Filaments in Siderotic Nodules of Spleen in Cases of Splenomegaly of Unknown Origin.

Abstract

In the recent studies concerning primary splenomegaly, much attention has been given to the presence in the spleen of the siderotic, so-called Gandi-Gamna nodules. Several observers 1 , 2 , 3 , 4 , 5 claimed that these siderotic or iron pigment deposits in the spleen were the direct result of the growth of a fungus. They considered the threadlike structures found in the nodules to be mycelium and were able to recognize club-like branches and fructification organs. The cultivation of fungi from a number of spleens from cases of primary splenomegaly seemed to confirm these views. On the other hand, many of the German pathologists since 1920 as well as several recent investigators 6 , 7 believed that the filamentous structures composing the pigment deposits were degenerated tissue fibers.

We have made histological examinations of the spleens removed at operation from cases of primary splenomegaly and have compared the filaments found in the siderotic nodules as described by others, with the two varieties of fungi cultivated from the same spleens in this laboratory. 8 Upon close examination of sections stained in the usual manner certain structures were found in the pigmented areas which could be readily mistaken for the mycelium of a fungus. Two kinds of fibers were often present in the same area. One form appeared like wavy, branching threads of varying width (Fig. 1). The other kind, which was less likely to be mistaken for mycelium was composed of wider, more irregular, heavily pigmented rods (Fig. 2). The rods appeared to be irreguarly segmented and the ends showed jagged edges suggesting fracture surfaces of brittle fibers. Structures resembling conidia were also occasionally found in the nodules. They proved to be deposits of calcium and iron pigment. However, the appearance of the thread-like structures was different from the 2 varieties of fungi isolated from the same spleens 8 (Figs. 1 and 2). Moreover, siderotic nodules with similar filaments were found in spleens from cases of malaria, tuberculosis, kala-azar and syphilis as well as in an adenomatous thyroid gland.