Laboratory Studies
Although isolation of Klebsiella granulomatis has been reported, the organism is extremely fastidious and culture is beyond the capability of most laboratories. The easiest method to visualize the organism is via smears from the base of the ulcer. The organisms are seen within the cytoplasm of histiocytes. Characteristically, they exhibit bipolar staining, which has been likened to a safety-pin appearance, and are referred to as Donovan bodies. The organisms can occasionally be identified in tissue biopsy specimens with the use of special stains.
If a quick diagnosis is necessary, a smear can be performed. First, a cotton swab is gently rolled over the ulcer so as not to cause bleeding. The swab is then rolled over a glass slide. The slide is allowed to air dry and is then stained with Giemsa stain or pinacyanol to demonstrate Donovan bodies.
Alternatively, a crush preparation can be performed. A small piece of tissue should be obtained from the ulcer edge or base via punch biopsy, curettage, or a thin wedge resection. Next, the tissue is crushed between 2 glass slides, separated, and then air dried. A Wright-Giemsa, Warthin-Starry, toluidine blue, or Leishman stain may be used to demonstrate the Donovan bodies.
Lastly, a tissue biopsy specimen can be obtained; however, the organisms may be difficult to find in early or secondarily infected lesions, or on routine stained sections with hematoxylin and eosin. Thin, paraffin-embedded sections stained with Giemsa or silver stain may facilitate identification of the rod-shaped, encapsulated organisms within the macrophages.
Polymerase chain reaction techniques may be more sensitive; however, they are currently only used for scientific research.
An indirect immunofluorescent technique is available to test serum; however, it is not accurate enough for confirmatory diagnosis.
Culture of Klebsiella granulomatis from feces has been reported using a monocyte co-culture system and a modified Chlamydia culture.
Papanicolaou smears may identify Donovan bodies in patients undergoing routine cervical cytological screening.
Since granuloma inguinale is a sexually transmitted disease, a complete workup for other sexually transmitted disease should be considered.
Imaging Studies
If bony involvement is suspected in granuloma inguinale, radiography or other imaging studies are indicated.
Other Tests
Testing for other sexually transmitted diseases is warranted because multiple coexisting infections are common.
Histologic Findings
The epidermis displays acanthosis at the ulcer edge, with pseudoepitheliomatous hyperplasia variably present. A dense dermal infiltrate of histiocytes and plasma cells is present, with a scattering of small neutrophilic abscesses. The macrophages are large and vacuolated, and they contain intracellular bacilli (ie, Donovan bodies), which are best visualized using special stains such as a Warthin-Starry, Wright-Giemsa, or Leishman stain. Klebsiella granulomatis does not stain well with hematoxylin and eosin.
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Beefy-red penile ulcers.
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Courtesy of Hon Pak, MD.
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Courtesy of Hon Pak, MD.
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Courtesy of Hon Pak, MD.
