A case of secondary syphilis presenting as multiple pulmonary nodules
A 51-year-old heterosexual male with no significant medical history presented with multiple pulmonary nodules on a plain chest radiograph. The nodules were detected during an evaluation for right pleuritic chest pain, fever, and myalgia that started 2 weeks earlier. The patient denied weight loss, respiratory, or gastrointestinal symptoms.\nA physical examination revealed a normal body temperature, normal breath sounds, no mucosal or genitourinary lesion, but an erythematous papular rash on the trunk, right cervical, and bilateral inguinal nontender, nonmovable lymphadenopathy was noted. Laboratory tests showed no leukocytosis, normal alkaline phosphatase levels, and a normal urinary analysis. However, the erythrocyte sedimentation rate, > 120 mm/hr (normal range, < 9), high sensitivity C-reactive protein, 4.8 mg/dL (normal range, < 0.3), γ-glutamyl transpeptidase, 73 IU/L (normal range, < 50), and alanine aminotransferase, 55 IU/L (normal range, < 50) were elevated. Carcinoembryonic antigen, carbohydrate antigen 19-9, and prostate specific antigen were within normal ranges. Human immunodeficiency virus (HIV) testing was negative.\nThe Venereal Disease Research Laboratory (VDRL) test was positive. A diagnosis of syphilis was suspected; fluorescent treponemal antibody-absorption (FTA-ABS) and VDRL titers were assessed, resulting in reactive FTA-ABS immunoglobulin M, immunoglobulin G, and a 1 : 64 VDRL titer. A plain chest radiograph and computed tomography (CT) scan showed multiple variably sized nodules in both lungs, suggesting the possibility of a hematogenous metastatic malignancy (). Screening tests for malignancy including gastrointestinal endoscopies, bronchoscopy, and CT scans of the neck, abdomen, and pelvis revealed only cervical and pancreatic lymphadenopathy. Positron emission tomography CT scanning was performed and showed hypermetabolic lesions, including the multiple pulmonary nodules, as well as the cervical and pancreatic lymph nodes, with no other organ involvement.\nThe standardized uptake values of the pulmonary nodules were from 4.37 to 5.59, strongly suggesting a malignancy (). A pulmonary malignancy was suspected and percutaneous needle aspirations of the pulmonary nodules and inguinal lymph nodes were performed. The cytopathological examination showed only many neutrophils and lymphocytes.\nAdditional history revealed that the patient had sexual contact with a prostitute 8 weeks previously and a painless genital ulcer developed about 6 weeks earlier, which disappeared spontaneously. A generalized erythematous papular rash appeared on trunk for 1 week that did not itch. Thus, the history and laboratory findings were compatible with secondary syphilis.\nBecause pulmonary involvement in secondary syphilis is extremely rare and the radiological findings suggested malignancy, a pulmonary malignancy was still strongly suspected. Thus, a video-assisted thoracoscopic surgical lung biopsy and cervical lymph node excisional biopsy were performed. Histopathological examination of a pulmonary nodule showed central necrosis with abscess formation and the infiltration of plasma cells and lymphocytes, with fibrosis in the periphery, but no evidence of malignancy or other specific pulmonary diseases ().\nClinical information and laboratory data, including the history, physical findings, and the reactive FTA-ABS and VDRL, supported a clinical diagnosis of secondary syphilis with multiple pulmonary nodules. Thus, the patient was treated with 2.4 million units of benzathine penicillin G, injected intramuscularly. The skin lesions and lymphadenopathy resolved after 2 weeks. A follow-up chest CT scan after 1 month showed improved pulmonary nodules, which had nearly disappeared at 10 months (). The VDRL titer decreased to 1 : 2 after 3 months and was nonreactive after 10 months.