Some uncommon cystic lesions in the anterior head and neck region: Pitfalls to be avoided on cytology.

Cystic lesions of the anterior head and neck region are a challenging and frequent finding on cytological smears. The scant amount of cellular material in cystic slides poses the greatest difficulty to interpretation, so that frequently they are diagnosed as inadequate or with minimal cellular component. Despite the majority of cystic lesions being benign, a minor portion consist of malignant cystic entities. In these latter cases, the evidence of very scant malignant cells can be misdiagnosed and/or underestimated, leading to a false negative diagnosis. Many papers have already described and detailed the range of possible benign and malignant cystic lesions in head and neck. In the current review we have focused on the less common entities that often lead to serious misinterpretation.

Cystic lesions in the salivary gland. Pitfalls to be avoided on cytology.

Cystic lesions of the salivary glands are very uncommon entities. However, on occasion, some neoplasms of the salivary glands show a cystic component, which may be predominant or only partially cystic. Basal cell adenoma, canalicular adenoma, oncocytoma, sebaceous adenoma, intraductal papilloma, epithelial-myoepithelial carcinoma, intraductal carcinoma, and secretory carcinoma are such cystic entities. Cystic degeneration and necrosis, which can develop within solid tumours, represent another possibility. The ability to recognise this type of lesion is a challenge in diagnostic cytology because hypocellular fluid is frequently recovered. Furthermore, evaluating all of the differential diagnoses for cystic lesions of the salivary glands is helpful in obtaining the correct diagnosis. Herein, we evaluate the various types of cystic lesions within the salivary glands.

Neuroendocrine neoplasms of the breast: a review of literature.

Primary neuroendocrine neoplasms (NENs) of the breast are characterized by neuroendocrine architectural and cytological features, which must be supported by immunohistochemical positivity for neuroendocrine markers (such as Chromogranin and Synaptophysin). According to the literature, making a diagnosis of primary neuroendocrine breast cancer always needs to rule out a possible primary neuroendocrine neoplasm from another site. Currently, the latest 2022 version of the WHO of endocrine and neuroendocrine neoplasms has classified breast NENs as well-differentiated neuroendocrine tumours (NETs) and aggressive neuroendocrine carcinomas (NECs), differentiating them from invasive breast cancers of no special type (IBCs-NST). with neuroendocrine features. The current review article describes six cases from our series and a comprehensive review of the literature in the field of NENs of the breast.

What Can Trigger Spontaneous Regression of Breast Cancer?

BACKGROUND: Spontaneous regression of tumors is a rare phenomenon in which cancer volume is reduced or, alternatively, a tumor completely disappears in the absence of any pharmacological treatment. This phenomenon has previously been described in several tumors, such as neuroblastomas, testicular malignancies, renal cell carcinomas, melanomas, and lymphomas. Spontaneous remission has also been documented in breast cancer; however, it represents an extremely rare and poorly understood phenomenon, with only a few reported cases in the literature. METHODS: We herein report two cases of breast cancer that showed spontaneous tumor regression in the surgical specimen after a pathologically confirmed diagnosis of invasive breast cancer in core needle biopsy samples. RESULTS: Macroscopically, both the surgical samples revealed a whitish, fibrous area with a rubbery consistency. On histological examination, diffuse fibrous tissue, hemosiderin deposition, and chronic inflammation were observed. The first case showed the complete disappearance of the tumor, whereas the second case showed just a small (3 mm), residual nest of neoplastic cells. CONCLUSIONS: Although spontaneous regression of breast cancer is a rare event, it is important to know that it might happen. It is also of great importance to try to better explain, over time, its underlying mechanism. This knowledge could help us to further develop cancer prevention methods and predict the clinical course of these kinds of neoplasms.

Diagnostic role of FNA cytology in the evaluation of cervical lymph nodes in thyroid cancers: Combined evaluation of thyroglobulin in eluate from FNA cytology.

BACKGROUND: The presurgical evaluation of cervical lymph nodes (CLNs) in the management of thyroid malignant lesions is crucial for the extent of surgery or detection of metastases. In these last decades, fine-needle aspiration cytology (FNAC) has been shown to have a central role in the detection of nodal thyroid metastases. It is adopted for the possibility of confirming suspected metastases either in the presurgical phase or in the follow-up of patients after thyroidectomy. However, FNAC from CLNs can be challenging, especially in cystic lesions. In this regard, the combination of FNAC with thyroglobulin measurement in the eluate from FNAC (Tg-FNAC) seems to increase the sensitivity of FNAC in the detection of CLN metastases. The role of FNAC and Tg-FNAC was investigated in this series. METHODS: One hundred fifty-three prospective cytological samples of CLNs were studied along with surgical follow-up in the period between 2020 and 2022. Immunocytochemistry (ICC) was performed on liquid-based cytology-stored material. RESULTS: One hundred fifty-nine enlarged CLNs included 19 central lymph nodes and 140 CLNs. Forty-two thyroidal CLN metastases and 117 reactive lymph nodes were found. Thirty-one CLN dissections were performed in patients with a previous diagnosis of thyroid carcinoma (mostly papillary thyroid carcinoma [PTC]), whereas 128 CLNs with a concomitant suspicious and/or malignant thyroid nodule were found. There was one false-positive case among all the malignant histologically confirmed cases, and two of 117 reactive CLNs (1.7%) had a diagnosis of metastatic PTC. Markedly high Tg-FNAC was found in all metastatic CLNs, including 11 cystic metastatic CLNs detected by Tg-FNAC with a negative FNAC. ICC (including Tg, CK-19, and LCA) recognized nine cases with low Tg-FNAC and scant suspicious thyrocytes. Tg-FNAC plus FNAC diagnosed 94.2% of malignancies. CONCLUSIONS: FNAC represents a valid method for the evaluation of CLNs, especially combined with ICC. Tg-FNAC is an additional method with a useful role in FNAC.

Endometrial carcinomas with dyshesive, eosinophilic, and vacuolated (histiocyte-like) tumor cells: a reactive-like phenotype associated with aggressive behavior.

Herein, we present a clinicopathological and molecular analysis of four cases of endometrial carcinoma (EC) diffusely exhibiting dyshesive cells with wide eosinophilic and vacuolated cytoplasm (histiocyte-like tumor cells, HLTCs). We compared these HLTCs to similar cells found in microcystic, elongated and fragmented (MELF) pattern (n = 20) or after neoadjuvant chemotherapy (NAC) (n = 5). The four cases were endometrioid, serous, clear cell, and gastric-type; all were at FIGO stage ≥ III. HLTCs showed an epithelial Müllerian phenotype and at least focal CK20, HNF1ß, and CK5/6 expression, with aberrant e-cadherin and ß-catenin expression; two cases were MMR-deficient, and one was p53-abnormal; all were POLE wild type. MELF-associated and NAC-associated HLTCs showed similar morphological/immunophenotypical features. However, MELF-associated HLTCs were mainly intraglandular and inflammation-associated, did not form a distinct tumor component, and showed no relationship with lymph node metastases. In conclusion, different histotypes of EC may show a prominent HLTC component, which shows peculiar morphological/immunophenotypical features and appears associated with aggressive behavior.