pathology of Granulomatous Lung Disease With Bacterial Cause

pathology of Granulomatous

Lung Disease With Bacterial

Cause

Mihan pourabdollah

MD.AP.CP.NRITLD

Context

• Granulomas are among the most commonly

encountered abnormalities in pulmonary

pathology and often pose a diagnostic

challenge.

DEFINITION AND TERMINOLOGY

• A granuloma is a compact aggregate of

histiocytes (macrophages).

• The histiocytes in granulomas are often

described as ‘‘epithelioid.’

• Epithelioid histiocytes have indistinct cell

borders and elongated, sole-shaped nucle.

DEFINITION AND

TERMINOLOGY

• Aggregation of histiocytes is the minimum

requirement of a granuloma.

• Regardless of whether the lesion also

contains necrosis, lymphocytes, plasma cells,

or multinucleated giant cells.

.

Step 1: Identifying Organisms

• Infection is the most common cause of

pulmonary granulomas.

• Carefully exclude an infectious etiology

before diagnosing a noninfectious

granulomatous lung disease.

APPROACH TO THE DIFFERENTIAL DIAGNOSIS OF

GRANULOMATOUS LUNG DISEASE

• Step 1: Attempt to identify an organism.

• Step 2: Look for histologic features of

noninfectious granulomatous diseases

(Table 2).

Organisms in Pulmonary

Granulomas:

What to Expect.

• The bacterial organism most commonly found

in granulomas of the lung are mycobacteria .

• Mycobacterium tuberculosis

• Nontuberculous mycobacteria (NTM) .

Organisms in Pulmonary

Granulomas:

What to Expect

• Other bacteria (Nocardia,actinomycetes and

Burkholderia ,brucella) may also rarely

cause granulomatous lung disease

MYCOBACTERIUM

Tuberculosis

MYCOBACTERIA

Tuberculosis

• The granulomas of tuberculosis are typically

necrotizing , but may be nonnecrotizing or a mix

of both types.

• poorly formed granuloma or less organized

macrophage infiltrate in immunocompromised

host.

• Small numbers of neutrophils may be present.

Nonnecrotizing granuloma

Necrotizing granuloma

Caseous Necrosis

MYCOBACTERIUM

Tuberculosis

• The granulomas of tuberculosis may be

randomly located or;

bronchiolocentric,bronchocentric,perivascular,

interstitial or alveolar .

• Involvement of blood vessels, less frequently

than in sarcoidosis.

• The histologic appearance of tuberculous

granulomas may be indistinguishable from those

of nontuberculous mycobacterial infection

Bronchiolocentric granuloma

MYCOBACTERIA

Tuberculosis

• Because the histologic features of

tuberculosis are not organism-specific,

the diagnosis rests on detection (and

subsequent speciation) of mycobacteria.

Acid fast stain

Nontuberculous Mycobacteria


• Mycobacteria other than M.TB complex

• More than 140 species

• A wide range of organ involvement

• Pulmonary infections ,most frequent

• Caused by

MAC(90%)and,abscessus,kansasii,fortuitum

complex,chelonei complex,malmoense


• NTM-related lung disease also occurs in

immunocompetent individuals without

preexisting lung disease.

Nontuberculous Mycobacteria In

immunocompromised patients

• collections of mycobacteria laden foamy histiocytes.

• poorly formed granulomas.

• the lack of any significant inflammatory response.

• Neutrophilic infiltrate may predominate

Mycobacteria in this form of NTM disease are numerous

and easy to find, and culture results are usually positive.


The hallmark of MAC infectionsin patients with HIV is abundant acid-fast bacilli within macrophages


In immunocompetent patients

• Granulomatous inflammation indistinguishable from

tuberculosis .

• Like tuberculosis, both necrotizing and nonnecrotizing

granulomas .

• Variable numbers of neutrophils may be present with central

necrosis

• The granulomas may be peribronchiolar.

• Cases with non granulomatous inflammation have also been

described.

Mycobacteria fortuitum and

chelonei

• Patients who take mineral oil for constipation

• Aspiration of these organism from gastric

contents where they are present.

• Cavitary exogenous lipoid pneumonia with

granulomatous inflammation and lipid and

mycobacterium laden giant cells in microscopy.

• Aggressive pneumonia , may need surgical

resection.

Middle lobe syndrome

• Middle lobe of right lung or lingula.

• Middle aged to eldery nonsmoker females.

• Macrophage receptor defect suppressing

phagocytosis of NTM colonizing these areas.

• Peribronchiolar granulomatous inflammation

associated with bronchiectasis.

• Acid fast bacilli are difficult to find

Middle lobe syndrome

Hot Tub Lung

• Young, immunocompetent.

• Significant long standing hot tub exposure.

• Pathology is that of hypersensitivity

pneumonitis.

• Nonnecrotizing granuloma around the airways.

• More areas of an exudative to organizing

pneumonia .

• Cultures of sputum and tub water are positive

for MAC.

Hot Tub Lung

Recommendations,Problems and

pitfalls

Using the Tissue Reaction as a

Clue

• Organisms must be sought in both necrotizing and

nonnecrotizing granulomas since they may be found in either

type.

• The search must be especially thorough in necrotizing

granulomas since these are more likely to yield an organism.

•

• Organisms are by far more common in the center of the necrosis

but may occasionally be found in the periphery of the necrosis

or even within the cellular granulomatous rim.

Histochemical Special Stains

for Organisms.

• GMS for fungi.

•

• ZN (cold kinyon modification) for mycobacteria.

• Modified acid fast such as Fite-Faraco for mycobacteria

and nonmycobacterial acid fast organisms

(nocardia,rhodococcus ,legionella micdadei).

• Tissue Gram stain

Examining Special Stains for

Organisms.

• Regarding the ZN stain, in most cases, mycobacteria are few

and difficult to find, partly because of the use of xylene in

routine processing.(over 100/ml is necessary) .

• Spending at least a few minutes at high magnification (x10

ocular lens, x40 objective) .

• constantly adjusting the fine focus to ensure detection of

organisms that appear only on certain planes.

• Others go further and use a high-power oil immersion

objective

Infectious necrotizing granulomas. A, Tuberculosis. Necrotizing

granuloma.


Organisms

• Mycobacterial organisms may occasionally be

seen with GMS stains in certain cases and

should not be dismissed as an artifact.

• ‘Infarctlike’’ necrosis may be seen in

granulomas caused by M tuberculosis.

Mycobacterium TB stained with

GMS


Organisms.

• Immunohistochemical techniques are more

sensitive and specific but have their limitations.

• The auramine/auramine-rhodamine

fluorescence technique, more sensitive than

conventional acid-fast stains but positive result

sould be cofirmed by acid fast stain.

Immunohistochemistery

Fluorescent stain

How to Report the Presence of

Organisms

• The subtyping of infectious mycobacterial or

fungal disease ( progressive primary tuberculosis

versus secondary tuberculosis, etc.) often

requires clinical and radiographic information

that is usually unavailable to the pathologist.

•

• Therefore, for the purposes of the pathology

report, describing the tissue reaction and stating

the organism present is sufficient in most

instances.

differentiation between tuberculous

and nontuberculous mycobacteria

• Unfortunately, the morphologic appearance of

mycobacteria on histologic sections is not reliable for

speciation.

• The published literature on speciation of mycobacteria

by using microscopic morphologic features of the

organisms is based mostly on smears made from

microbiologic cultures rather than formalin-fixed,

paraffin embedded histologic material

differentiation between tuberculous and

nontuberculous mycobacteria

• Currently, the only definitive methods of mycobacterial

speciation are microbiologic culture and molecular methods

such as the polymerase chain reaction (PCR) .

• In most cases, speciation is not a problem because culture

test results are also positive , even when special staining of

histologic material shows negative results..

Eight Week Growth of Mycobacterium

tuberculosis on Lowenstein-Jensen Agar

differentiation between tuberculous

and nontuberculous mycobacteria

• When results with histologic special stains are

positive but those of cultures are negative, or

when biopsied tissue was not submitted for

culture, PCR is the only means

What should we do if special

stains are negative

Special Stain negative

granulomas

• Often, organisms are not found within granulomas

despite a meticulous search. Even in necrotizing

granulomas, this is a fairly frequent scenario.

• Special stain negative cases might represent infectious

granulomas in which the organism has been killed or

removed by immune system


granulomas

• The most productive next step for the pathologist is ;

• to reevaluate the special stains.

• If the necrotic portion of the granuloma is not represented on

the slide with the special stain, it may be productive to recut

the block and repeat the stain.

• If some blocks with necrosis are not initially stained with

special stains, staining these may also be productive.

• Ulbright and Katzenstein showed that examining 2 blocks with

necrosis is adequate in most cases.

How to report special staining

negative granulomas


granulomas

• In such cases, we recommend issuing a descriptive diagnosis

including the presence/absence of necrosis and the absence of

identifiable organisms.

• In the case of necrotizing granulomas, a comment such as ‘‘the

etiology is most likely infectious despite negative special stains’’

may be appropriate

Role of PCR and Other Molecular Methods

for Detection and Speciation of

Mycobacteria.

• Molecular test is at least as sensitive as

microbiologic cultures for the detection of

mycobacteria in formalin-fixed tissues and is

more sensitive than ZN staining

• It is also possible to determine the species of

organisms by this method.

Pulmonary

nocardiosis

Nocardia• Genus : aerobic Actinomyctes

G+ branching filamentous bacteria

• Subgroup: aerobic nocardiform

actinomycetes

-Mycobacterium

-Corynebacterium

-Nocardia-Rhodococcus

-Gordona

-TsukamurellaDr.T.V.RaoMD

59

Dr.T.V.RaoMD

60

What are Nocardia

• Nocardia is a genus of weakly

staining Gram-positive, catalase-

positive, rod- shaped bacteria. It

forms partially acid- fast beaded

branching filaments.

Nocardia stained with GMS

Diagnosis

Respir Med 2003; 97:709-717

Stellate Granuloma

Nocardia

Nocardia

Microbiology

• Branching,

beaded,

filamentous

bacteria

• Can cause

"Sulfur

granules" like

actinomycosis,

in nocardial

mycetomas.

• Stains acid fast

Actinomyce

s.

Dr.T.V.Rao

MD

8

Microscopy and Culturing essential

for establishing Diagnosis

Dr.T.V.RaoMD

70

Pulmonary melioidosis

Introduction

• Melioidosis is an infectious disease caused by a Gram-negative bacterium.

• Melioidosis, also called Whitmore's disease, is an infectious disease caused by the bacterium Burkholderia pseudomallei.

• Melioidosis is primarily a disease of rats, but also occurs in guinea pigs and rabbits.

Clinical manifestation

• Pulmonary infection

• Skin ulceration

• Lymphadenopathy

• Manifestations are exacerbated long after the exposure; hence called as Vietnam time bomb disease.

Types of melioidosis

a. Acute melioidosis:

• It is characterized by development of a nodule at the site of inoculation of the bacteria in the skin.

• The bacteria can subsequently spread, causing secondary lymphangitis, regional lymphangitis, fever, and myalgia.

• Acute melioidosis may progress rapidly to acute septicemia with high mortality rate.

• Acute blood stream infection is most commonly seen in patients with HIV, diabetes, renal failure, etc. The condition results in septic shock.

b. Pulmonary infection:

1. The condition is associated with high fever, headache, chest pain, anorexia, and general myalgia.

2. Nonproductive or productive cough with normal sputum is typical manifestation of this condition.

c. Chronic suppurative infection

1. It is associated with multiple caseous or suppurative foci of infection in several organs including joints, skin, lymph nodes, spleen, lungs, liver, and brain.

2. It manifests as mild bronchitis to severe pneumonia.

3. Bacteria remain as intracellular pathogens of the reticuloendothelial system, which contributes to long latency and reactivation of the infection.

Gram stain

• Gram stain:

• B. pseudomallei is a Gram-negative bacillus.

• Measures about 2–5 μm in length and 0.4–0.8 μm in diameter.

• It frequently does not show bipolar-staining on Gram stain, but it is often pleomorphic and usually stains slightly unevenly.

Culture

• B. pseudomallei is not fastidious and grows on a large variety of culture media (bloodagar, Chocolate agar, MacConkey agar, etc.).

• Ashdown's medium may be used for selective isolation.

• Cultures typically become positive in 24 to 48 hours

Colony morphology:

• Smooth, creamy, white colonies on BA at 24 hrs

• Some may be mucoid or become dry and wrinkled at 48 - 72 hrs

• Pink colonies on MA agar at 24 - 48 hrs or colorless colonies at 48 hrs

Selective medium (Ashdown medium)

• Contains crystal violet and gentamicin as selectiveagents.

• It is also enriched with 4% glycerol, which isrequired by some strains of B. pseudomallei togrow.

• It usually produces flat wrinkled purple colonies.

• Colonies will also exhibit an earthy odor.

• The colony appears irregular-edge, rough and palepurple.

Biochemical test

• Catalase = Positive

• Oxidase = Positive

• Indole = Negative

• Motility = Positive

• Triple Sugar Iron (TSI) = K/NC

• Colistin/Polymyxin B = Resistant (no zone)

Thank You

pathology of Granulomatous Lung Disease With Bacterial Cause

Documents