The pathogenesis of acute and chronic filarial hydrocele is discussed in detail elsewhere [11, 12].
The following groups were characterized: (1) control (4 cases): symptomless individuals from which living AWs nonsensitive to antifilarial treatment were removed [17-20]; (2) patients with dead AWs in the PL (1 case); (3) acute filarial hydrocele (3 cases): patients with fluid accumulation in the tunica vaginalis cavity which appears within a few days after a nodule formation and resolves spontaneously up to 18 months ; (4) filaricele (20 cases): patients with chronic accumulation in the tunica vaginalis cavity of fluid composed of a combination, in different proportion, of transudate and nonmilky lymph from ruptured dilated lymphatic vessels .
This group was composed of patients without an earlier history of acute filarial hydrocele, but with lymphatic fistulae detected during surgery.
A remarkable finding was the identification of lymphatic stomata in acute filarial hydrocele (Figure 4).
Noroes and Dreyer  consider that filaricele is the prototype of the chronic condition occurring in endemic areas, referred to in the literature as "chronic filarial hydrocele," "chronic hydrocele," or simply hydrocele.
The present investigation covered very well-characterized clinical presentations of intrascrotal BF; some of them are seldom diagnosed even in a research setting, such as the acute filarial hydrocele. Some standpoints should be underlined: namely, (a) the identification of lymphatic stomata which is reported in filarial acute hydrocele for the first time; (b) the rarity in the AWs in PL, in spite of marked lymphangiectasia and the absence of Mf in the fluid from testicular tunica vaginalis cavity; (c) the apparent involvement of ELCs in filarial granuloma; (d) neoformation of lymphatic capillaries in filarial granuloma and in chylocele; and (e) the possible phenotypic transition of LECs into myofibroblasts in chylocele.
Dreyer, "Pathogenesis of filarial hydrocele: Risk associated with intrascrotal nodules caused by death of adult Wuchereria bancrofti," Transactions of the Royal Society of Tropical Medicine and Hygiene, vol.