244 REPORT OF THE HARVARD AFRICAN EXPEDITION 
any infected with parasites, and we have only found filarial embryos in Simulium 
damnosum in localities where Onchocerca infection was present. 
Thus in the same region in Liberia where infected Simuliwm were found (as 
well as in adjacent territory), we discovered individuals with tumors caused by 
infection with Onchocerca. Photograph No. 180 illustrates the tumor of the 
first case encountered in Liberia. The patient (Case 340) was a large, well- 
developed and well-nourished native. He complained of some pain in the right 
side of his chest. On the right side of the chest wall, in the axillary region, be- 
tween the sixth and seventh ribs, was a projecting tumor about the size of a 
hen’s egg located in the subcutaneous tissue, and firm to the touch. The skin 
over the tumor was not adherent and the tumor was so loosely attached as to be 
freely movable. On palpation it was found to be hard, slightly lobulated and 
not apparently tender. The skin above the tumor appeared to be normal. 
Microscopical examination of the blood from the ear and of a section of the skin 
made from a small papule on the wrist did not show any parasites. However, 
microscopical examination of a thin section of the skin immediately over the 
tumor revealed numerous motile embryos of Onchocerca, — the forms which are 
diagnostic of the infection. Sometimes the parasites are seen still enclosed in a 
sheath of the ovum (No. 183). 
Pathology. This tumor on removal measured 2.5 em. long and 12 mm. 
wide. It was enclosed in a smooth, connective tissue capsule, grayish white in 
color and not very vascular, but a few small blood vessels could be seen with 
a hand lens. On cut section, the capsule was about 2 mm. in diameter. At- 
tached to this main portion of the tumor was a smaller growth, 11 mm. in 
diameter, with a somewhat more vascular thin capsule. The cut section of both 
of the tumors was yellowish gray, the center becoming more orange in color. 
The center of the tumor was of softer consistency than the periphery. From the 
center of the nodules were expressed pieces of the adult parasites with embryos 
and ova. The ova have a very thin outer membrane and within the embryos 
may be seen in various stages of development. ‘Two types of larval forms are 
found free: larger, palely-staining forms, and smaller, more compact ones with 
deeply-staining nuclei. 
Tumors of similar appearance, varying in size from about 2 to 6 em. in di- 
ameter were removed from the subcutaneous tissue from six patients. Other 
cases were seen elsewhere in Liberia and about Leopoldville in the Belgian Congo. 
At Leopoldville, through the courtesy of Dr. Van den Branden and Dr. Duren we 
were permitted at their clinic to examine seven such cases and to remove tumors 
from three of these patients. Portions of all of them were immediately placed in 
Zenker’s solution or in formalin. The onchocercal tumors are commonly located 
about the chest wall, particularly in the lateral regions, occasionally on the dor- 
sum. They are also found in the neighborhood of the joints, more rarely in the 
axilla. As a rule, they are more firm at the periphery, but there are often soft 
areas in the more central portions, particularly in those areas which have a 
yellowish or orange color. It is in these soft areas or cavities that the adult 
parasites are particularly found. 
