Case of lung fine needle aspiration showing mucinous cells and extracellular mucin.

Mucinous neoplasm with extracellular mucin can be challenging to interpret on fine needle aspiration and core biopsies. Determining the biologic origin of the mucin/mucinous cells, that is, benign/incidental versus neoplasm, invasive versus in situ, and primary versus metastatic tumors, requires a thorough multidisciplinary evaluation. The work up of these lesions includes morphologic analysis with ancillary immunohistochemical and/or molecular studies and correlation with clinical and imaging studies. This review outlines a practical approach to the diagnosis of mucinous lesions in the lung with comprehensive review of literature.

Diagnostic implication of extracellular mucin in pancreatic/biliary brushing and stent cytology.

BACKGROUND: Pancreatic and/or biliary (PB) brushing is commonly used to rule out malignant strictures. Many studies have attempted to characterize cytomorphologic characteristics of brushing and stent cytology. However, scant literature exists on the diagnostic implication (DI) of thick extracellular mucin (ECM) indicative of neoplasm in these samples. This study was aimed at reviewing the DI of thick ECM in PB brushing and stent cytology. METHODS: A retrospective search of consecutive cytologic samples of PB brushings/stents with corresponding surgical pathology or relevant clinical information over a 1-year period was performed. Blinded review of the slides was performed by two cytopathologists. The slides were assessed for the presence, quantity, and quality of ECM. The results were analyzed for statistical significance with the Fisher exact and χ2 tests. RESULTS: One hundred ten cases were identified from 63 patients. Twenty-two cases (20%) were PB brushings only without a prior stent. The remaining 88 cases (80%) had a preexisting stent for symptomatic obstruction. Fourteen of 22 cases (63%) without prior stents and 67 of 88 poststented cases (76%) were nonneoplastic (NN) upon follow-up. ECM was present more frequently in neoplastic cases than in NN cases (p = .03). Among NN cases (n = 87), poststented samples showed more evidence of ECM than prestented samples (15% vs. 45%, p = .045). Identical thick ECM was observed in NN poststent and main-duct intraductal papillary neoplasm samples. CONCLUSIONS: Although ECM was frequently seen in neoplastic cases, NN cases showed increased evidence of thick ECM among poststented samples. Thick ECM may be common in stent cytology, regardless of the underlying biologic process.

Diagnostically Challenging Subtypes of Invasive Lobular Carcinomas: How to Avoid Potential Diagnostic Pitfalls.

Invasive lobular carcinoma is the most common special breast carcinoma subtype, with unique morphological (discohesive cells, single-cell files, targetoid pattern) and immunohistochemical (loss of E-cadherin and ß-catenin staining) features. Moreover, ILC displays a poor response to neoadjuvant therapy, a different metastatic pattern compared to invasive breast carcinoma of no special type, as well as unique molecular characteristics. In addition to the classic variant of invasive lobular carcinoma, several other well-recognized variants exist, including classic, alveolar, tubulolobular, solid, pleomorphic, signet-ring, and mixed. Furthermore, three novel variants of invasive lobular carcinoma, i.e., with extracellular mucin production, papillary features, and tubular elements, have been described during the last decade. We herewith focus on the unique morphological and immunohistochemical characteristics of these novel varieties of invasive lobular carcinoma, as well as differential diagnostic considerations and potential diagnostic pitfalls, especially when dealing with biopsy specimens.

Bilateral Ovarian Juvenile Granulosa Cell Tumor with Extensive Extracellular Mucin Deposition in an Adolescent: Report of a Rare Presentation with a Comprehensive Review of the Literature.

Juvenile granulosa cell tumor (JGCT) of the ovary is an uncommon malignancy, with most cases seen in adolescent girls and young women. The majority of these patients present with unilateral ovarian disease, and to date, bilateral JGCTs have been reported in 10 cases. Although the histopathologic features have been detailed in the published literature, extensive extracellular mucin deposition has been documented in only one case. Herein, we report a 17-year-old adolescent girl with bilateral solid-cystic adnexal masses diagnosed as bilateral JGCT with abundant extracellular mucin deposition on histopathology. The index case highlights a rare clinical and histopathologic presentation of JGCT. Adequate knowledge of such unusual presentations is essential for accurate distinction from other ovarian tumors and appropriate management.

Clinicopathological Study of Mucinous Carcinoma of Breast with Emphasis on Cytological Features: A Study at Tertiary Care Teaching Hospital of South India.

Introduction Mucinous carcinoma (MC) is a rare form of breast cancer. It accounts for 1 to 7% of the cases and characterized by the presence of extracellular mucin (ECM). Depending on the amount of mucin, it is classified into pure mucinous carcinoma (> 90%, PMC) and mixed mucinous carcinoma (MMC; < 90%). In comparison to most common subtypes, MC is having better prognosis. There exist clinicopathological differences among PMC and MMC and also MC and IDC-NOS. Materials and Methods MCs diagnosed between January 2012 and December 2017 were included. Fine needle aspiration cytology smears were screened for cellularity, ECM, nuclear pleomorphism, signet ring cells (SRC), mucinophages, and myxovascular fragments (MVF). Histopathology slides were screened to confirm the diagnosis. Immunohistochemistry slides were graded as per the standard protocol. Statistical analyses were performed by SPSS software. Results In the present study, MC constituted 3.3%. The mean age of the patients was 50.9 years. ECM, mucinophages, and SRC were the key diagnostic cytological features. The PMC and MMC were clinicopathologically distinct with respect to gross findings and lymph node status. MMCs were highly proliferative. The mean duration of follow-up was 24.5 months. Complications were more common in MMC than PMC. Lymph node involvement is the key prognostic factor and it is independent of other prognostic factors like age, size, and hormonal receptor status. Conclusion PMC are rare subtype of breast cancer. The diagnostic cytological features are ECM, MVF, and SRC. MMC and PMC are clinicopathologically and genetically distinct.

A review of mucinous lesions of the breast.

Mucinous lesions of the breast include a variety of benign and malignant epithelial processes that display intracytoplasmic or extracellular mucin, including mucocele-like lesions, mucinous carcinoma, solid papillary carcinoma, and other rare subtypes of mucin-producing carcinoma. The finding of free-floating or stromal mucin accumulations is a diagnostic challenge of which the significance depends on the clinical, radiologic, and pathologic context. This article emphasizes the differential diagnosis between benign and malignant mucin-producing lesions, with a brief consideration of potential mimics, such as biphasic and mesenchymal lesions with associated with mucinous, myxoid, or matrix material.

Invasive Lobular Carcinoma with Extracellular Mucin Production: Description of a Case and Review of the Literature.

Invasive lobular carcinoma of the breast is the second most common subtype of breast carcinoma. It accounts for 5-15% of the breast carcinoma cases reported. It shows a different metastatic pattern compared to invasive carcinoma of no special type. There are several variants of this cancer including the classic, solid, signet ring cell, tubulolobular, alveolar, trabecular, pleomorphic, and mixed subtypes each one with a distinctive morphology. Invasive lobular carcinoma has been associated with intracellular mucin production, in the form of intracytoplasmic lumina and signet ring cells whereas extracellular mucin production has been related to carcinomas of ductal origin. A new variant that displays extracellular mucin production was described recently. Only nineteen cases of this rare entity have been reported to date. In this manuscript, we report an additional case of invasive lobular carcinoma with extracellular mucin production, describing its clinico-pathological characteristics, and review the literature on the same.

[Invasive breast lobular carcinoma with extracellular mucin: a clinicopathological analysis].

Objective: To study the clinicopathological features of invasive lobular carcinoma (ILC) of the breast with extracellular mucin and outcomes of patients. Method: Clinicopathological features and clinical follow-up (39-123 months and a median follow-up of 55 months) of seven ILC with extracellular mucin were obtained. Hematoxylin-and-eosin (H&E) and immunohistochemistry (IHC) stained sections were reviewed, and fluorescence in situ hybridization (FISH) assay was performed for tumors with HER2 IHC 2+. Patient prognosis was analyzed and literatures related to ILC with extracellular mucin were reviewed. Results: All seven patients were female, aged from 43 to 73 years (median age, 55 years). The tumors ranged in size from 1 to 5 cm (median size 2 cm). All seven cases were of histological grade 2. Most areas of the tumors presented with the morphology of classic ILC, and variable amount of extracellular mucin were observed focally. In six cases, part of the tumor cells contained intracellular mucin, and the nucleus were pushed to one side of the cells, creating the impression of signet-ring cells. Two patients had lymph node metastases at diagnosis, and developed liver and bone metastases at 38th and 48th month, respectively, after surgery, and died at 48th and 123th month, respectively. While the other five patients, except one lost to follow-up, had been disease-free during the follow-up period. IHC results showed estrogen receptor (ER) and progesterone receptor (PR) positivity in 7/7 and 6/7 cases, respectively. Tumors of six patients were HER2 IHC 0/1+. The remaining one was HER2 IHC 2+, while FISH assay revealed HER2 gene amplification in that tumor. The proportion of cases with HER2-positivity was 1/7. The proliferation index Ki-67 ranged from less than 5% to 30%, and Ki-67 less than or equal to 10% were in 5/7 cases. According to the 2013 St. Gallen International Expert Consensus on breast cancer, all tumors were of luminal types; of those, two were luminal A and five were luminal B. Conclusions: ILC with extracellular mucin tends to occur in women over 50 years old. All tumors in the study are grade 2 classic ILC, with signet-ring cells as a common feature. All seven tumors are classified as luminal types, with luminal B as the main molecular subtype.

Invasive breast lobular carcinoma with extracellular mucin: a clinicopathological analysis / 中华病理学杂志

Objective@#To study the clinicopathological features of invasive lobular carcinoma (ILC) of the breast with extracellular mucin and outcomes of patients.@*Method@#Clinicopathological features and clinical follow-up (39-123 months and a median follow-up of 55 months) of seven ILC with extracellular mucin were obtained. Hematoxylin-and-eosin (H&E) and immunohistochemistry (IHC) stained sections were reviewed, and fluorescence in situ hybridization (FISH) assay was performed for tumors with HER2 IHC 2+. Patient prognosis was analyzed and literatures related to ILC with extracellular mucin were reviewed.@*Results@#All seven patients were female, aged from 43 to 73 years (median age, 55 years). The tumors ranged in size from 1 to 5 cm (median size 2 cm). All seven cases were of histological grade 2. Most areas of the tumors presented with the morphology of classic ILC, and variable amount of extracellular mucin were observed focally. In six cases, part of the tumor cells contained intracellular mucin, and the nucleus were pushed to one side of the cells, creating the impression of signet-ring cells. Two patients had lymph node metastases at diagnosis, and developed liver and bone metastases at 38th and 48th month, respectively, after surgery, and died at 48th and 123th month, respectively. While the other five patients, except one lost to follow-up, had been disease-free during the follow-up period. IHC results showed estrogen receptor (ER) and progesterone receptor (PR) positivity in 7/7 and 6/7 cases, respectively. Tumors of six patients were HER2 IHC 0/1+. The remaining one was HER2 IHC 2+, while FISH assay revealed HER2 gene amplification in that tumor. The proportion of cases with HER2-positivity was 1/7. The proliferation index Ki-67 ranged from less than 5% to 30%, and Ki-67 less than or equal to 10% were in 5/7 cases. According to the 2013 St. Gallen International Expert Consensus on breast cancer, all tumors were of luminal types; of those, two were luminal A and five were luminal B.@*Conclusions@#ILC with extracellular mucin tends to occur in women over 50 years old. All tumors in the study are grade 2 classic ILC, with signet-ring cells as a common feature. All seven tumors are classified as luminal types, with luminal B as the main molecular subtype.

Invasive lobular carcinoma with extracellular mucin production-a novel pattern of lobular carcinomas of the breast. Clinico-pathological description of eight cases.

Invasive lobular carcinoma of the breast is known to produce intracellular mucin and has been recognized in single-case reports to show extracellular mucin production, as well. This latter morphology is not only rare but must also be under- or misdiagnosed. The aim was to better characterize this entity. Cases of lobular cancers demonstrating extracellular mucin formation were identified in a multi-institutional effort and their clinical and morphologic features were assessed. Immunohistochemistry was used to characterize the E-cadherin-membrane complex, neuroendocrine differentiation, and to some extent, mucin formation. All but one of the eight cases occurred in postmenopausal patients. Extracellular mucin production was present in 5 to 50% of the tumour samples and rarely also appeared in nodal and distant metastases. The tumours were completely E-cadherin negative and showed cytoplasmic p120 positivity. The majority (n = 6/8) was also completely negative for ß-catenin, but two tumours displayed focal ß-catenin positivity in the mucinous area. MUC1 and MUC2 expression was observed in all and 7/8 tumours, respectively; neuroendocrine differentiation was present in only one. Invasive lobular carcinoma with extracellular mucin formation is a rare morphologic variant of lobular carcinoma prone to be misdiagnosed and warranting further studies.