De novo purely prostatic large-cell neuroendocrine carcinoma with thyroid and adrenal metastases

Large-cell neuroendocrine carcinoma (LCNEC) is a rare neuroendocrine prostatic malignancy. It usually arises after androgen deprivation therapy (ADT), while de novo cases are even more infrequent, with only six cases described. The patient was a 78-year-old man with no history of ADT who presented with cervical lymphadenopathy. Diagnostic approaches included PET/CT, MRI, CT scans, ultrasonography, biopsies, and cytological and immunohistochemical evaluations. Results showed a poorly differentiated carcinoma in the thyroid gland accompanied by cervical lymph node enlargement. Thyroid surgery revealed LCNEC metastasis to the thyroid gland. Additional metastases were identified in both the adrenal glands. Despite appropriate treatment, the patient died of the disease. De novo LCNEC of the prostate is a rare, highly aggressive tumor with a poor prognosis. It is resistant to most therapeutic agents, has a high metastatic potential, and is usually diagnosed at an advanced stage. Further studies are required to characterize this tumor

Hypercalcemic Crisis Due to a Giant Intrathyroidal Parathyroid Adenoma, with Postsurgical Severe Hypocalcemia and Hungry Bone Syndrome: A Case Report

Background: Parathyroid adenoma is the most common cause of hypercalcemia and rarely leads to a hypercalcemic crisis, which is an unusual endocrine emergency that requires timely surgical excision. Case presentation: A 67-year-old male was admitted to the ER of the Euroclinic Hospital, Athens, Greece, because of elevated calcium levels and a palpable right-sided neck mass, which were accompanied by symptoms of nausea, drowsiness, and weakness for six months that increased prior to our evaluation. A gradual creatinine elevation and decreasing mental state were observed as well. The initial laboratory investigation identified severely elevated serum calcium (3.6 mmol/L) levels consistent with a hypercalcemic crisis (HC) and parathyroid hormone PTH (47.6 pmol/L) due to primary hyperparathyroidism. Neck ultrasonography (USG) identified a large, well-shaped cystic mass in the right thyroid lobe. With a serum calcium concentration of 19.5 mg/dL and a PTH of 225.3 pmol/L, the patient underwent partial parathyroidectomy and total thyroidectomy, which decreased serum calcium and PTH to 2.5 mmol/L and 1.93 pmol/L, respectively. Histology revealed a giant intrathyroidal cystic parathyroid adenoma, which was responsible for the hypercalcemic crisis. Postoperatively, the patient developed severe biochemical and clinical hypocalcemia, with calcium concentrations as low as 1.65 mmol/L, consistent with hungry bone syndrome (HBS), which was treated with high doses of intravenous calcium gluconate and oral alfacalcidol, and a slow recovery of serum calcium. After discharge, parathyroid function recovered, and symptomatology resolved entirely in more than one month. Discussion/conclusions: We present a case involving an exceptionally large intrathyroidal parathyroid adenoma that is characterized by clinical manifestations that mimic malignancy. The identification and treatment of such tumors is challenging and requires careful preoperative evaluation and postoperative care for the risk of hungry bone syndrome

Nationwide Real-World Data of Microsatellite Instability and/or Mismatch Repair Deficiency in Cancer: Prevalence and Testing Patterns

Determination of microsatellite instability (MSI)/mismatch repair (MMR) status in cancer has several clinical implications. Our aim was to integrate MSI/MMR status from patients tested in Greece to assess the prevalence of MSI-high (MSI-H)/deficient MMR (dMMR) per tumor type, testing patterns over time and concordance between MSI and MMR status. We retrospectively recorded MSI/MMR testing data of patients with diverse tumor types performed in pathology and molecular diagnostics laboratories across Greece. Overall, 18 of 22 pathology and/or molecular diagnostics laboratories accepted our invitation to participate. In the 18 laboratories located across the country, 7916 tumor samples were evaluated for MSI/MMR status. MSI/MMR testing significantly increased in patients with colorectal cancer (CRC) and other tumor types overtime (p < 0.05). The highest prevalence was reported in endometrial cancer (47 of 225 patients, 20.9%). MSI-H/dMMR was observed in most tumor types, even in low proportions. Among 904 tumors assessed both for MSI and MMR status, 21 had discordant results (overall discordance rate, 2.3%). We reported MSI-H/dMMR prevalence rates in patients with diverse cancers, while demonstrating increasing referral patterns from medical oncologists in the country overtime. The anticipated high rate of concordance between MSI and MMR status in paired analysis was confirmed