Tubular Growth Pattern Research Articles

The Great Mimicker: Goblet Cell Adenocarcinoma of the Appendix Mimicking Mammary Carcinoma in a Patient with a History of Metastatic Breast Cancer

Abstract Introduction/Objective Goblet cell adenocarcinoma of the appendix is a rare and aggressive malignancy with high- grade histological patterns that pose diagnostic challenges due to their resemblance to other tumors. Previous reports have indicated that high-grade goblet cell adenocarcinoma may exhibit similarities to well-differentiated neuroendocrine tumors, and metastatic high-grade goblet cell adenocarcinoma can manifest diverse histologic growth patterns within a single section. Methods/Case Report We present a case of an 82-year-old female with a known history of breast cancer with sacral metastasis, presenting with a left upper quadrant “pinching” sensation. Histopathological examination following colectomy showed features of metastatic mammary carcinoma with mixed lobular (pleomorphic and partial signet ring cell type) and ductal features (Figure 1); Notably, different histologic patterns were observed in two tumor deposits, highlighting the complexity of the diagnosis (Figure 2). However, further investigation of the tip of the appendix revealed goblet-like mucinous cells arranged in a tubular growth pattern (Figure 3). Immunohistochemical stains were performed with adequate controls, revealing positive staining for CK20, SATB2, and CDX2, while showing negativity for BRST2, SATB2, GATA3, CK7, PR, ER, and HER2 (Figure 4). These findings corroborate the diagnosis of goblet cell adenocarcinoma. Results (if a Case Study enter NA) NA Conclusion In our case, we observed morphological features of goblet cell adenocarcinoma that overlapped with those of established mammary carcinomas. This scenario underscores the diagnostic challenges posed by rare tumors and emphasizes the significance of identifying the low-grade component of goblet cell adenocarcinoma, particularly in patients with a history of metastatic breast cancer.

Fumarate hydratase–deficient renal cell carcinoma: A single institution–based study of 29 patients by clinicopathological, immunohistochemical and genetic approaches

Fumarate hydratase (FH)-deficient renal cell carcinoma (RCC) is a renal neoplasm associated with FH loss, aggressive behaviour, and poor survival. We present a histopathological and immunohistochemical overview of FH-deficient RCC to infer significant features for its differential diagnosis. In this study, FH-deficient RCC tissue samples from patients who underwent surgical resection or biopsy at a single institution between July 1995 and August 2022 were reviewed by conventional haematoxylin and eosin staining, immunohistochemistry, and whole-genome analyses. Twenty-nine FH-deficient RCC specimens were examined ​based on immunohistochemistry findings regarding FH and S-(2-succino)cysteine (2SC). The histopathological findings included conspicuous nucleoli with a perinucleolar halo, resembling viral inclusion, eosinophilic cytoplasm, papillary and tubular growth patterns, and lack of stromal foam cell collection. Some tumours showed desmoplastic stroma, tumour-infiltrating lymphocytes, and solid growth pattern. One tumour presented low-grade oncocyte-like histomorphology. Widespread negativity for CD10, keratin 7, keratin 20, anaplastic lymphoma kinase, and GATA3 were observed in 24 specimens. All samples were positive for paired box gene 8, and the level of alpha-methylacyl-CoA racemase expression was variable. Whole-exome sequencing of 19 tumours revealed nonsynonymous mutations, including missense mutations, splice donors, splice acceptors, frameshifts, and deletions in 15 tumours. Eleven tumours showed novel mutations. In conclusion, results revealed generally unfavourable clinical presentations and outcomes with diverse variants of FH mutation. These findings, along with the histopathological and immunohistochemical features, can be used to guide diagnosis and treatment.

Adenomatoid tumor with extensive reactive smooth muscle: a diagnostic dilemma

Abstract Introduction/Objective Adenomatoid tumors are slow-growing benign tumors of mesothelial origin. They comprise 30% of all tumors of the paratesticular area. In this location, they commonly involve the epididymis, spermatic cord, ejaculatory duct and rarely testicular parenchyma. Histologically, a spectrum of growth patterns can be seen, such as adenoid, tubular, glandular, solid, or cystic. In some cases, a smooth muscle component can also be present. The purpose of this report is to describe a case of adenomatoid tumor with exuberant smooth muscle component, mimicking leiomyoma. Methods/Case Report A 28-year-old male presented with painless left inguinal bulge. He noticed it five years prior, and it had been slowly growing since then. Examination revealed a paratesticular mass which was subsequently excised. Grossly, the tumor was firm with smooth, white-tan cut surfaces. Microscopically, the tumor was well- circumscribed, showing predominance of smooth muscle bundles and rare cuboidal to ovoid cells in tubular growth pattern. In the background there was little intervening stroma. Immunohistochemical stains showed the cuboidal cells to be positive for WT1 and calretinin, confirming the mesothelial origin. Diagnosis of adenomatoid tumor was rendered. In contrast to adenomatoid tumors, leiomyomas are whiter and firmer on gross examination and lack the characteristic tubules or cystic spaces lined by mesothelial cells. Results (if a Case Study enter NA) N/A Conclusion Exuberant smooth muscle differentiation in adenomatoid tumor can mislead to diagnosis of leiomyoma. Careful inspection for tubules of mesothelial origin and appropriate immunohistochemical stains are key to accurate diagnosis. Pathologists need to be aware of this potential pitfall.

Identification of MicroRNA Expression Profiles Related to the Aggressiveness of Salivary Gland Adenoid Cystic Carcinomas.

Adenoid cystic carcinoma (ACC) has been reported as the second most common carcinoma of the salivary glands. Few studies have associated miRNA expression with ACC aggressiveness. In this study, we evaluated the miRNA profile of formalin-fixed, paraffin-embedded (FFPE) samples of salivary gland ACC patients using the NanoString platform. We studied the miRNA expression levels associated with the solid growth pattern, the more aggressive histologic feature of ACCs, compared with the tubular and cribriform growth patterns. Moreover, the perineural invasion status, a common clinicopathological feature of the disease that is frequently associated with the clinical progression of ACC, was investigated. The miRNAs showing significant differences between the study groups were selected for target prediction and functional enrichment, which included associations with the disease according to dedicated databases. We observed decreased expression of miR-181d, miR-23b, miR-455, miR-154-5p, and miR-409 in the solid growth pattern compared with tubular and cribriform growth patterns. In contrast, miR-29c, miR-140, miR-195, miR-24, miR-143, and miR-21 were overexpressed in patients with perineural invasion. Several target genes of the miRNAs identified have been associated with molecular processes involved in cell proliferation, apoptosis, and tumor progression. Together, these findings allowed the characterization of miRNAs potentially associated with aggressiveness in salivary gland adenoid cystic carcinoma. Our results highlight important new miRNA expression profiles involved in ACC carcinogenesis that could be associated with the aggressive behavior of this tumor type.

The Histopathological Characteristic of Gastric Carcinoma in the Belgian Tervueren and Groenendael Dog: A Comparison of Two Classification Methods.

Gastric carcinoma is generally considered to be a rare disease in dogs, carrying a grave prognosis. However, in the Tervueren and Groenendael varieties of the Belgian Shepherd dog breed, the disease is highly prevalent. While histopathology is the gold standard for diagnosing gastric carcinoma, there is no general consensus on the methods for histological classification in these cases. Biopsies of a group of 61 dogs with confirmed gastric carcinoma (45 Tervueren and 16 Groenendael) were examined and classified according to World Health Organization (WHO) and Laurén classifications. Kaplan-Meier curves were used to compare survival between the different subtypes and simple and multiple linear regression were used to analyse the association between age of onset and breed variant, sex, neuter status, location of the tumour, inflammation score, and Laurén and WHO classifications. Mean age at diagnosis was significantly different in Groenendael (10.1 ± 2.01) and Tervueren dogs (8.5 ± 1.90). The Laurén classification resulted in 29 (48%) diffuse- and 32 (52%) intestinal-type tumours. Applying the WHO classification resulted in 30 (49%) tubular carcinoma growth patterns and 31 (51%) others. Median survival time was significantly reduced for the diffuse type as compared to the intestinal type according to the Laurén classification, with the same median survival time results for tubular compared to non-tubular subtypes according to the WHO classification (median survival time of 61 vs. 182 days, respectively). Using the WHO and Lauren classification on tumour biopsies may help the practising clinician in the prognostication of gastric carcinoma in Tervueren and Groenendael dogs.

Oncocytic Carcinoma of Parotid Gland: A Case Report

Oncocytic carcinoma is a rare malignant carcinoma, representing only 5% of all oncocytic tumors. Furthermore, oncocytic carcinoma of the parotid gland is uncommon, accounting only for under 1% of all salivary gland tumors. We reported an 82-year-old female presented with a right parotid mass. She had experienced a similar complaint six months ago and had undergone treatment. Physical examination showed a mobile and painless cystic mass of the right parotid without facial nerve involvement. Fine needle aspiration biopsy (FNAB) finding suggested benign cystic lesions with inflammatory cells and amorphous debris. Subsequently, she underwent surgical tumor excision and right-sided partial parotidectomy. Histopathological examination showed proliferative tumor cells with an atypical nucleus, abundant eosinophilic cytoplasm, and solid, trabecular, and tubular growth pattern, suggesting an oncocytic carcinoma of the parotid gland. In conclusion, oncocytic carcinoma must be considered in all parotid gland tumors with oncocytic cells despite the rarity. Considering its recurrence and metastasis nature, patients with oncocytic carcinoma should remain in a long-term follow-up. The role of radiotherapy and chemotherapy remains controversial but may be used for treating advanced-stage cases or distant metastasis Keywords: oncocytic carcinoma; parotid gland; partial parotidectomy

A Rare Nasopharyngeal Adenoid Cystic Carcinoma: Case Report and Literature Review.

BACKGROUND Adenoid cystic carcinoma (ACC) is a malignant tumor that involves the salivary glands and is rarely seen in the nasopharynx. It is characterized by pain, a high rate of recurrence, and poor survival rate and poor prognosis as it tends to invade the perineurium. Due to the ambiguity of patient presentations, most patients present at a late stage, at which point metastasis has already occurred. CASE REPORT The patient in this case report was an otherwise healthy 56-year-old male smoker who presented to the clinic in March 2022 complaining of nasal obstruction, mouth breathing, recurrent epistaxis, headache, and facial pain. He reported significant weight loss in the past 6 months. The nasal scope showed nasopharyngeal fullness and biopsy-confirmed ACC exhibiting tubular, solid, and focal cribriform growth patterns. Further work-up showed an advanced form of nasopharyngeal ACC with intracranial extension and lung metastasis. The patient received concurrent radiotherapy and chemotherapy. After 6 months, the patient reported an improvement in the pain, and repeated images showed regression of the tumor size. CONCLUSIONS ACC is a malignant disease that is rarely seen in the nasopharynx. Currently, the most commonly agreed upon management for resectable ACCs in the literature is through surgical resection with adjuvant radiotherapy. However, most of the reported cases received radiation and chemotherapy due to the difficulty and risk of radical surgical excision of nasopharyngeal malignant tumors. Patients should be followed up to rule out any local recurrence or distant metastasis.

TFEB Rearranged Renal Cell Carcinoma: Pathological and Molecular Characterization of 10 Cases, with Novel Clinical Implications: A Single Center 10-Year Experience.

To report our experience with the cases of TFEB rearranged RCC, with particular attention to the clinicopathological, immunohistochemical and molecular features of these tumors and to their predictive markers of response to therapy. We have retrieved the archives of 9749 renal cell carcinomas in the Institute of Urology, Peking University and found 96 rearranged RCCs between 2013 and 2022. Among these renal tumors, ten cases meet the morphologic, immunohistochemical and FISH characterization for TFEB rearranged RCC. The 10 patients' mean and median age is 34.9 and 34 years, respectively (range 23-55 years old), and the male to female ratio is 1:1.5. Macroscopically, these tumors generally have a round shape and clear boundary. They present with variegated, grayish yellow and grayish brown cut surface. The average maximum diameter of the tumor is 8.5 cm and the median 7.7 (ranged from 3.4 to 16) cm. Microscopically, the tumor is surrounded by a thick local discontinuous pseudocapsule. All tumors exhibit two types of cells: voluminous, clear and eosinophilic cytoplasm cells arranged in solid sheet, tubular growth pattern with local cystic changes, and papillary, pseudopapillary and compact nested structures are also seen in a few cases. Non-neoplastic renal tubules are entrapped in the tumor. A biphasic "rosette-like" pattern, psammomatous calcifications, cytoplasmic vacuolization, multinucleated giant cells and rhabdomyoid phenotype can be observed in some tumors. A few tumors may be accompanied by significant pigmentation or hemorrhage and necrosis. The nucleoli are equivalent to the WHO/ISUP grades 2-4. All tumors are moderately to strongly positive for Melan-A, TFEB, Vimentin and SDHB, and negative for CK7, CAIX, CD117, EMA, SMA, Desmin and Actin. CK20 and CK8/18 are weakly positive. In addition, AE1/AE3, P504s, HMB45 and CD10 are weakly moderately positive. TFE3 is moderately expressed in half of the cases. PAX8 can be negative, weakly positive or moderately-strongly positive. The therapy predictive marker for PD-L1 (SP263) is moderately to strongly positive membranous staining in all cases. All ten tumors demonstrate a medium frequency of split TFEB fluorescent signals ranging from 30 to 50% (mean 38%). In two tumors, the coincidence of the TFEB gene copy number gains are observed (3-5 fluorescent signals per neoplastic nuclei). Follow-up is available for all patients, ranging from 4 to 108 months (mean 44.8 and median 43.4 months). All patients are alive, without tumor recurrences or metastases. We described a group of TFEB rearranged RCC identified retrospectively in a large comprehensive Grade III hospital in China. The incidence rate was about 10.4% of rearranged RCCs and 0.1% of all the RCCs that were received in our lab during the ten-year period. The gross morphology, histological features, and immunohistochemistry of TFEB rearranged RCC overlapped with other types of RCC such as TFE3 rearranged RCC, eosinophilic cystic solid RCC, or epithelioid angiomyolipoma, making the differential diagnosis challenging. The diagnosis was based on TFEB fluorescence in situ hybridization. At present, most of the cases reported in the literature have an indolent clinical behavior, and only a small number of reported cases are aggressive. For this small subset of aggressive cases, it is not clear how to plan treatment strategies, or which predictive markers could be used to assess upfront responses to therapies. Between the possible options, immunotherapy currently seems a promising strategy, worthy of further exploration. In conclusion, we described a group of TFEB rearranged RCC identified in a large, comprehensive Grade III hospital in China, in the last 10 years.

A Parotid Gland Mammary Analogue Secretory Carcinoma in a 4-Year-Old Boy: Case Report and Literature Review

Background: Mammary analogue secretory carcinoma (MASC) is characterized by similar histologic, immunohistochemical, and molecular features with breast secretory carcinoma. MASC usually occurs in adults. Case report: A 4-year-old boy presented with a right infra-auricular mass. Features of the tumor include solid, tubular, and papillary growth patterns, with homogenous eosinophilic secretions inside microcystic structures. Immunohistochemical stains showed strong, diffuse staining for CK7, S100, pan-TRK protein. P63 was positive in a peripheral pattern. Fluorescence in situ hybridization (FISH) analysis showed the characteristic ETV6-NTRK3 gene fusion. Conclusion: Typical histological, immunohistochemical, and molecular features are present in MASC occurring early in childhood.

Adenocarcinomas with mesonephric features in gynecologic tract: a clinicopathological analysis of seven cases

Objective: To investigate and compare the histologic characteristics of adenocarcinomas with mesonephric features located in different parts of the gynecologic tract. Methods: Two cases of mesonephric adenocarcinomas (MA) of the cervix and 5 cases of mesonephric-like adenocarcinomas (MLA) of the uterus and ovary were collected in Women's Hospital, School of Medicine, Zhejiang University from January 2018 to October 2020. Hematoxylin-eosin staining, immunohistochemistry and KRAS mutation testing were performed together with review of literature. Results: MA of the cervix as well as MLA of the uterus and ovary had similar morphologic features, showing an admixture of glandular, tubular, papillary and solid growth patterns. However, both MA cases were located in cervical stroma, which demonstrated residual mesonephric ducts present at the periphery. All four uterine MLA cases extensively involved the endometrium and myometrium. The ovarian MLA case was associated with endometriosis. No residual mesonephric ducts were present in the MLA cases. Immunohistochemically, GATA3 was positive in all seven MA/MLA cases. TTF1 was expressed only in 4/5 MLA cases. ER and PR were negative and p53 was wild-type in all cases. KRAS mutation was detected in all five cases. During the 6-32 months of follow-up, one patient developed recurrence and the others were tumor-free. Conclusions: In the gynecologic tract, both MA in cervix and MLA in uterus and ovary have similar morphologic features, immunohistochemical expression and KRAS mutation. However, distinct from MA that originates from mesonephric remnant, MLA is closely related to Mullerian epithelium.

Sinonasal low-grade non-intestinal-type adenocarcinoma: A retrospective analysis and literature review

Sinonasal low-grade non-intestinal-type adenocarcinomas (LG non-ITACs) are uncommon tumors with unclear histogenesis, although they are presumed to arise from seromucous glands or respiratory epithelium. We investigated the clinicopathological and immunohistochemical features of the tumors, with particular attention to the transition area from the normal epithelium to neoplastic cells and concurrent lesions; these features were compared with those of 10 patients with chronic sinusitis, who served as a control group. Seventeen patients with LG non-ITACs (17 tumors) were enrolled in this retrospective study (9 male patients and 8 female patients; mean age, 48 years [range, 16–74 years]). Tumor cells continuous with respiratory epithelium were detected in 10 tumors composed of a single layer of cells with papillary, tubular, or cystic growth pattern. The tumor cells were uniformly cuboidal to columnar and polar. In seven tumors without transition areas discerned, three tumors consisted of polygonal and flat cells with a solid, acinar, micropapillary and cribriform pattern. The others had the same morphology as those with transition areas. The tumor cells were positive for SOX10 (15/17), S100 protein (8/17), and CK7 (17/17). The normal epithelium connected to the respiratory epithelium was the terminal duct in the control group. Except for the lack of p63-positive cells, the immunophenotype and histomorphology of transition areas with LG non-ITACs were similar to those of the continuous areas between the terminal duct and the respiratory epithelium in the control group. LG non-ITACs are seromucinous tumors, some of which may originate from the terminal ducts of seromucinous glands.

Clinical and histopathological features and prognosis of gastrointestinal adenocarcinomas in Jack Russell Terriers.

There has been an increase in the number of Jack Russell Terriers (JRTs) diagnosed with adenomas and adenocarcinomas of the gastrointestinal tract in Japan. This study retrospectively investigated the clinical and histopathological features and prognosis of adenocarcinomas arising in the gastrointestinal tract in JRT dogs. Seven JRTs and 39 dogs of other breeds diagnosed with gastrointestinal adenocarcinoma were included in the study. The most common sites of gastrointestinal adenocarcinoma in JRTs were the pylorus and rectum. On histopathological examination, these adenocarcinomas showed a papillary or tubular growth pattern, and the lesions were confined within the mucosal epithelium and poorly invasive. Among all dogs with gastric adenocarcinoma, the median survival time (MST) for five of the JRTs could not be determined because more than half of the cases remained alive, while the MST for nine non-JRT dogs was 34 days. Among all dogs with adenocarcinoma in the large intestine, the MST for three of the JRTs could not be determined, while the MST for nine non-JRT dogs was 1,973 days. The difference in MST between JRT and non-JRT dogs with gastric adenocarcinoma was significant (P=0.0220). Since gastrointestinal adenocarcinomas in JRTs show distinct characteristics with respect to their clinical features, treatment course, and prognosis, a different surgical and medical treatment plan should be considered compared to the management of gastrointestinal adenocarcinomas in other dog breeds.

Gastric Adenocarcinoma with Enteroblastic Differentiation: A Rare Find

Abstract Casestudy: Gastric adenocarcinoma with enteroblastic differentiation (GAED), also called clear cell gastric carcinoma, is a subtype of alpha-fetoprotein (AFP) producing adenocarcinoma. GAED is not a well-documented malignancy. Due to rarity, it is often skipped from the list of gastric adenocarcinoma subtypes. We report a case of Gastric adenocarcinoma with enteroblastic differentiation in a 69-year-old male, who had an endoscopy that revealed an ulcerated, circumferential, malignant-appearing mass at the distal esophagus. The patient then underwent proximal gastrectomy with distal esophagectomy. Received was a portion of the proximal stomach and distal esophagus. On gross examination, a 2.6 cm ulcerated mass was present at the gastroesophageal junction with white, friable, and focally necrotic cut surface. H&E stained slides demonstrated a malignant tumor composed of cuboidal to columnar neoplastic cells with clear cytoplasm and prominent nucleoli. The neoplastic cells were arranged in tubular, solid, and trabecular growth patterns. There were also areas of admixed conventional moderately differentiated adenocarcinoma with overlying glandular dysplasia and focal intestinal metaplasia. Immunohistochemical stains demonstrated tumor positivity for CDX2 (strong) and AFP (focal). Neuroendocrine markers were negative within the tumor. In Conclusion, GAED is a rare malignancy with distinctive clinicopathologic features and associated aggressive behavior. Morphology and immunohistochemical stains are helpful in making the diagnosis of this rare malignancy.

Expression of selected microRNAs in pancreatic ductal adenocarcinoma: is there a relation to tumor morphology, progression and patient's outcome?

Pancreatic ductal adenocarcinoma (PDAC) remains a disease with extremely poor prognosis and limited effective available treatment. Differential expression of miRNAs isolated from tumor tissue has been proposed as a marker for tumor diagnosis, progression, and prognosis. Nevertheless, the prognostic value of miRNAs expression in PDACs for patient outcome still remains unclear. Expression of 7 selected miRNAs, isolated from FFPE samples of 54 PDAC patients, was quantified using RT-qPCR. The relationship of miRNA expression levels with tumor histology, clinicopathological characteristics, patient overall survival (OS), and progress-free survival (PFS), was subsequently evaluated. Overexpression of miR-21, miR-155, and miR-210 was observed in PDACs (up to 72.62, 232.36, and 181.38-fold, respectively), in comparison with non-neoplastic tissues. On the other hand, miR-96 and miR-217 were significantly downregulated in PDACs (up to one hundred times). No differences were, however, noticed between cancer and normal tissues for the expression levels of miR-148a and miR-196a. On the other hand, expression levels of all 7 miRNAs failed to demonstrate a significant correlation with parameters of tumor progression, such as tumor stage, grade, nodal involvement, perineural, and vascular invasion. The positive correlation of miR-210 levels was, however, observed with patient age (ρ=0.35). Additionally, miR-148a and miR-217 expressions have shown a positive association with tubular tumor growth pattern (ρ=0.39; ρ=0.28). The negative correlation of miR-148a values was also demonstrated with dissociative growth pattern and nuclear atypia (ρ=-0.30; ρ=-0.27). Finally, no statistically significant correlation could be demonstrated with the expression levels of all 7 tested miRNAs and PDAC patient survival; neither for OS nor for PFS (p>0.05). Our data have confirmed abnormal miRNAs expression in PDACs in comparison with adjacent non-neoplastic tissue. On the other hand, no correlation was discovered between miRNA expression and parameters of tumor progression. We have found a significant association between histologic tumor growth patterns and miRNA expression, making this work the first study, which analyses this aspect of PDAC. Finally, in our group of patients, no relationship of miRNA levels and patient prognosis could be demonstrated. Therefore, further investigation is required to evaluate the predictive and prognostic potential of miRNAs in a clinical setting.

A clinical, pathological and immunohistochemical series of 9 cases of primary cutaneous apocrine carcinomas of the head and neck.

Primary cutaneous apocrine carcinoma is a rare malignant adnexal skin tumour that can recur locally, spread to regional lymph nodes and metastatize to visceral organs. Wide dissemination and death from disease are much less common. The axilla is the most common site of presentation. It is infrequently reported in the head and neck region. All cases diagnosed as primary cutaneous apocrine carcinoma of the head and neck were retrospectively collected from the archives of the Division of Pathological Anatomy, University of Florence from 1996 to 2016. There was no history or clinical evidence of breast cancer. Clinical data and follow-up were collected by the clinicians. Nine cases were found, with a mean age of 76years, ranging in size between 0.3 and 3.5cm. Clinically, they were frequently mistaken for basal cell carcinomas. Histopathologically, all the tumours showed decapitation secretion, a tubular, solid or mixed (tubulo-papillary and solid-tubular) growth pattern and were predominantly classified as grade 2 tumours. GCDFP-15 and hormone receptors were variably expressed. HER2 and podoplanin were negative in all cases. In one case, spreading to regional lymph nodes was observed. No cases were associated with death due to the disease. As immunohistochemical analysis lacks specificity in distinguishing primary cutaneous apocrine carcinoma from a cutaneous metastasis of breast carcinoma, detailed clinical history, breast examination, adequate treatment and follow-up are necessary to confirm a diagnosis of primary cutaneous apocrine carcinoma.

Macrocystic (Mammary Analogue) Secretory Carcinoma: An Unusual Variant and a Pitfall in the Differential Diagnosis of Cystic Lesions in the Head and Neck.

Mammary analogue secretory carcinoma (MASC) is a relatively recently described salivary gland adenocarcinoma characterized by ETV6-NTRK3 gene fusion and in most cases indolent clinical behavior. The majority of tumors show an admixture of microcystic, solid, and tubular growth patterns but only a few cases with dominant macrocystic growth have been reported. We report 15 cases of macrocystic MASC. There were 11 men and 4 women (17 to 88 y age range, average 47 y). The patients presented with a painless cystic mass, the majority in the region of the parotid gland (n=13), as well as in submandibular gland (n=1) and the neck (n=1). All tumors were circumscribed measuring 1.0 to 4.0 cm in greatest diameter (mean: 1.75 cm). Twelve tumors were unilocular, while 3 were multilocular. The cystic spaces were predominantly lined by a single epithelial cell layer with focal areas in which the epithelium was multilayered with papillary and hobnail features. In 3 of the cases there were more solid foci of intracystic tumor characterized by papillary and/or microcystic growth. The neoplastic cells were round to oval with hyperchromatic to vesicular nuclei with centrally located nucleoli and eosinophilic or vacuolated cytoplasm. Tumor cells showed strong positivity for S100 protein and mammaglobin, while DOG1 was uniformly negative. A minority of cases showed focal p63 reactivity predominantly limited to the periphery of the cystic lining. ETV6 gene rearrangement was identified in 9 cases. Macrocystic MASC can simulate benign and malignant salivary gland lesions and needs to be included in the differential diagnosis of cystic lesions in the head and neck. To the best of our knowledge, our report represents the first series of macrocystic MASCs wholly focusing on this unusual variant.

Mesonephric adenocarcinoma of the cervix: a case report with a three-year follow-up, lung metastases, and next-generation sequencing analysis

BackgroundMesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis.Case presentationThe patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal. The patient underwent a total hysterectomy outside the institution. During biopsy, the mass showed a cerebroid aspect. Histological study revealed a tumor with a predominantly tubular and ductal growth pattern. The immunoprofile showed negative staining for calretinin, carcinoembryonic antigen (CEAm), estrogen receptors (ER), and progesterone receptors (PR), and positive staining for CD10, p16, and PAX2. The Ki-67 score was 46%. Using a next-generation sequencing assay, we documented genomic alterations in KRAS and CTNNB1, low tumor mutation burden (TMB), and an absence of microsatellite instability. In addition, gain of the long arm of chromosome 1 (1q) was also documented using chomogenic in situ hybridization (CISH). Three years later, the patient presented pulmonary nodules in the lingula and left basal lobe that were resected by thoracotomy. The histopathologic study of the pulmonary nodules confirmed the presence of metastases.ConclusionCarcinomas of mesonephric origin are among the rarest subtypes of cervical tumors. We report the first case of mesonephric adenocarcinoma of the cervix with lung metastases showing a CTNNB1 gene mutation.

High prevalence of benign mammary tumors in a rat model of polycystic ovary syndrome during postmenopausal period

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-age women. Significant associations between PCOS and benign breast diseases (BBD) and a possibly potential association between PCOS and breast cancer have been reported. The etiology of these events of mammary glands in PCOS remains unclear. Animal models that show BBD and breast cancer may contribute to further understanding about these diseases. We aimed to examine the spontaneous occurrence of mammary tumors, their prevalence, and type in our rat model of PCOS. Prenatal androgen-induced PCOS rats and controls were examined in later life. Benign mammary tumors were observed in 75% and 33.33% of PCOS rats and controls during the postmenopausal period, respectively (p = .0158). Mammary tumors were non-invasive, margins of excision were normal and tumors were freely movable, in both groups. After microscopic evaluations of tumors, proliferative breast lesions and adenomas with a tubular growth pattern were observed in both groups. However, in PCOS rats, of benign tumors two had a mixed pattern of fibroadenoma/fibroma and cysts. High prevalence of benign mammary tumors was observed in our rat model of PCOS during the postmenopausal period, possibly due to hormonal imbalances during their reproductive lifespan; this model may contribute to current data available regarding the events of mammary glands in PCOS.

PS02.092: HER2 EXPRESSION AND GENE AMPLIFICATION CORRELATES WITH BETTER SURVIVAL IN ESOPHAGEAL ADENOCARCINOMA

Abstract Background Targeting Her2 is highly established in cancers of the upper gastrointestinal tract, since clinical studies showed a survival benefit in Her2-positive gastric cancer. To date there is conflicting data concerning the impact of Her2 expression and gene amplification in esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the esophagus, gastroesophageal junction and stomach. The aim of this study was to analyze the expression and gene amplification of Her2 in EAC in correlation to clinical and pathological data to verify the prognostic impact. Methods We analyzed 506 patients with esophageal adenocarcinomas that underwent thoraco-abdominal esophagectomy between 1997 and 2013 using a tissue micro array (TMA) for the expression of Her2 by immunohistochemistry (IHC) according to the guidelines. Fluorescence-in-situ-hybridization (FISH) was performed for IHC score 2. The Her2-status was correlated with clinical and pathological data. Results Her2-positivity was found in 11.7% (n = 59) of all EAC (IHC score 3 + or IHC score 2 + with amplification) and demonstrated a significant better overall-survival (OS) in correlation to Her2-negative tumors (median OS 55.0 vs. 22.7 months, P < 0.0001) (Figure below). Overexpression of Her2 was associated with lower tumor stages (pT1/pT2, P = 0.038), absence of lymph node metastases (pN0/pN + , P = 0.030) and was significantly associated with tubular and/or papillary tumor growth pattern (P = 0.029). Conclusion We demonstrated a positive prognostic impact of Her2 expression and gene amplification in a large cohort of EAC, contrary to other solid malignancies including gastric cancer, but according to a large study of EAC from 2012. Her2-positive tumors significantly have a tubular and/or papillary tumor growth pattern, indicating a marker of differentiation in EAC. Disclosure All authors have declared no conflicts of interest.

The case for the omission of axillary staging in invasive breast carcinoma that exhibits a predominant tubular growth pattern on preoperative biopsy.

True invasive tubular breast carcinoma (TBC) is unlikely to metastasize to axillary nodes, yet it is routinely subjected to sentinel lymph node biopsy (SLNB), even if the diagnosis was suspected preoperatively. The positive predictive value (PPV) of core biopsy for TBC and the incidence and predictors of axillary metastasis in invasive breast carcinomas identified as tubular-rich on core biopsy are unknown. Prospective patient and tumor data regarding postoperatively confirmed TBCs, and tubular-rich carcinoma identified on preoperative core biopsy between January 2005 and May 2016 was analyzed retrospectively. Axillary metastasis occurred in only 4.2% (4/95) of TBCs, all of which measured >15 mm pathologically. In 11.1% (11/99) of TBCs, the initial core biopsy was either indeterminate/suspicious or ductal carcinoma in situ (DCIS); therefore, their true tubular histotype and size were ascertained following operative excision and before SLNB. Nine were ≤15 mm, and all were node-negative. Only 63.9% (46/72) of tubular-rich core biopsies were confirmed as TBCs; the remaining 36.1% (26/72) were well-differentiated invasive nontubular carcinomas. None of the preoperative patient or tumor features were predictive of true TBC on multivariable analysis; 10.1% (7/69) of carcinomas identified as tubular-rich on core biopsy (regardless of their true histotypes) were node-positive; 23.1% (6/26) in nontubular and 2.3% (1/43) in true tubular carcinomas. Preoperative ultrasound size >15 mm was associated with axillary metastasis in 40.0% (4/10) compared to 5.7% (3/53) in those ≤15 mm (OR = 11.11, 95% CI = 1.99-62.04; multivariable P = .010). Axillary metastasis in TBC is dependent on pathological size; therefore, a case is made for omitting SLNB in small true TBCs confirmed following excision. Preoperative tubular-rich core biopsy is not adequately diagnostic of TBC; however, it selects carcinomas that are well-differentiated, small, and unlikely to metastasize to the axilla, thus allowing for the selective omission of SLNB.