CASE PRESENTATION

A 60 year old female diagnosed with Ca Breast with no metastasis underwent right modifi ed radical mastectomy (MRM). She had received adjuvant chemotherapy with 4 cycles of adriamycin and cyclophosphamide, and 3 weekly doses of paclitaxel aft er which she developed neuropathy and was switched to docetaxel. The last cycle was administered 2 weeks ago. She came back with complaints of fever for 2 weeks and cough for 2 weeks.

According to the pati ent, she was in her usual state of health 2 weeks back. Then she developed intermitt ent high grade fever not associated with chill and rigors, myalgia and arthralgia, relieved by taking anti pyreti cs. For her fever, she went to a periphery hospital, initi al work up was consistent with UTI and she was treated with ciprofl oxacin. Her chest X-Ray at that ti me was normal (Fig.1). But her fever persisted and she developed cough dry in nature aggravated at night and associated with shortness of breath on moderate exerti on. There was no history of weight loss, night sweats, abdominal pain, diarrhoea, burning micturiti on, haematuria or any other complaint. There was no history of exposure to tuberculosis or any familial disease. She had signifi cant history of exposure to birds at home.

Physical examination was unremarkable. On chest auscultation she had harsh vesicular breathing with occasional coarse crepts. Rest of her systemic examination was unremarkable. Lab parameters were also within normal limits. Repeat Chest X ray was done which showed diffuse opacities in both lungs which were reported as most probably metastatic lesions (Fig.2). But as the patient was running fever, we started her on tazocin 4.5 gm I/V 8 hourly to treat any superimposed infection. On Day 4 of Piperacillin/Tazobactum (Tazocin), her CXR was repeated, which was improving. However her fever was not settling down. Meanwhile, a contrast enhanced CT chest was done which showed diffuse bilateral nodular densities, suggestive of metastatic lesions (Fig.3). Bronchoscopy and Bronchoalveolar Lavage was performed, and was sent for C/S. Culture of bronchoalveolar lavage grew klebsiella. It was resistant to ciprofloxacin and sensitive to Piperacillin/Tazocin, Cefoparazone + salbactom, Imipenem, Amikacin.

Cytology came out to be negative. Infectious Diseases consult was taken. They advised levofloxacin for double coverage. On Day 3 of levofloxacin, she defervesced. I/V antibiotics were discontinued and she was discharged on oral levofloxacin. Then she completed her adjuvant chemotherapy. Her contrast enhanced CT chest was repeated after two months that showed marked reduction in all lesions (Fig.4). Patient was kept on three monthly follow ups

COMMENTS

1. INFECTIOUS DISEASE CONSULTANT’S PERSPECTIVE

Determining aetiology in cases of pneumonia is always a clinical challenge. A microbiologic diagnosis is confirmed in only 60% of cases in research studies that use specialized test to detect various pathogens as discussed below.

In a population based study conducted in Spain on 700 patients with clinical diagnosis of pneumonia, the aetiology was determined in only 55.7% of the patients.[1]. In another study conducted in Canada on 507 patients, despite considerable efforts, the aetiology could be determined in only 48.4% of the cases.[2] In another prospective study conducted in Spain to determine the aetiology and incidence of pneumonia in immunocompromised patients, the aetiology could be determined in only 44% of the immunocompromised patients.[3] The diagnosis of atypical pathogens requires extensive microbiological, serological and molecular tests which are unfortunately not available in our country. In this case, although Klebsiella pneumonia was isolated in culture and it was sensitive to piperacillin/ tazobactum, the patient received piperacillin/ tazobactum for 21 days in adequate dose with partial response. In patients who are immunocompromised, there is always a chance that the infection may present in an atypical way though in most of the cases these pathogens cause mild symptomatic disease in immunocompetent patients. The fact that patient responded to levofloxacin but not to beta lactam gives a supportive evidence that this patient had pneumonia with organism difficult to grow in culture or there is a possibility that she may have coinfection. Since patient gave significant history of exposure to birds and exposure to birds can lead to highly pathogenic avian influenza, Chlamydia psittaci, pulmonary cryptococcosis and histoplasmosis associated pneumonia especially in immunocompromised patients. Because this patient responded to quinolones and no antifungal or antiviral agent was prescribed, we can assume that the infection was caused by bacteria which was difficult to grow in culture but was sensitive to levofloxacin.

2. RADIOLOGIST’S PERSPECTIVE

The four most common anatomic sites of distant metastases in carcinoma of breast are bone (41.1%), lung (22.4%), liver (7.3%), and brain (7.3%). Typical radiologic findings of a pulmonary metastasis include multiple round variable-sized nodules and diffuse thickening of interstitium. These nodules are of variable sizes, a feature more consistent with metastasis. Other differentials depending upon the site of nodules may be fungal infections, sarcoidosis, lymphoma, Kaposi sarcoma, respiratory bronchiolitis, hypersensitivity pneumonitis. These pulmonary nodules were of soft tissue density and showed enhancement in post contrast study. Our patient was a known case of breast carcinoma. Keeping in view history and radiological features of diffusely spread pulmonary nodules of variable sizes, a diagnosis of metastasis was made. However, after bronchoalveolar lavage klebsiella grew in culture, and diagnosis of klebsiella pneumonia was established. Since she did not respond to initial antibiotic treatment and keeping in view the history of birds at home, a diagnosis of atypical pneumonia was made and quinolone was added. It is very interesting to note here that radiological features of atypical pneumonia include enhancing consolidations, poorly marginated low-attenuation areas with or without small air-containing cavities, scattered enhancing linear branching structures representing pulmonary vessels in atelectatic or consolidated lung, pulmonary gangrene, coalescence of multiple small abscesses into a large cavity, large-vessel thrombosis and pleural effusion and/or empyema. To our knowledge, no case has been reported in the literature demonstrating diffuse pulmonary nodules in a patient of atypical pneumonia. However, patient responded well and a re-scan of chest showed marked regression of pulmonary nodules in size and number.

3. MEDICAL ONCOLOGIST’S PERSPECTIVE

This was a very unusual presentation of pneumonia, and its radiological appearance was suggestive of metastasis. Our patient had node negative disease (T2N0M0) that is stage IIA, which has a low risk of recurrence and is associated with an overall survival of 81%[4]. On the other hand, in triple negative breast cancer, risk of relapse is high in first 3 years post treatment[5]. However being on chemotherapy and having a short history of current illness, an infectious etiology could not be ruled out completely

CONCLUSION

Immunocompromised patients are more at risk of developing infections with unusual presentation. Thorough checkup including history, examination, labs and imaging should be carried out in such cases for evaluation and management.

References

• 1. Capelastegui A, Espana PP, Bilbao A, Gamazo J, Medel F, Salgado J, et al. Etiology of community-acquired pneumonia in a population-based study: link between etiology and patients characteristics, process-of-care, clinical evolution and outcomes. BMC Infect Dis.2012; 12:134
• 2. Marrie TJ, Poulin-Costello M, Beecroft MD, Herman- Gnjidic Z. Etiology of community-acquired pneumonia treated in an ambulatory setting. Respir Med. 2005 ; 99(1):60-5.
• 3. Sousa D, Justo I, Dominguez A, Manzur A, Izquierdo C, Ruiz L, et al. Community-acquired pneumonia in immunocompromised older patients: incidence, causative organisms and outcome. Clin Microbiol Infect. 2012; 19(2):187-92.
• 4. www.cancer.org/cancer/breastcancer/detailedguide/ breast-cancer-survival-by-stage
• 5. Triple negative breast cancer –prognostic factors and survival. Tanja Ovcaricek, Snjezana GrazioFrkovic, Erika Matos, et al, Radiol Oncol. 2011 March, 45(1):46-52