A Rare Case of Aspergillus Involvement in a Kidney Transplant Recipient: Thyroiditis

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To the Editors: Aspergillus spp. generally cause infections with high morbidity and mortality rates in immunosuppressed individuals. Patients who receive chemotherapy for malignancy, have bone marrow or solid organ transplants, have neutrophil dysfunction, or are neutropenic (due to congenital or acquired bone marrow failure) are at risk for Aspergillus infection.1 Although lung involvement is most common, it can also affect different organs through hematogenous or lymphatic spread, as well as by direct spread from adjacent tissue. A 12-year-old male patient, who underwent kidney transplantation due to chronic renal failure caused by focal glomerulosclerosis, was admitted to our hospital with complaints of fever and severe frontal headache 45 days after the transplantation. The patient received intravenous meropenem, vancomycin, liposomal amphotericin B and trimethoprim-sulfamethoxazole due to the detection of abscess formations in brain magnetic resonance imaging. During follow-up, the patient developed swelling in the neck. Thyroid ultrasonography (USG) revealed ~25 × 21 × 24-mm hypoechoic solid thyroid nodule with irregular borders causing a bulge in the capsule in the inferior right thyroid lobe and a heterogeneous appearance with central and peripheral vascular signals in Doppler USG (Fig. 1A). Thyroid function tests are given as follows: TSH, <0.01 mIU/L (0.51–4.3); free T4, 2.8 ng/dL (0.93–1.63) and free T3, 2.96 ng/L (2.56–5). The patient had subclinical hyperthyroidism. Thyroid fine needle aspiration biopsy revealed numerous neutrophil leukocytes, thyrocytes and hyphae structures related to fungal infection (Fig. 1B). Intravenous voriconazole was added to the treatment. Intravenous liposomal amphotericin B treatment was discontinued at week 40. He was discharged with oral voriconazole at week 45 of his total treatment. Monthly thyroid USG checks are performed, and in the fourth month after discharge, ~7.5 × 9.5 × 8.5-mm irregularly shaped hypoechoic heterogeneous area with unclear borders was detected in the inferior right thyroid gland. The patient is being followed up with oral voriconazole treatment without sequelae.FIGURE 1.: A: Thyroid ultrasonographic examination revealed a hypoechoic, heterogeneous solid thyroid nodule measuring ~25 × 21 × 24 mm in the right thyroid lobe.B: The conventional smear and Pap stain revealed numerous neutrophil leukocytes, some atypical-looking thyrocytes and septate hyphae indicative of fungal infection.The thyroid gland is resistant to infections with some features, such as the structure of the capsule, the high iodine content, the high blood flow, hydrogen peroxide production and lymphatic drainage. Thyroiditis caused by fungal infection is extremely rare.2 Aspergillus thyroiditis is a postmortem diagnosis in immunocompromised patients with a diagnosis of disseminated invasive Aspergillus or a high suspicion of fungal infection.3,4 Our case is the first case of Aspergillus thyroiditis in a child who underwent kidney transplantation in the literature. Patients are usually asymptomatic or have nonspecific symptoms. The most common symptoms are fever, thyroid sensitivity and neck pain. Rarely, it may cause airway compression and/or esophageal obstruction. Most patients do not have clinical or laboratory findings suggestive of thyroid dysfunction. Hori et al5 reported that of 13 postmortem cases of Aspergillus thyroiditis, 11 were asymptomatic. Thyroid gland enlargement was detected in one patient, and airway obstruction was observed in another patient.5 Although treatment guidelines recommend monotherapy such as voriconazole or amphotericin B, combination treatments have also been reported in resistant cases.4 We also used dual therapy due to disseminated Aspergillus. As a result, early diagnosis and rapid initiation of empirical treatment are life-saving in immunosuppressed patients with Aspergillus.

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