Primary Localized Histoplasmosis: Atypical Presentation in Immunocompetent Patient - Case Report.

Sir,

Histoplasmosis is a mycosis that mainly affects the lungs, where it is usually asymptomatic and it is caused by Histoplasma capsulatum.[12345]

Cutaneous lesions occur in 4%–11% of patients and they are the result from secondary invasion of the skin in disseminated forms of infection.[23] Primary localized histoplasmosis (PLH), either primary cutaneous histoplasmosis or primary mucocutaneous histoplasmosis, without detectable systemic involvement, is an extremely rare clinical entity and the lesion probably occurred by traumatic implantation of the etiological agent in the skin or in the mucosa.[3]

We report a 67-year-old male patient who has had a history of painful plaque in the soft palate for 2 months. He has got it, 20 days after sawing and sanding the wood that was in the shed. At this location, he has confirmed seeing bats. He does not remember previous traumas in his mouth; history of diabetes mellitus, but it was compensated.

Dermatological examination revealed a white, cancriform-like plaque in a soft palate region, reaching the uvula [Figure 1]. Cervical lymph nodes were enlarged.

Figure 1

White plate, cancriform aspect, measuring approximately 3 × 4 cm in region of soft palate, reaching the uvula

Incisional biopsy of the plaque showed a granulomatous inflammatory process [Figure 2]. Sporulated structures (Grocott staining) suggestive of fungal infection were seen [Figure 3].

Figure 2

Microscopic examination by hematoxylin and eosin staining: granulomatous inflammatory process containing small and small intracellular round and ovoid organs (H and E 400×)

Figure 3

Histopathological: black round balls suggestive of fungal infection (Grocott 400×)

Immunodiffusion (ID) test for histoplasmosis was positive. Serology for leishmaniasis, VDRL, and anti-HIV 1 and 2, all negative. The antinuclear factor (ANF) was non-reactive. Chest X-ray showed normal. The culture for fungus and bacteria were negative.

Infectologist found no evidence of pulmonary disease or systemic histoplasmosis.

Curtis and Cawley (1947) were the first to report PLH. Since then, reports have been sporadic, the most recent being associated with a state of immunosuppression.[3]

Some authors have proposed the use of Wilson's criteria for the diagnosis of PLH,[3] which are as follows: 1) history of inoculation and exposure to the fungus with subsequent development of a cancriform lesion; 2) isolation in culture medium of the fungus; 3) regional lymphadenomegaly; 4) no clinical or laboratory evidence of previous systemic or pulmonary infection; and 5) positive serology. However, some reservations about the use of these criteria have been made: 1) the cancriform lesion is not the only presentation of the disease; 2) the primary lesion may or may not be accompanied by lymphadenopathy; 3) fungus culture may be negative in >90% of the immunocompetent cases; and 4) serologic titers may be unreliable and decrease or disappear with disease progression.

Histopathological evaluation shows a granulomatous inflammatory process with histiocytes containing small rounded organisms and small and intracellular ovoids (fungi). Grocott method also reveals these fungal structures,[2] but in immunocompetent patients, the number of fungi is small [Figures 2 and 3].

Microtraumas are frequent in the mouth and doorway lesions may go unnoticed by the individual, one of the hypotheses in our patient's case.

Differential diagnosis for PLH include the following: syphilis, leishmaniasis, squamous cell carcinoma, tuberculosis, paracoccidioidomycosis, and histoplasmosis.[3]

We used the treatment of choice for PLH, oral itraconazole.[3] There has been important improvement already in the first days of therapy.

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Conflicts of interest

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