Fig.65-A1
Protothecosis

In the lower leg of an older immigrant from Syria,living for a long time in Mérida / Venezuela, a tumor like swelling with a slightly elevated large ulcer is present showing a grey colour and haemorrhages. The patient refers that this skin lesion appeared the first time many years ago after bathing in a lake of an island in the Karibik. All kinds of treatment were useless. Several doctors suspected a mycetoma.

Fig.65-A2
Protothecosis

After the histological diagnosis a treatment with Amphotericin B was performed and after three months the healing of the infection was achieved as can be seen in this picture. Later, unfortunately a relapse took place, because the patient had refused a new intravenous therapy.

Fig.65-A3
Protothecosis

The biopsy shows in the slide with the HE stain large roundish elements of different sizes measuring up to 15 µ looking like fungus cells of Blastomyces dermatitidis and in addition some sporangia of different sizes.

Fig.65-A4
Protothecosis

The suspected fungal elements were Grocott positive and were arranged partly in clusters. The species of algae in humans belong to the genus Prototheca. The green algae, however to the genus Chlorella. The latter are pathogenic for animals. In our case the P. wickerhamii was the pathogenic species. The first cases of protothecosis were described in the sixties of the last century. In Venezuela our cases were the first to be described.

Fig.65-A5
Protothecosis

The sporangia mentioned in the legend of fig. 65-A3 show internal bodies. A large sporangium is seen here stained with the Gridley method and showing large internal bodies.