Introduction

Postprimary pulmonary tuberculosis (TB) is generallyconsidered to be a disease of adults, occasionally occur-ring in adolescents [1, 2, 3]. The radiographic appearanceof postprimary pulmonaryTB in adults has been reviewedin the literature [2, 3, 4, 5], as has the appearance of pri-marypulmonaryTB inchildren [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11].The objective of this paper is to review the radiographicappearance of pediatric postprimary pulmonary TB.

Materials and methods

Cases were located from the teaching files of a pediatric radiologist,a search of the Central TB Registry for the years 1989–1999, and a

search of medical record discharge diagnoses from 1980 to 1999.Cases were only included where both charts and radiographs wereavailable. The medical records were reviewed for age at presenta-tion, gender, sputum smear positivity for acid-fast bacilli (AFB),confirmation of diagnosis of TB, presence of extrapulmonary sitesof infection, and presence of underlying medical conditions.

Both authors reviewed the chest radiographs. All radiographswere assessed for lobar distribution of parenchymal opacities andcavities, as well as for lymphadenopathy, pleural effusions orthickening, and evidence of prior pulmonary TB (calcified paren-chymal foci, calcified mediastinal and hilar lymph nodes, scarring,volume loss).

Results

There were six pediatric patients from our institutionwith postprimary pulmonary TB (Table 1). Primary

ORIGINAL ARTICLEPediatr Radiol (2002) 32: 648–651DOI 10.1007/s00247-002-0769-5

Jason R. Shewchuk

Martin H. ReedPediatric postprimary pulmonary tuberculosis

Received: 14 May 2001Accepted: 1 May 2002Published online: 4 July 2002� Springer-Verlag 2002

J.R. Shewchuk (&)Department of Radiology, University ofManitoba, Health Sciences Centre,GA216-820 Sherbrook St., Winnipeg,Manitoba, Canada R3A 1R9E-mail: umshewc7@cc.umanitoba.caTel.: +1-204-7871328Fax: +1-204-7872080

M.H. ReedDepartment of Radiology, University ofManitoba, Children’s Hospital,840 Sherbrook St., Winnipeg,Manitoba, Canada R3A 1S1

M.H. ReedDepartment of Pediatrics and Child Health,University of Manitoba,Children’s Hospital, 840 Sherbrook St.,Winnipeg, Manitoba, Canada R3A 1S1

Abstract Background: Postprimarypulmonary tuberculosis (TB) isnot commonly seen in children.Objective: The purpose of thisstudy was to determine the radio-graphic findings and patient charac-teristics of pediatric postprimarypulmonary TB. Materials andmethods: We reviewed the clinicalcharts and chest radiographs in sixpatients. Results: The radiographicfindings of pediatric postprimarypulmonary TB include upper-lobeconsolidation and cavitation, multi-focal ill-defined airspace opacities,evidence of prior pulmonary TB,and apical pleural thickening.Pleural effusions and lymphadenop-athy are not commonly present.Although postprimary disease

typically does not affect young chil-dren, five of the children in thisseries were less than ten years ofage at the time of presentation.Conclusion: The possibility ofpostprimary TB should be con-sidered in pediatric patients at riskfor this disease who present withupper-lobe pulmonary consolidationand cavitation. These patients arehighly infectious and early recogni-tion and treatment can limit trans-mission of TB.

disease was documented in the chart at least 14 monthsearlier (range 14months to 4 years) in five patients. In oneother patient the diagnosis of primary TB was inferredfrom radiographic findings of prior disease (calcifiedprimary focus and calcified mediastinal lymph node).

Treatment of primary disease was well documented intwo patients. Patient 1 received 9 months of isoniazidand three months of aminosalicylic acid. Patient 3 re-ceived 9 months of both isoniazid and rifampin. Patients4 and 5 were asymptomatic at the time of their primarytuberculous infection and did not receive treatment.Both were contacts of known TB cases and had positiveMantoux tests and normal chest radiographs. No doc-umentation of treatment of primary TB was availablefor the two remaining patients. No patients presentedfor interval medical attention between primary andpostprimary disease.

Chest radiographs or reports were available from theepisode of primary disease in five patients. Two patientshad normal chest radiographs. The other three patientshad right upper-lobe consolidation and right-sided hilarand/or paratracheal lymphadenopathy. One of thesepatients also had a right-sided pleural effusion, and onehad accompanying right upper-lobe atelectasis. No chestradiographs demonstrated calcifications or cavitation.

At the time of presentation with postprimary diseasethe patients ranged in age from 5 to 14 years. TB wasdiagnosed by sputum culture in four cases, cerebralabscess culture in one case, and the presence of AFB inurine and a positive Mantoux test in one case. Threepatients were sputum smear positive for AFB.

Chest radiographs at the time of postprimary TBdemonstrated parenchymal opacities in all six patients(Table 1 and Figs. 1, 2). Three had multifocal ill-definedairspace opacities, suggesting endobronchial spread ofinfection (Fig. 2). Five patients demonstrated pulmo-nary cavities (Fig. 2). Two patients had apical pleuralthickening associated with upper lobe disease (Fig. 2a).No patients had radiographic evidence of lymphaden-opathy or pleural effusions.

Evidence of previous primary pulmonary TB wasseen on the radiographs of five patients. Two patients

Table 1. Clinical and radiographic features of children with post-primary pulmonary tuberculosis (AFB acid-fast bacilli, RUL rightupper lobe, LUL left upper lobe, LLL left lower lobe)

Patient Age(years)

Sex Sputumsmearfor AFB

Consolidation Cavitation

1 5 M Negative RUL RUL2 6 F Negative RUL, LUL RUL, LUL3 8 M Negative LUL None4 9 F Positive RUL, LUL RUL, LUL5 9 F Positive RUL, LUL, LLL RUL, LLL6 14 M Positive LUL LUL

Fig. 1a–c. Patient 2. A 6-year-old female with confirmed postpri-mary tuberculosis. a PA and b lateral radiographs of the chest showright upper lobe opacity with right hilar and paratrachealadenopathy. Primary tuberculosis. c PA chest radiograph 3 yearsafter a and b shows left upper-lobe opacity with cavitation and acalcified azygous lymph node (arrow)

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had calcified primary foci with ipsilateral calcified lymphnodes, one had a calcified primary focus with an ipsi-lateral calcified lymph node as well as a contralateralcalcified parenchymal focus, one had a calcified azygous

lymph node (Fig. 1c), and one had upper-lobe scarringand volume loss.

Other foci of postprimary TB included renal TB intwo patients diagnosed by the presence of AFB in theirurine and a cerebral tuberculoma in one other patient.

None of the patients were immunocompromised. Onepatient had an atrial septal defect at the time of primaryTB infection, but this subsequently closed spontane-ously. No other underlying medical conditions werepresent.

Discussion

Primary TB is generally a disease of children [2, 3, 4, 5,8]. Ninety-five percent of cases are pulmonary [10]. TB isusually acquired from an infectious adult or adolescentin the immediate household [6]. Up to 65% of affectedchildren are asymptomatic [7]. The chest radiographmay appear normal [2, 7, 8]. Of those who do have ra-diographic abnormalities, the predominant findings arelymphadenopathy and parenchymal opacities, present in62–93.5% and 68–78%, respectively [1, 2, 3, 4, 6, 7, 8, 9,10, 11, 12]. Pleural effusions and calcification are un-common findings [8, 9], and cavitation is rare, especiallyin immunocompetent children [6, 11, 12].

In 5–10% of children with primary pulmonary TB,the primary focus will enlarge and undergo caseous ne-crosis, forming a cavity [5, 8, 13]. When this occurs, it iscalled ‘‘progressive primary TB.’’ These children areusually quite ill [6]. None of the cases in this series fit thisdescription.

Postprimary (reactivation) pulmonary TB resultsfrom reactivation of a dormant focus of TB [2, 8]. Thisusually occurs in adults [1, 2, 3, 4, 8]. Most pediatriccases reported previously have been in adolescents [1, 2].However, five of our cases occurred in children youngerthan 10 years.

The typical radiographic findings of postprimarypulmonary TB are heterogeneous, often cavitary, opac-ities involving the apical and posterior segments of theupper lobes and the superior segments of the lower lobes[1, 2, 3, 4, 5, 12, 13]. The conventional theory to explainthis characteristic distribution has been that these re-gions of the lung have a higher oxygen tension and aretherefore more favorable for growth of the tuberculousbacillus. A more recent theory is that these regions havepoorer lymphatic drainage, and this predisposes them toreactivation [1, 3, 4, 5, 13]. All of our patients had upper-lobe consolidation, involving nine upper lobes. Onepatient also demonstrated lower-lobe consolidation, in-volving the posterior basal segment on the left.

Cavitation is the hallmark radiographic finding inpostprimary TB [3, 12]. This has been reported in ap-proximately 45% of cases [5]. Cavitation indicates ahigh bacillary burden and a high infectivity [2, 3, 12].

Fig. 2a–c. Patient 5. A 9-year-old female with confirmed postpri-mary tuberculosis. a PA chest radiograph shows bilateral upperand left lower-lobe opacities and cavitation. Multifocal ill-definedairspace opacities are present bilaterally. Right apical pleuralthickening is also present. b, c Axial CT scans confirm right upper-and left lower-lobe consolidation and cavitation and bilateral ill-defined airspace opacities

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Approximately 10% of patients have cavitation inatypical locations. Isolated lower lobe cavitation israrely the result of TB, although lower lobe involvementin the presence of upper-lobe cavitation is not rare [12].The radiographs of five of our patients demonstratedcavitation. Six upper lobes were involved. One patienthad lower-lobe cavitation in the presence of upper-lobecavitation. Only one patient did not have cavitation onchest radiographs. In 15–21% of cases cavitation leadsto endobronchial spread of infection, producing multi-focal ill-defined airspace opacities throughout the lungs[2, 3, 4, 8, 12, 13]. This was seen in three of the patientsin our series.

Evidence of previous primary pulmonary TB is seenon chest radiographs in 63% of patients with postpri-mary disease, including calcified parenchymal foci, cal-cified mediastinal or hilar lymph nodes, pleuralthickening or calcification, reticular scars, and volumeloss [5, 12, 13]. Evidence of primary TB was present infive of the patients in this series. There may be some biasin the number of patients with evidence of previous TBin our series as this was used as a criterion to establishthat the patient previously had TB in one case.

Pleural thickening, usually apical in location and as-sociated with parenchymal consolidation, has been de-scribed in 41% of patients with postprimary TB [13].This was seen in two of our patients. Pleural effusions

are seen in 6 to 18% of cases, and are usually small tomedium in size [2, 5, 13]. Effusions are less common inpostprimary than in primary disease [4]. Lymphaden-opathy is observed in only 5% of cases of postprimaryTB [5]. None of our patients demonstrated pleural ef-fusions or lymphadenopathy.

Renal TB is a late manifestation of the disease and isseen 5 or more years after the initial infection [10]. Twopatients in our series had renal TB.

Of 1,930 cases of active TB reported in Canada in1995, 1,448 were pulmonary, and 572 (39.5%) weresputum smear positive for AFB [10]. The three childrenwho were smear negative for AFB were the youngestpatients in our series, aged 5, 6, and 8 years. They mayhave been too young to produce a satisfactory sputumsample.

In summary, the radiographic findings of postpri-mary TB in the pediatric population are similar to thosein adults, namely, upper-lobe consolidation and cavita-tion, multifocal ill-defined nodular opacities, evidence ofprior pulmonary TB, and apical pleural thickening.Pleural effusions and lymphadenopathy are not com-monly seen. Postprimary TB can be seen in youngchildren, and consideration of this disease in childrenwho are at risk and present with upper-lobe consolida-tion and cavitation can aid in early recognition andtreatment of this disease, thus limiting further spread.

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