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.

Metastases to the parotid glands: An institutional experience.

BACKGROUND: Metastatic lesions to the salivary gland are rare and mostly affect the parotids. Metastases represent 8% of all malignant lesions of the parotid gland. Around 80% originate from squamous cell carcinomas (SCC) of the head and neck region. Fine needle aspiration (FNA) plays a crucial role in distinguishing primary salivary gland lesions from metastases. Herein we describe our series of metastases to the parotid glands. MATERIALS AND METHODS: We analysed 630 parotid gland FNAs over a decade including conventional and liquid-based cytology specimens. Ancillary techniques such as immunocytochemistry (ICC) were conducted on cell blocks. RESULTS: Eighty (12.4%) cases were malignant lesions, of which 53 (63.75%) were metastases including 24% melanoma, 22.6% SCC, 19% renal carcinomas, 7.5% breast carcinomas, 11.3% lung, 9% intestinal and 1.8% testicular, malignant solitary fibrous tumour and Merkel cell carcinoma. The 53 cases, classified according to the Milan system for salivary cytopathology, belonged to 5 Suspicious for malignancy (SFM) and 48 malignant (M) categories. Forty had a known history of primary malignancy (75.4%), while 13 were suspicious to be a metastatic localisation (24.5%), distributed as 5SFM (2SCC and 3Melanoma) and 8 M. A combination of clinical history, cytomorphology and ICC identified 100% of them. CONCLUSIONS: Fine needle aspiration plays a central role in the diagnostic workup of patients with metastatic lesions to their parotid glands, thereby defining the correct management. Diagnostic accuracy may be enhanced by applying ICC. Although melanoma and SCC are the most common histological types, several other malignancies may also metastasize to the parotid glands and should be kept into consideration.

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.

Updates from Our Institutional Experience with Thyroid Nodules Diagnosed as Metastases.

BACKGROUND: Thyroid metastases (TMs) are a rare entity, ranging between 0 and 24% in the autopsy series. In the assessment of the best management, the discrimination between a primary and a metastatic thyroid lesion is crucial. In this regard, fine needle aspiration cytology (FNAC) is likely to play a crucial role especially when ancillary techniques (i.e., immunocytochemistry (ICC) and molecular testing) are carried out. METHODS: We searched for all the TMs diagnosed using FNAC and analyzed between 2014 and 2023. The cases were processed with liquid-based (LBC) and ICC and molecular testing performed on LBC-stored material. RESULTS: We reported 2.2% (19 cases) of TMs out of 1022 malignancies. TMs included: 1 larynx carcinoma (LX-Ca), 1 melanoma, 2 breast carcinomas (B-Ca), 3 lung carcinomas (LG-Ca), 4 gastro-intestinal carcinomas (GI-Ca), and 8 clear cell renal carcinomas (CCRC). All patients had a previous cancer history, between 300 and 2 months from the primary cancers. The morphological features were supported by ICC, which were contributive in 100% of cases. All TMs cases were characterized by multiple thyroid nodules except the melanoma case. Four cases underwent total thyroidectomy (1 B, 1 LX, 1 melanoma, and 1 CCRC) whilst 15 TMs were treated with radio-chemotherapy. CONCLUSIONS: FNAC empowered the diagnostic workup of patients with TMs avoiding useless surgery. The low sensitivity of cytology might be reinforced by the application of ancillary techniques. We found a predominant rate of kidney metastatic carcinomas, followed by lung and breast. TMs are frequently multifocal and in a context of a systemic disease so a tailored therapy seems to be the best treatment.

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.

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.

Primary Mucinous Cystadenocarcinoma of the Breast Intermixed with Pleomorphic Invasive Lobular Carcinoma: The First Report of This Rare Association.

Primary mucinous cystadenocarcinoma (MCA) is a rare breast carcinoma subtype showing overlapping histopathological features with mucinous cystadenocarcinoma of the ovary and pancreas. Current literature data suggest a favorable prognosis of breast MCAs despite its immunoprofile usually revealing lack of expression of estrogen receptor, progesterone receptor and HER-2 and high Ki67. As far as we know, only 36 cases have been reported in the literature to date. Its ambiguous morpho-phenotypic profile makes histological diagnosis very challenging. It must be distinguished from typical mucin-producing breast carcinomas and, above all, metastases from the same histotype in other sites (ovary, pancreas, appendix). Herein, we report the case of a primary breast MCA occurring in a 41-year-old female with peculiar histological features.