PMC4712524_01
a Contrast CT shows enlargement of right testis with heterogeneous enhancement (arrow). b The testis shows a gray and yellow bulging tumor on cut surface. c The border of the tumor is infiltrative
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Fig1
A further pelvic computed tomographic scan revealed enlargement of the right testis estimated to be 4.5 x 4.0 cm in dimension, with heterogeneous enhancement, suspected of being a testicular tumor (Fig. 1a). On gross examination, the testis revealed an ill-defined, gray to tan, soft-tumor-like lesion measuring 3.3 x 3.2 x 2.6 cm (Fig. 1b, c).
a At low power, the testicular tumor shows an inflammatory lesion. b Higher magnification shows lymphoplasma cell and histiocyte infiltration. c Spindle cell proliferation in short fascicles is seen in areas. d Microabscess formation is focally evidenced. e Obliterative vasculitis is occasionally found. f In the periphery of the tumor, interstitial inflammatory cell infiltration and tubular atrophy are present (original magnification, H&E x 100 [a, c and f], x200 [b and d], x400 [e])
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Fig2
Histologically, the lesion disclosed dense lymphoplasma cell and histiocyte infiltration in the interstitium, as well as spindle cell proliferation (Fig. 2a, b, c). There were small foci of foamy histiocyte aggregation and microabscess formation in the lesion (Fig. 2d). Some of the blood vessels revealed obliterative vasculitis (Fig. 2e). The seminiferous tubules revealed atrophic change (Fig. 2f).
a Immunostain of syphilis shows spirochetes in the cytoplasm of histiocytes (1000 X, oil immersion). b DNA expression of TPmod1 is detected by PCR analysis. (Pos: positive control; Sample: tumor of the patient; Neg: negative control)
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Fig3
Invitrogen). No microorganisms were demonstrated by acid-fast, periodic acid-Schiff, Grocott-Gomori methenamine-silver stains, or Gram's stain. IHC with a rabbit polyclonal antibody against Treponema pallidum (dilution 1:100, Biocare Medical, Concord, CA, USA) displayed some spirochetes in the cytoplasm of histiocytes (Fig. 3a), highly suggestive of syphilitic orchitis. DNA polymerase I gene (Fig. 3b). Direct sequencing proved positivity for T. pallidum, which confirmed the diagnosis of syphilitic orchitis.