her immunizations are up-to-date, and her growth and development are normal. She denies drug, alcohol, or tobacco use. Further review of a psychosocial history reveals minimal adolescent risk characteristics.For the past 6 years, she has lived in the southwest United States and spent the prior summer in northern California. She denies exposure to others who had chronic cough, tuberculosis, or lung diseases. She admits to watching bats on one occasion during vacation in the past year.On physical examination, the patient appears healthy and is in no apparent distress. Vital signs are: temperature, 36.8°C (98.2°F); respiratory rate, 22 breaths/min; pulse, 88 beats/min; blood pressure, 117/73 mm Hg; and pulse oximetry, 100% hemoglobin-oxygen saturation while breathing room air. The patient’s respirations are unlabored, and she has adequate air movement. Auscultation of the chest reveals decreased breath sounds over the left base and fine, end-inspiratory crackles within the midposterior left chest. There is no appreciable egophony. The remainder of the physical findings are normal.A complete blood count reveals a white blood cell count of 9 × 103/mcL (9 × 109/L), with 74% neutrophils and 20% lymphocytes; hemoglobin of 13 g/dL (130 g/L); hematocrit of 40% (0.40); and platelet count of 263 × 103/mcL (263 × 109/L). Results of serum chemistries, coagulation profiles, and urinalysis are normal. A pregnancy test is negative. A chest radiograph (Fig. 1) demonstrates opacification of the left lower lobe with air-fluid levels. High-resolution computed tomography (CT) of the chest demonstrates an abscess in the left lower lung as well as cystic lesions extending superiorly to the level of the carina (Fig. 2). Blood cultures are obtained, a Mantoux skin test is placed, and treatment with intravenous cefuroxime, azithromycin, and clindamycin is initiated.The extent of lung disease prompts further diagnostic examination. Flexible fiberoptic bronchoscopy surprisingly reveals moderate left lower lobe bronchial erythema and minimal acute inflammation of the posterior segment bronchus. There is no evidence of confluent necrosis or granuloma formation. Bronchial washings show many leukocytes but no bacteria. Acid-fast stain is negative for organisms. Cultures of bronchoalveolar lavage fluid reveal no growth of fungi or bacteria.Blood cultures grow no organisms after 5 days of incubation. A serum titer for Mycoplasma immunoglobulin G (IgG) is negative. Legionella IgG and urine antigen are not detected. Serum titers for Histoplasma, Coccidioides, and Blastomyces antibodies are negative. Further imaging reveals the underlying diagnosis.Ultrasonography of the chest (Fig. 3) demonstrates two vessels branching directly from the aorta. These thoracic vessels appear to supply a mass in the left lower lung. The mass is multicystic and has multiple echogenic solid components. Pediatric surgeons perform a lobectomy and resect the mass. The final pathologic diagnosis is pulmonary sequestration, with adjacent cysts believed to be due to chronic lung disease.Chronic cough, defined as cough persisting longer than 3 weeks, affects up to 25% of school children and is a frequent reason for outpatient pediatric examination. Chronic or recurrent cough has an extensive differential diagnosis, but the most common causes are viral upper respiratory tract infection and reactions to atmospheric pollutants. Clinical evaluation is necessary to tailor a progressive, stepwise treatment for a specific cause.Patients suffering from chronic cough fall into two groups: those who may benefit from empiric treatment of symptoms and those who merit further evaluation prior to treatment. A thorough history of the cough and any associated symptoms along with a physical examination form the basis of the initial evaluation. Use of over-the-counter medications and their effects should be documented, as well as any family history of atopy, reactive airway disease, ciliary dysmotility syndromes, and cystic fibrosis. Travel history may reveal significant exposures to fungi, mycobacteria, parasites, or bacteria. Investigation of social history, personal habits, and risky behaviors (especially in the adolescent population) may indicate exposure to cigarette smoke, use of inhalant drugs or volatile fumes, and alcohol consumption. A chest radiograph is indicated if empiric therapy does not improve the chronic cough.In this patient’s case, the initial screening history, lack of response to medications, and results of physical and initial laboratory examinations suggested an underlying infectious etiology of the cough. Further evaluation was necessary to establish a firm diagnosis and to direct treatment. The finding on chest radiography of consolidation and air-fluid-filled cavitations in the left lower lung was surprising but not wholly unexpected, given the insidious clinical course and complaints of chronic cough and intermittent chest pain.A lung abscess is a suppurative process that leads to destruction of pulmonary parenchyma and formation of cavitations. In children, lung abscesses result from aspiration of significant amounts of infected material that overwhelm host defense mechanisms, from hematogenous seeding, or from accumulation of suppurative material behind an inhaled foreign body. Pulmonary abscess following aspiration develops most frequently in the posterior segment of the right upper lobe, but it also may appear in the apical segments of the lower lobes. Aspiration pneumonia and lung abscess are seen commonly in patients who lack oropharyngeal coordination or have significant periodontal disease. However, otherwise healthy individuals also may aspirate a significant inoculum of microorganisms during trauma or an altered state of consciousness due to such conditions as diabetic ketoacidosis or intoxication with drugs or alcohol. Seventy-five percent of aspiration-related pulmonary abscesses contain anaerobic organisms. Rarer causes include infections with Nocardia, Actinomyces, mycobacteria, Histoplasma capsulatum, or Coccidioides immitis.Although chest radiography may demonstrate a pulmonary abscess, further evaluation by chest CT, bacterial and fungal serologic testing, and fiberoptic bronchoscopy with endobronchial brushing and bronchoalveolar lavage may be necessary to determine appropriate therapy. Identification of an organism from transtracheal aspirate, blood, or pleural fluid guides the antibiotic choice. A Gram stain of sputum also may direct therapy in the context of known or suspected aspiration.In this case, fiberoptic bronchoscopy did not reveal physical evidence of a pulmonary abscess. High-resolution chest CT findings were consistent with the diagnosis of pulmonary abscess but also suggested the possibility of congenital lung anomaly. Closer review of the CT scan revealed an arterial feeder vessel leading to the abscess (Fig. 4), which already had been demonstrated by chest ultrasonography.Developmental anomalies of the lungs are rare. A retrospective review of admissions at three major pediatric tertiary care referral centers over a 20-year period shows that almost three congenital pulmonary malformations are diagnosed each year. Congenital malformations of the lung include bronchogenic cysts, pulmonary cysts, congenital cystic adenomatoid malformations (CCAMs), pulmonary sequestration, and lobar emphysema. Pulmonary sequestration and CCAMs account for approximately 30% of these malformations.A pulmonary sequestration is a nonfunctional mass of pulmonary tissue that does not communicate with the conducting airways and has its own systemic blood supply. Sequestered pulmonary tissue may be intra- or extralobar, a distinction made by the presence or absence of an independent investing visceral pleura. Tissue samples from pulmonary sequestrations reflect a full complement of normal pulmonary components. CCAMs, in contrast, communicate with the main tracheobronchial tree, derive vascular supply from the bronchial circulation, and have a proliferation of terminal bronchioles with suppression of alveolar growth and development. On histologic examination, CCAMs show a predominance of elastic tissue and are devoid of cartilage.Although the exact pathogenesis is controversial, both pulmonary sequestrations and CCAMs apparently result from aberrant embryologic development at specific points during tracheobronchial and alveolar maturation. Pulmonary sequestration results from an “insult” that affects abnormal development of the pulmonary bud and accompanying pulmonary blood vessels. Whether caused by local trauma, ischemia, or a pre-existing genetic mutation, development of the pulmonary bud is abnormal, and vessels from the arterial foregut plexus persist. Variations in the timing and severity of the insult may alter the ultimate phenotype.Most pulmonary sequestrations are discovered incidentally on a chest radiograph performed during childhood or adolescence. Pulmonary sequestration appears more frequently in males than in females—approximately 1.5:1 for intralobar and 3:1 for extralobar sequestration. If clinical symptoms exist, they are usually nonspecific, although the intralobar type of pulmonary sequestration may lead to recurrent pneumonia. Pulmonary sequestration often is associated with other congenital malformations, such as congenital diaphragmatic hernia. A collection of cystic lesions, focal consolidations, or air-fluid levels may appear on chest radiography. Fluid-filled cysts may appear opaque radiologically and may be mistaken for consolidations. The resulting determination of pneumonia may delay ascertainment of the true diagnosis. High-resolution CT with contrast allows characterization of the extent of the lesion and its vascular supply. Color Doppler ultrasonography of the chest currently is considered the most accurate modality with which to define the systemic feeder vessels (Fig. 3), although some authors stress the value of angiography.Surgical resection and lobectomy of the pulmonary sequestration is curative, has a low morbidity rate, and is necessary to prevent further disease due to recurrent infection.Persistent tachypnea and wheezing are other signs that may indicate underlying congenital disease. This article reminds us to pursue further evaluation of the cough, wheeze, or pneumonia that recurs frequently or does not improve with therapy.Joseph A. Zenel, MDEditor, Visual DiagnosisA circumscribed collection of pus appearing in an acute or chronic localized infection and associated with tissue destruction.Cystic congenital lung lesion consisting of a single lobe of lung that communicates with the main tracheobronchial tree. It derives its vascular supply from the bronchial circulation and has a proliferation of terminal bronchioles with suppression of alveolar growth and development.High-pitched, discrete, discontinuous crackling sounds heard during the end of inspiration that are believed to represent the sudden explosive opening of previously closed airways. Their presence indicates underlying pulmonary parenchymal disease.Pulmonary sequestration that has an independent investing visceral pleura.Pulmonary sequestration that shares a common investing visceral pleura with adjacent normal lung tissue.Nonfunctional mass of pulmonary tissue that does not communicate with the conducting airways and has its own systemic blood supply.