Radiological presentation of pulmonary mycosis

Fungi are simple vegetative structures; they lack chlorophyll and cannot conduct photosynthesis. They are characterized by the formation of filaments or hypae, which branch and intervene to form dense net of growth. This mat like growth made up of mycelium with its spores constitutes an irregular rudimentary plant called fungus. This is not differentiated into roots, stems or leaves. They are saprophytes as well as parasites, are extremely common and have worldwide distribution, only a few being pathogenic. Mycosis is acquired by inhalation of spores. They cause primary as well as secondary infections during the treatment of bacterial or viral infections. They are regarded as neither plants, nor animals but are placed in a separate group. The fungal infections are superficial as well as deep. The superficial infections involve skin; nail hands and keratin containing structures while the deep infections involves dermis, mouth, bones and viscera like lungs.

Beside tuberculosis, awareness about chest diseases is increasing and more non-tuberculous lung infections are being recognized – pulmonary mycosis is not uncommon; a clinical study was undertaken in Nishtar Medical College and hospital Multan. The incidence of pulmonary mycosis is 8.2% among the patients suffering from respiratory diseases and the incidence is higher in male as compared to female.

Radiology is of course has an important role in the diagnosis of pulmonary mycotic infection. A clinical suspicious following a radiograph gives suspicious of pulmonary mycotic infection. From the analysis of initial signs and there modifications in the course of disease, it is possible to identify some aspects strongly suggestive of the mycotic nature of the pulmonary lesions like rounded pneumonias; and hemorrhagic infection often complicated by cavitations with or without intracavitary nodule are the most suggestive aspects (Castagnone et al³).

The radiological findings in pulmonary aspergillosis can be homogenous consolidation, patchy consolidation or small circular shadows, irregular nodular infiltrates closely resembling pulmonary tuberculosis, and sometime a miliary spread. A common radiographic feature of opportunistic pulmonary aspergillosis is a rounded cavitary lesion with a nodule projecting into it giving appearance like “air crescent”, “meniscus, target”, “bulls eye” or penisula. There may be hilar lymph node enlargement.

In blastomycosis, which tends to occur in the upper lube, resemble bronchogenic carcinoma; in cryptococcosis the X-ray findings may include well-circumscribed rounded mass or mass like densities or pneumonia like appearance in the lower lube.

In histoplasmosis X-ray findings occurs as a single or multiple areas of pneumonic consolidation. The disease cannot be distinguished from pulmonary tuberculosis, nodular lesions are scattered in both lung fields calcification occurs in hilar lymph nodes. Pleural involvement may occur.

Coccidiodal pneumonia may occur and persists for months and sometime miliary spread also occurs. Radiologically the disease may resemble miliary tuberculosis. There may be cavitation with pulmonary infiltration. Since the changes are similar to those noted in pulmonary tuberculosis, mycotic infection and other chronic inflammatory diseases as well as neoplasm, the diagnosis must be based on mycogenic confirmation.

The following agents are used in the treatment of pulmonary mycotic infections; oral drugs i.e. polyene antibiotics, imidazole, paraentral drugs like fluconazole; local & parentral drugs like miconazole and combination of antifungal therapy i.e. quinolones and azoles.

Amphotericin B is the only recognized antifungal used in the treatment of mucormycosis and the various combinations of amphotericin B, Fluconozole and Travofloxacin or Ciprofloxacin are used. The combination of Fluconazole and a Quinolone has a marked effect on the outcome of murine pulmonary mucormycosis. The azoles especially fluconazole in combination with either trofloxacin or ciprofloxacin are effective in the treatment of mycosis (Sugar et al ²³)

The treatment of choice with oral agents is Ketoconazole. This drug has least side effects and patient’s tolerance is excellent. The drug is avoided in pregnancy because of teratogenic effect. Craig⁵ and Ritter²⁰ have recommended Ketoconazole as treatment of choice in aspergillosis. Kohono et al¹³ treated one case of aspergillosis effectively. Maeda et al¹⁶ also treated one case aspergillosis with ketoconazole effectively.

MATERIAL AND METHODS

The cases of pulmonary mycosis were isolated from respiratory diseases in the department of chest diseases and Tuberculosis, Nistar Medical college and hospital. The study was conducted over a period of 2 years. During this period 610 patients suffering from various respiratory diseases were admitted in the chest ward and 50 patients with positive sputum for fungus were isolated in this study. The patients who were admitted and the routine radiographs gave us suspicious of mycotic infection like consolidation without cavity or cavity having nodule in it, lung abscess, bronchiectasis malignancy, tuberculous infiltrations in the lungs, and pleural effusions, then further investigations done and confirmation was made. Cases negative for fungus in the sputum were excluded. The Assessment of all these patients was made through history, clinical examination, X-Rays and other relevant investigations like urine, complete blood, blood sugar, tuberculin test, sputum smear for AFB, skin allergic testing, bronchoscopy & pleural fluid cytology. A detailed history and examination was carried out in each case. Sputum specimen was examined for acid-fast bacilli, cancer cells and a culture for ordinary Micro Organism was carried out in every case. The specimens of sputum were sent to the department of microbiology for culture of the fungus. Those patients in whom a repeated positive culture for fungus was obtained, were examined daily. ESR, X-Rays skiagram of the chest was taken regularly to assess the progress of the disease.

Apart from sputum culture examination on sabourauds glucose Agar and broth media, other investigation like skin allergic tests for various fungi, Bronchoscopy, and in some cases pleural fluid cytology and pleural biopsy was done.

RESULTS

Thirty eight men and 12 women ranged from 17 to 85 years having different types of fungi were tabulated suffering from respiratory diseases. Thus the prevalence of pulmonary mycosis among the pulmonary disease cases is 8.2 percent and this prevalence is statistically higher in males as compared to females (P<0.01). This study shows that pulmonary mycosis is present in middle and old group (more frequently in 3^rd to 7^th decades) and about 82% fall in this range, 10% below the age of 20 years and 6% above the age of 70 years. The average age prevalence is 45.8 + 19 years.

Details of cases of pulmonary mycosis

Age	Sex	Occupation	Primary Disease	Infecting Fungus
30 years	Male	Shopkeeper	Upper zone infiltration (Tuberculous)	Mucor
60	‘’	Farmer	Bronchiec tasis	Aspergillus Niger
85‘’	‘’	Labourer	Lt. Sided infiltration (Tuberculous)	Candida albicans
20‘’	‘’	Student	Rt. Pneumothorax dieto (Tuberculous)	‘’
60	‘’	Shopkeeper	Rt. Upper zone infiltration (Tuberculous)	‘’
60	‘’	Labourer	Malignancy	‘’
75	‘’	Labourer	Bil. Infiltration (Tuberculous)	‘’
70	Female	Household	Bil. Pneumonia	‘’
80	‘’	Household	Malignancy	‘’
22	Male	Labourer	Rt. Sided infiltration (Tuberculous)	‘’
50	‘’	Hawker	Malignancy with pleural effusion	‘’
40	Female	Household	Bil. Infiltration (Tuberculous)	‘’
40	Male	Chowkidar	Rt. Pneumonia	Mucor
55	‘’	Labourer	Rt. Upper zone infiltration (Tuberculous)	‘’
70	Female	Farmer	Lt. Sided infiltration (Tuberculous)	‘’
30	Male	Labourer	Rt. Sided cavitary lesion	Asp. Fumigatus
60’	‘’	Carpenter	Lung abscess right	‘’
38’	‘’	Servant	‘’	‘’
21	‘’	Labourer	Rt. Upper zone infiltration (Tuberculous)	‘’
25’	‘’	Student	Bronchitechtasis	‘’
25	‘’	Vegetable seller	Bil. Infiltration (Tuberculous)	‘’
65’	‘’	Mason	Lung abscess right	‘’
40’	‘’	Shopkeeper	Mediastinal growth	‘’
65’	Female	Household	Pneumona Rt.	‘’
55’	‘’	‘’	Rt. Upper cavitary lesion (Tuberculous)	‘’

Table 1: Distribution of fungi in relation with different diseases

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Candida Aspergillosis Mucor-

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Pulmonary

Tuberculosis 24 2 3

Pneumonia 3 3 1

Malignancy 3 1 -

Lung abscess - 3 -

Bronchiectasis 1 2 -

Hydatid cyst 1 - -

COPD 1 - -

Cystic lung

disease 1 - -

Eosinophilia 1 - -

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This table shows that pulmonary tuberculosis was more prominent disease, in 24 patients candida was recovered, and in 2 aspergillosis and in 3 mucor detected. Pneumonia was underlying cause in 3 cases of candida albicans infection, 3 cases of aspergillosis and one case of mucor mycosis. Lung malignancy was underlying cause in 3 cases of candida infection and one case of aspergillosis. Lung abscess was cause in 3 cases of aspergillosis. While bronchiectasis was underlying cause in 2 cases of aspergillosis and 1 case of candida albicans. Hydatid cyst, COPD; cystic lung disease, Eosinophilia was underlying cause in candida infection.

Pleural effusion was detected in 6 (12%) patients. All were from candida albicans series. There were 4(8%) cases of pulmonary tuberculosis while in 2 (4%) cases the cause was lung malignancy.

Out of 35 cases of pulmonary candidiasis 17(48.57%) were living and 18(51.43%) were dead, out of 11 cases of pulmonary aspergillosis 9(81.81%) were living and 2 (18,18%) died while out of 4 cases of mucormycosis 2(50%) were living, 1(25%) died and 1(25%) was not traceable.

Table 2: Causes of Death

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Candida Aspergillosis Mucor

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Pulmonary Tuberculosis 15 0 1

Lung Abscess 0 1 0

Pneumonia 1 1 0

Lung malignancy 2 0 0

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Table 3: Percentage of Alive/Expired patients of different types of pulmonary mycosis

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Alive Expired Not Traceable

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Candida 17(48.57%) 18(51.43%) --

Aspergillosis 9(81.81%) 2(18.19%) --

Mucor 2(50%) 1(25%) 1(25%)

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DISCUSSION

Figure 1 and 2 show Bronchogenic Carcinoma. In this study 4 cases of Bronchogenic Carcinoma were detected and the fungus isolated was Cadida Albicans, also observed from Japan in Shimuzu et al²² series in 1993, bronchogenic carcinoma was associated with pulmonary Mycosis. Eight cases of pulmonary mycosis were evaluated in immuno-compromised patients in 1997 in Japan and the underlying diseases were lung cancer, post bone marrow transplant, Aids, and bronchial asthma. Urakaming etal²⁶.

Figure 3 and 4 present with lung abscess and 3 cases were observed in our study. In Tedder et al²⁵ study from North Carolina the pulmonary mycosis was associated with lung abscess. Figure 5 shows extensive advanced pulmonary tuberculoses with bilateral cavitary lesion. The fungus candida albicans, aspergillus and mucor were isolated in pulmonary tuberculosis. The parenchymal lesion may lead to fibrosis, cavitations or granulomatous nodules. There are frequently hilar lymph node involvement and occasionally pleural involvement occurs. In our series pleural effusion was detected in 6 cases, 4 from candida series and the underlying cause was pulmonary tuberculosis and in 2 cases the cause was lungs malignancy which is in agreement with Kado et al¹².

Figure 6 and 7 show intra cavitary fungus ball, observed in our study and the fungus isolated were aspergillus fumigatus. Figure 8 represents hydated cyst, being underlying cause and the fungus isolated was candida albicans. Figure 9 represents bilateral bronchiectasis, observed in 3 cases in our series, the fungus isolated was aspergillus and candida and this was also observed by Niki et al¹⁸ and Chern et al⁴. Figure 10 and 11 show magnified growth of candida albicans.

Pneumonia was underlying cause in 7 cases of pulmonary mycosis in our study, 3 from candida, 3 from aspergillosis and 1 from mucormycosis which has been also described by Bundgaard et al², Lake et al¹⁴ and Tedder et al²⁵. Fig. 12 shows profuse growth of mucormycosis. Figure 13 shows growth of aspergillus.

Pulmonary and extra pulmonary manifestations of aspergillosis, histoplasmosis and blastomycosis are reviewed in a paper published in 1997 (Urakaming et al²⁶) showing fungal pneumonias and is in agreement in our study having pneumonia presentation in 7 cases.

A common radiographic feature of opportunistic pulmonary aspergillosis is a rounded cavitary lesion with a nodule projecting into it. This appearance has been given a variety of names including “Air Crescent”, Meniscus, Target, and Bulls eye. And Penisula (Gross et al⁹, Gefter⁷ and Bolton et al¹. In our study one case of aspergilloma “cavity having fungus ball” is detected. The fungus isolated was aspergillus fumigatus. Radiological features of invasive pulmonary aspergillosis observed in 20 patients were reported in Italy in 1984 by Castagnone et al³, Wang et al²⁸ and McCaffery et al¹⁵. From the analysis of initial signs and there modifications in the course of disease, it was possible to identify some aspects strongly suggestive of the mycotic nature of the pulmonary lesions, like rounded pneumonia and hemorrhagic infarction often complicated by cavitation with or without intracavitary nodule are the most suggestive aspects (Castagnone et al³). In our study 11 cases of pulmonary aspergillosis are detected. Also presentation like pneumonia, lung abscess, bronchiectasis and lung cancer is described. Chest X-ray findings of aspergillosis is of two types: one was an air crescent sign which was noted in recovery phase from leukaemia and the other was gradually enlarging consolidation and progressed to labor pneumonia (Fugishitan et al⁶). In our study air crescent with fungal ball is observed in aspergillus infection.

The roentgenologic pattern of the pulmonary manifestation of candida species resulting in a rapid development of pulmonary cavitation with mycetoma-structures was described by Rix²¹ 1987 in 3 patients. This type of pattern by candida was not observed in our study. AIDS predisposes to pulmonary mycosis (Jones et al¹¹, Perrin et al¹⁹, Minamoto et al¹⁷ and Ritter²⁰.

A 59 years old woman with diabetes mellitus and rheumatoid arthritis was started prednisolone and she developed fever and bloody sputum and x-ray chest showed a massive shadow in the right lower lung filed. Aspergillus hyphae were detected from the bronchial brushing and pulmonary aspergillosis was diagnosed. Pneumonia like presentation is observed in our study, which is in agreement with Wakayama et al²⁷.

Invasive pulmonary aspergillosis (IPA) in the presence of hamatologic malignancies is increasingly common condition characterized by high morbidity and mortality. Plain chest films are a valuable tool for diagnosis but the radiologist must be familiar with the morphological features of the disease to interpret radiographic abnormalities of (IPA) from opportunities pneumonia (Zizzo et al²⁹).

Association of pulmonary mycosis with other diseases has been reported from the various countries like Japan in Shimuzu et al²² series, and the bronchogenic carcinoma was associated with pulmonary mycosis and in Italy Taviani et al²⁴ series the pulmonary mycosis was associated with lymphatic leukaemia. In Tedder²⁵ series from North Carolina, pulmonary mycosis was associated with lung abscess.

A case of pulmonary candidiasis occurred during therapy for tuberculosis pleurisy (Kado et al¹²), in our series pleural effusion was detected in 6 cases from candida series, and the underlying cause was tuberculosis and lung malignancy.

Allergic bronchopulmonary aspergillosis, an uncommon but potentially destructive aspergillus – associated pulmonary disease is characterized by recurrent episodes of pulmonary infiltrations and central bronchiectasis and may lead to irreversible fibrosis Niki et al¹⁸, Chern et al⁴.

In our series in 3 cases of bronchiectasis are detected, the fungus isolated was aspergillus and candida albicans.

Coccidiodal pneumonia may occur and persist for months. Sometime miliary spread may occur. Radiologically the disease may resemble tuberculosis and there may be cavitation. In histoplasmosis x-ray findings occur as single or multiple areas of pneumonic consolidation. The disease cannot be distinguished from pulmonary tuberculosis. Nodular lesions are scattered in both lung fields. Calcification may occur in hilar lymph nodes. Pleural involvement may occur. In our study coccidiomycosis and histoplamosis were not observed. In cryptococcosis the x-rays findings include well-circumscribed rounded mass or mass like densities or pneumonia like appearance in the lower lobes. In mucor mycosis the lesions like aspergillus may occur but less prominent. In chronic form of blastomycosis, the lesion resembles pulmonary tuberculosis. There is fibronodular appearance consist of a linear fibrotic strands and sometime mass like appearance which can resemble bronchogenic carcinoma. In our study, cryptococcosis, histoplasmosis are not detected. Pneumonia described by Niki et al¹⁸ one case, Castagnone et al³ 20 cases, Herbert et al¹⁰ one case, Greene et al⁸ one case, Ritter et al²⁰ which was also observed in 7 cases of our study.

In our study 50 patients had pulmonary mycosis of different types out of these 50 patients, 38 were males and 12 females, 35 had candida albicans, 11 aspergillosis and 4 mucor mycosis. The incidence was 8.2% among the respiratory diseases and statistically higher in male as compared to female (P<0.01). The age incidence was from 3^rd to 7^th decade and the mean age in female was higher as compared to female.

Average prevalence was in the age 45.8 + 19 years. Invasive pulmonary aspergillosis in hamatologic malignancies is increasingly common and chest radiographs are valuable tool for diagnosis for early interpretation and latter confirmation of mycosis. Thus decreasing the morbidity and mortality. The mean survival time was 18.4 + 13.5 months. Mean survival time of candida, aspergillus and mucor was 16 + 10.3; 25.2 + 10.3, 21 + 12.7 month respectively.

CONCLUSIONS

In this study, 50 patients with pulmonary mycosis of different types were isolated from 610 patients suffering from different respiratory diseases. Out of these 50 patients, 38 were males and 12 females. Further scrutiny showed that 35(70%) had candida albicans, 11(22%) aspergillosis and 4(8%) mucormycosis among the respiratory disease cases was 8.2 percent and the prevalence was higher in male as compared to female.

Radiology has important role in the diagnosis of pulmonary mycotic infection. A clinical suspecious following a radiograph give suspecious of pulmonary mycotic infection and moreover early suspecious and confirmation may reduce the morbidity and mortality of pulmonary mycotic infection but the radiologist must be familiar with the morpholigical features of the disease to interpret radiographic abnormalities.