Clinical cases
DIFFERENTIAL DIAGNOSIS CHALLENGES IN A CASE OF SECONDARY SYPHILIS WITH NODULAR LESIONS

Summary
Syphilis is an infectious sexually transmitted disease in most cases, caused by Treponema Pallidum.
Case report
Female patient, age 58, from a rural area, hospitalized for a papulo-nodular eruption, with a diffuse spread on the body, with
elements ranging in size from 0.5 to 3 cm, some with a red-purple coloring which easily disappears after vitropressure, covered
with fine scales, while other lesions exhibit necrosis and ulcers on the surface. The lesions occurred 3 months before the time of
hospitalization, initially in the lower limbs, later comprising the other topographical regions.
One month before reporting to our clinic, the patient was hospitalized in Italy, where a skin biopsy was performed, the
suggested diagnosis being cutaneous lymphoma with plasmocytic differentiation.
We performed two skin biopsies (cutaneous lesions with different clinical aspects) to highlight the coexistence of the two
diseases (syphilis/lymphoma). The HP exam and immunophenotyping, together with serological explorations, excluded the
diagnosis of cutaneous lymphoma with plasmocytic differentiation, indicating the diagnosis of secondary syphilis with nodular
lesions.

Discussions
Although nodular lesions are usually found in tertiary syphilis, in very rare cases they may also be present in secondary
syphilis. In this situation, the differential diagnosis is made with lymphomas and pseudolymphomas, with deep fungal infections,
tuberculosis, skin metastases and leukemides. In some situations, secondary syphilis may mimic a granulomatous disorder, such
as lepromatous leprosy or sarcoidosis. The presence of granulomatous nodular lesions in secondary syphilis appears to be caused
by a hypersensitivity reaction of the body to the treponema or to be a consequence of the long-term evolution of the infection
leading to the tertiary stage.

Conclusions
Although extremely rare, secondary syphilis with nodular lesions poses multiple differential diagnosis problems. Confusion
with cutaneous lymphoma with plasmocytic differentiation may have dramatic conse-quences for the patient if an anticancer
treatment is administered.