Pneumocystis pneumonia mimicking Lung metastasis in a HIV- Positive Patient with Metastatic Follicular Thyroid Cancer Dr ZM Jawa MBBS, MSc, FMCR, FCNP, FEBNM Senior Consultant/European Board Certified in Nuclear Medicine National Hospital Abuja NIGERIA

Case Mrs E.K 46yrs old female Known HIV on antiretroviral medication. Histological diagnosis of a follicular thyroid CA and had total thyroidectomy previously but did NOT have and post-thyroidectomy ablation with I-131 On 100mcg thyroxine.

Clinical Evaluation She was in severe respiratory, pale, acyanosed and well oriented. Chest; RR 32/min, SPO 78% Dull percussion Poor air entry bilaterally Coarse crepitation on both lung

Laboratory findings FBC, PCV 35%, lymphocytosis TFT; hypothyroid, TSH 13MIU/ML Thyroglobulin assay; 23IU/ml(0-4) CD4 COUNT; 310cell/mc

Radiological findings CXR; showed widespread multiple lung infiltration with multiple masses Thyroid USS; Residual thyroid tissue in the neck mainly on the right. No lymphadenopathy

Assessment Metastatic Follicular Thyroid CA with background HIV disease

Plan 1 Diagnostic whole body I-131 imaging Oral 5mCi I-131 Whole body acquired 3day after oral of I-131.

Pre-therapy whole body I-131

Assessment 2 Histologically confirmed follicular thyroid CA and HIV Disease Chest signs and symptoms and CXR features of mets, but NO uptake of I-131 I-131 avid lesions on the left iliac bone and proximal right femur. Dedifferentiation Co-existing Dual tumour

Plan 2 Lung biopsy

Pneumocystis Carinii Pneumonia

Treatment Oral co-trimaxazole 960mg daily X 14days Oral prednisolone 30mg daily(taped) Cont.. Antiretroviral medication.

Discussion The lung is a common site for metastasis from follicular thyroid cancer. Pneumocystis pneumonia is a fungal lung infection commonly seen in HIV-positive patients. The clinical presentation and radiological features of pneumocystis pneumonia and lung metastasis from follicular thyroid cancer are very similar and often indistinguishable, however, their management differs.

Pneumocystis pneumonia is treated with a simple course of antibiotics, while lung metastasis from follicular thyroid cancer requires high dose therapy with radioactive I-131.

In patients with metastatic follicular thyroid cancer that are HIV-positive presenting with lung infiltrations, it is important to make a proper diagnosis in order to institute appropriate and prompt treatment

Conclusion To our knowledge, this is the first documented case of a HIV-positive patient with metastatic follicular thyroid cancer presenting with pneumocystis pneumonia mimicking lung metastasis. The rarity of this case and the importance of creating awareness among clinician of the existence of this disease.

listen Thinking outside the ‘box’ Pre-therapy whole body I-131 scan

Thank you