RESUMO
BACKGROUND: A secondary lesion in the thyroid gland is a rare clinical scenario diagnosed preoperatively during the evaluation of a neck mass, postoperatively in a thyroidectomy specimen or in autopsy studies. Even though the thyroid gland is highly vascular, secondary malignant lesions are rare accounting for 0.2% of all thyroid malignancies. Thyroid gland secondary lesions are often metachronous in presentation as they are seldom evaluated in the initial diagnostic workup of the primary lesion. Fine-needle aspiration cytology (FNAC) is a useful modality for the diagnosis of secondary thyroid lesions. MATERIALS AND METHODS: A 6-year retrospective review (2016-2021) was carried out to assess the secondary lesions in the thyroid gland. Papanicolaou and field-stained FNAC smears of secondary thyroid lesions were reviewed. Ancillary techniques were performed on the cell block for differentiating from the primary thyroid gland lesions. RESULTS: There were 383 patients in our archives. There were only 18 cases (4.7%) that presented with secondary neoplastic lesions in the thyroid gland either by direct extension, metastases or as a hematolymphoid malignancy. There were 14 (77.7%) cases that presented with non-hematolymphoid secondary lesions while 4 (22.3%) cases presented with hematolymphoid malignancies. Thyroid secondaries were predominantly seen in female patients (female: male ratio of 1.5:1). Most of the cases presented with a synchronous secondary lesion (n = 14, 77.7%) and few metachronous secondary lesions were also noted (n = 4, 22.3%). CONCLUSION: Although exceedingly rare, the detection of secondary thyroid gland lesions is important for staging and planning treatment.
RESUMO
A 42-year-old male patient with high-risk prostate adenocarcinoma underwent baseline 99m Tc-methylene diphosphonate skeletal scintigraphy, which revealed two skeletal metastases and an area of faint radiotracer uptake in the left femoral shaft. In view of oligo-metastatic nature of the disease in the bone scan and the young age of the patient, he was a candidate for metastases-directed treatment. Single photon emission computed tomography (SPECT)/CT was performed to further characterize this lesion. It was revealed to be a small soft tissue density lesion within the fatty bone marrow density, suggesting bone marrow involvement. A more sensitive evaluation of such areas with faint radiotracer uptake may be needed in high-risk prostate cancer patients where access to advanced modalities is limited. Their significance will also need reassessment as their detection will improve with technological advancements.
RESUMO
A 60-year-old male, a diagnosed case of squamous cell carcinoma of the hypopharynx, underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for response assessment. PET/CT revealed mildly increased 18F-FDG uptake and contrast enhancement in the region of the primary, which was suggestive of postradiation changes. Interestingly, a benign-looking cyst was seen in the shrunken, poorly-functioning left kidney, with mildly elevated 18F-FDG uptake. Structurally, the lesion appeared benign on ultrasound and sequential CT images. However, 18F-FDG was the only feature which alluded to the possibility of another pathology like low-grade malignancy or oncocytoma. The lesion was biopsied, which revealed Clear-Cell International Society of Urologic Pathologists grade-1 renal cell carcinoma. Consequently, the patient was posted for surgery.
