Bilateral intra-lymph node Warthin's tumor as a potential diagnostic pitfall mimicking metastatic carcinoma

Warthin's tumor (WT) is a benign and frequent salivary gland tumor primarily affecting the parotid gland. In some cases, this tumor can involve the extra parotid region and affect cervical lymph nodes. Fine-needle aspiration can be the first step in the diagnostic approach to lymphadenopathy; however, specimens from intra-nodal WT can present a potential pitfall, leading to a misdiagnosis of metastasis. Here, we report an unusual case of a patient with bilateral WT in parotid lymph nodes misdiagnosed as metastases. In addition, we highlight the cytopathological aspects of WT to alert cytopathologists about this challenging diagnosis.

In situ melanoma of oral cavity: Diagnosis and treatment of a rare entity

Oral melanoma is an extremely aggressive and rare tumor. Commonly, oral melanomas are diagnosed as invasive tumors, which considerably reduces the chances of cure. In situ oral melanomas being exceedingly rare, which makes its clinicopathological and prognostic characteristics poorly known. Herein, we report a case of 67-year-old non-white woman with a large black patch on the maxillary alveolar mucosa. A biopsy was made and microscopical analysis revealed moderate atypical junctional melanocytic. Tumor cells were positive for S100 (Polyclonal), Melan-A (Clone A103) and Melanosome (HMB-45). The diagnosis of in situ oral melanoma was made and the patient was treated surgically with partial maxillectomy and rehabilitated with obturator prosthesis. Although extremely rare in situ melanomas should be considered in the differential diagnosis of non-invasive pigmented lesions of the oral mucosa.

Multifocal papillary carcinoma of the thyroid with heterotopic ossification and extramedullary hematopoiesis associated with a lipomatous follicular nodule

Heterotopic ossification has been described in papillary thyroid carcinoma in association with high incidence of extrathyroidal invasion, multifocality, lymph node metastasis, and older age. Nevertheless, it has not been described as a specific subtype of papillary thyroid carcinoma, because of its rarity. We described the case of an 80-year-old female patient, with familial history of papillary thyroid carcinoma. In the annual screening examination, she was diagnosed with thyroid nodules. The patient was submitted to a thyroidectomy because the fine needle aspiration cytology was positive for malignancy according to the Bethesda classification. The surgical specimen analyses showed a multifocal papillary carcinoma with one major lesion in the left lobe measuring 0.9 cm, and two small lesions (0.4 cm and 0.2 cm) in the right lobe. Only the biggest lesion in the right lobe had the osteoid matrix with rare osteoclasts and fat metaplasia with progenitor cells. There was perineural invasion, but vascular invasion was not identified. The margins were free and there was no extrathyroidal extension. In the left lobe there was an oncocytic nodule and a lipomatous follicular nodule. In recent years there has been a significant increase in the diagnosis of thyroid cancer, mainly because of the finding of microcarcinomas as a result of many requests for cervical image exams. Future studies may define (i) whether papillary thyroid carcinoma with heterotopic ossification is a true histological variant; (ii) the causes of that alteration; and (iii) eventual follow-up implications.