Acute Invasive Fungal Thyroiditis – A Catastrophic Event Post-Renal Transplant

Dear Editor,

Fungal thyroid infections are rare but more common in immunocompromised individuals. Mucormycosis, caused by Mucorales species, is aggressive and primarily affects those with conditions like diabetes, hematological malignancies, or organ transplants.^1,2

Mucorales spp. fungal thyroiditis is exceptionally rare with just 11 reported cases. Only two cases involved isolated thyroid disease: one in an Indian renal transplant patient and another in a Polish child with acute lymphoblastic leukemia.^1,3

A 60-year-old renal transplant patient on triple drug immunosuppression presented with progressive neck swelling. Despite an uneventful posttransplant period with stable graft function, he developed chronic graft rejection and rising serum creatinine levels. Subsequent neck swelling revealed thyroid involvement by mucormycosis. Emergent tracheostomy was performed due to bilateral recurrent laryngeal nerve involvement and acute respiratory distress. Total thyroidectomy showed extensive necrotic tissue [Figure 1a] and histopathology confirmed angioinvasive mucormycosis [Figure 1b and 1c]. Fungal stains revealed positive findings [Figure 1d]. Despite the initiation of systemic antifungal therapy, the patient succumbed to the disease within 2 days.

Close

Figure 1:

(a) Intra-operative image showing necrotic avascular field. (b) Photomicrograph showing abundant broad aseptate branched fungal hyphae and spores with necrotic slough (HE 100×). (c) Photomicrograph showing extensive angio-invasion (HE 200×). (d) Photomicrograph showing Grocott Methamine Silver (GMS) positive fungal hyphae (HE 200×).

Export to PPT

Invasive fungal infections, particularly in renal transplant recipients, pose diagnostic and therapeutic challenges. While Candida infections are common, invasive aspergillosis is highly fatal. Aspergillus is among the most frequent fungal infections of the thyroid, while mucormycosis is comparatively less prevalent.^1,2 Mucormycosis involving the thyroid gland is rare and often diagnosed incidentally during postmortem examination.⁴ The thyroid’s resistance to infection is attributed to various factors, including its vascular supply, capsule and high iodine content. Diagnosing mucormycosis is difficult, often mimicking other thyroid conditions. Prompt treatment, including early recognition and surgical resection is crucial for better survival.^4,5 Despite efforts, mucormycosis mortality rates remain high, especially in cases of dissemination as seen in this patient.

This case underscores the need for swift diagnosis and aggressive treatment in isolated thyroid gland mucormycosis, a rare complication in transplant recipients under immunosuppressive therapy.