De novo myeloid sarcoma mostly presented isolated. Lesions were often localized at skin and lymph nodes. Genetic aberrations frequently involved core-binding factor rearrangements in de novo cases and a complex karyotype in secondary cases.

In recent years, melanoma treatment has radically changed with the emergence of targeted therapies and immunotherapies. Both have led to improved survival for patients with advanced or unresectable melanoma. Targeted therapies with BRAF inhibitors in the lead use the presence of activating driver mutations to inhibit tumour growth. Forty to 60% of melanomas harbour BRAF mutations, which makes them susceptible to treatment with BRAF and/or MEK inhibitors. In parallel, the development of immunotherapeutic agents has also expanded. These agents stimulate the endogenous immune system of the patient to eradicate cancer cells. Immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed death 1 (PD-1) resulted in durable responses in a subset of patients. An important issue with immunotherapy lies in the identification of patients who will benefit from treatment. In this review, we will discuss these recent developments in melanoma therapy and highlight the role of the pathologist in both types of treatment.

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Background: The most frequent metastases to the thyroid originate in the kidney, lung or breast. Colorectal adenocarcinoma represents less than 4% of metastases to the thyroid gland. Solitary metastases of colorectal cancer with no other manifestation of disseminated cancer disease are exceedingly rare. Within the Bethesda Classification for Reporting ­Thyroid Cytopathology, metastases are included in Diagnostic Categories “Suspicious for Malignancy” and “Malignant.” Cases: We present 2 cases of colorectal adenocarcinoma metastatic to the thyroid gland, diagnosed by fine-needle aspiration (FNA). One metastasis occurred in normal thyroid parenchyma; the other was a tumour-to-tumour metastasis into a follicular carcinoma of the thyroid. The latter is the first published tumour-to-tumour metastasis of a colorectal carcinoma in the thyroid from which both components were diagnosed by FNA. Conclusion: Diagnosing a metastasis to the thyroid is challenging. On FNA, a dual cell population should raise suspicion. Immunocytochemical and molecular analysis may be helpful. Clinical information is essential in guiding specific ancillary technique panels in scant cellular material.