Coccidioidomycosis, a fungal infection that is also endemic in southwestern United States, and myospherulosis
, an iatrogenic condition related to application of nasal "packing," may be considered in the differential diagnosis of rhinosporidiosis.
Myospherulosis was first described in Africa by McClatchie et al. The name was used based on the suspicion that this may be a curious new fungal infection.
The pathogenesis of myospherulosis was confirmed experimentally by Rosai and Wheeler et al, who reproduced it by incubating human erythrocytes at body temperature with tetracycline ointment, lanolin, petrolatum, and liquefied human fat.
This is a retrospective study reporting on the first finding, to our knowledge, of myospherulosis in renal cell carcinomas.
Myospherulosis was found in 8 men and 2 women, with 3 tumors on the left side and 7 on the right side.
The Table shows the occurrences of myospherulosis in the different types of renal cell carcinomas.
Myospherulosis was seldom seen in the other types of tumors, except in 2, where one myospherule could be identified in each case.
They were divided into 2 groups (stage 1 and above stage 1) and tested against the finding of myospherulosis. Seven tumors at stage 1 contained myospherules.
The finding of myospherulosis was further tested against the cell types, stages (1 against above 1), and nuclear grades using logistic regression.
Our findings confirm that myospherulosis is seen in renal cell carcinomas.
Our results show that myospherulosis is associated with the clear cell type of renal cell carcinoma and higher nuclear grade; however, since they are strongly related, only the former remains significant when both are included in the logistic regression.