Mark J. Mentrikoski

GATA3 expression in morphologic subtypes of breast carcinoma: a comparison with gross cystic disease fluid protein 15 and mammaglobin

GATA3 is a transcription factor, which is involved in the growth and differentiation of several human tissues. Immunohistochemical staining for this marker has proven to be useful in recognizing a number of tumors, most notably those in the urinary tract and breasts. To date, no study has specifically assessed the distribution of GATA3 among different histomorphologic subtypes of breast carcinoma. The surgical pathology archive at our institution was searched, to retrieve cases of breast carcinomas of the following microscopic types-ductal, lobular, mucinous, metaplastic, medullary, apocrine, signet-ring cell, and micropapillary. Tissue microarrays were created, with four 0.6-mm punch specimens from each case. The tissue microarrays were cut at a 5-μm thickness and stained with monoclonal antibodies to GATA3 (Biocare Medical Inc, Concord, CA), mammaglobin (Dako, Carpinteria, CA), and gross cystic disease fluid protein 15 (Dako). Tumors were considered to be positive for those markers if more than 5% of the cells were labeled. Of 55 ductal adenocarcinomas, 51 (92.7%) expressed GATA3. All 4 GATA3-negative tumors were Nottingham grade III lesions that were also nonreactive for estrogen receptor protein. GATA3 was present in 28 (96.6%) of 29 lobular adenocarcinomas, 10 (90.9%) of 11 apocrine adenocarcinomas, 10 (83.3%) of 12 medullary carcinomas, 5 (55.5%) of 9 metaplastic carcinomas, and 1 of 2 signet-ring cell carcinomas. Mucinous carcinomas (23 cases) and micropapillary carcinomas (12 cases) uniformly and strongly labeled for GATA3. GATA3 equaled or surpassed the sensitivity of mammaglobin and gross cystic disease fluid protein 15 in all histologic subgroups of breast cancer in the study. Although most ductal adenocarcinomas were labeled for GATA3, it was absent in high-grade tumors that also lacked estrogen receptor protein. Favorable prognosis types of breast carcinoma (eg, mucinous carcinoma) and aggressive variants such as micropapillary carcinoma were equally reactive for this marker. A proportion of medullary and metaplastic carcinomas was GATA3 negative (17% and 44%, respectively). Thus, those pathologic entities cannot be excluded diagnostically by an absence of GATA3 immunoreactivity.

Immunohistochemical distinction of primary sweat gland carcinoma and metastatic breast carcinoma: can it always be accomplished reliably?

OBJECTIVES Even with adequate history, the distinction of cutaneous metastatic breast carcinoma from primary sweat gland carcinoma can be difficult. Although previous studies have attempted to separate these tumors with various immunohistochemical panels, those series have been limited by small numbers of patients as well as the inclusion of benign sweat gland tumors. METHODS In this analysis, stains for p63, CK5/6, and D2-40 were included, as well as GATA3 and mammaglobin, in an evaluation of 21 primary sweat gland carcinomas and 33 examples of cutaneous metastatic breast carcinoma. RESULTS Immunoreactivity for p63, CK5/6, D2-40, GATA3, and mammaglobin was respectively observed in 81%, 71%, 52%, 71%, and 5% of sweat gland carcinomas compared with 6%, 6%, 6%, 91%, and 45% of metastatic breast carcinomas. These differences were statistically significant for p63, CK5/6, and D2-40. For the diagnosis of metastatic breast carcinoma, GATA3 was the most sensitive marker (91%), but its sensitivity was substantially lower. Mammaglobin was 95% specific for breast carcinoma but again suffered from limited sensitivity (45%) in this context. CONCLUSIONS These data suggest that p63 and CK5/6 are specific determinants for sweat gland carcinoma in the stated setting. In the absence of those analytes, metastatic breast carcinoma cannot always be identified to the exclusion of a primary tumor. This diagnostic scenario continues to require the procurement of a detailed clinical history regarding the number and duration of skin lesions in any given case.

Immunohistochemical distinction of renal cell carcinoma from other carcinomas with clear-cell histomorphology: utility of CD10 and CA-125 in addition to PAX-2, PAX-8, RCCma, and adipophilin.

Clear-cell renal cell carcinoma (CC-RCC) is the most common primary kidney malignancy, yet this morphology is not unique to renal primary tumors, as clear-cell variants of numerous nonrenal carcinomas of varying lineages exist. Therefore, because of CC-RCC’s ability to metastasize to nearly any anatomic location, ancillary studies such as immunohistochemistry are often needed to establish the diagnosis. Despite CD10 and renal cell carcinoma monoclonal antibody (RCCma) being touted as sensitive and specific markers, some have suggested that more recent stains including PAX-2, PAX-8, or adipophilin (ADP) are more robust markers of CC-RCC. In this study, 26 cases of CC-RCC, and 51 nonrenal carcinomas with clear-cell histomorphology (CCM) were stained with CD10, RCCma, PAX-2, PAX-8, and ADP. CA-125 was also included to help distinguish CC-RCC from Müllerian clear-cell carcinomas, due the known expression of PAX-2 and PAX-8 in both these entities. RCCma highlighted 77% of CC-RCC and 27% of the CCM group, whereas CD10 was positive in 85% and 25%, respectively. ADP highlighted all CC-RCC and 45% of CCMs. PAX-2 was positive in 81% of CC-RCC and 24% of CCM, whereas PAX-8 stained 100% of CC-RCC and 39% of CCM. Müllerian-derived tumors (clear-cell carcinomas of the ovary, vagina, and cervix) were positive with PAX-2 and PAX-8 in 69% and 100% of cases, respectively. No cases of CC-RCC stained with CA-125, whereas 88% of the Müllerian-derived tumors were positive. In summary, although new markers such as PAX-2 and PAX-8 tend to be more sensitive markers of CC-RCC, they lose specificity when Müllerian tumors are included. Inclusion of a classic renal marker such as CD10 or RCCma in the immunohistochemical panel, as well as CA-125 obviates this difficulty.

Assessing Endometrial Hyperplasia and Carcinoma Treated With Progestin Therapy

The effects of increased amounts of progesterone on the endometrium, including such features as eosinophilic cytoplasmic metaplasia, glandular atrophy, and decidualized stroma, are well-known among surgical pathologists. These changes are typically seen as secondary effects of pregnancy or exogenous hormone therapy for birth control purposes or abnormal bleeding. Treatment with progesterone has become a viable alternative to hysterectomy in some patients with complex atypical hyperplasia (CAH) and well-differentiated endometrial carcinoma (WDC), especially those who are poor surgical candidates or those wishing to preserve fertility. To date, only 1 study has specifically examined the effects of progestin therapy on patients with a previous diagnosis of CAH or WDC. That study proposed a classification scheme for the assessment of treated CAH and WDC. The authors concluded that after 6 months of treatment, endometrial biopsy findings of persistent cytologic atypia and architectural abnormalities were associated with treatment failure. This current study aims to assess the previously proposed criteria in a cohort of 30 patients (18 with a diagnosis of CAH and 12 with a diagnosis of WDC), and determine the usefulness of these criteria in clinical practice. Our study confirms that cytologic atypia after 6 months of therapy is strongly associated with treatment failure, and should be an indication to pursue definitive surgical treatment in these patients.

Histologic and immunohistochemical assessment of penile carcinomas in a North American population.

Penile squamous cell carcinoma (SCC) is sometimes an aggressive disease that has a variable worldwide incidence, in part due to differing rates of inflammatory and infectious risk factors. In the developed world, penile SCC is a rare malignancy, and most studies therefore originate in less developed countries. The current study was undertaken to examine the morphologic and immunohistochemical features of penile SCC from a region with low disease incidence. Sixty-two complete or partial penectomy specimens from 59 patients were reviewed. Twenty-six patients had metastasis, 3 had recurrent disease, and 7 were dead due to tumor. Most patients were uncircumcised (72%). Twenty-two percent of carcinomas were associated with lichen sclerosis. Perineural invasion was significantly associated with metastasis (P=0.007). Most SCCs (65%) had the usual keratinizing morphology, and these tumors were significantly associated with the differentiated form of intraepithelial lesion (P<0.0001), p53 positivity (P=0.002), cyclin D1 positivity (P=0.007), and EGFR overexpression (P=0.003). Human papilloma virus (HPV)-associated tumors accounted for 27% and were basaloid (8%), warty (10%), mixed (6%), or lymphoepithelioma-like carcinoma (4%) variants. These were significantly associated with p16 expression (P<0.0001) and the undifferentiated form of intraepithelial lesion (P<0.001). Among all SCCs, there was no difference in the immunohistochemical or in situ hybridization profile between primary tumors and metastases. Although penile SCC is rare in the United States, the tumor variants, immunohistochemical profiles, and proportion of HPV-associated tumors are similar to those in less developed countries. Two distinct pathways appear to lead to carcinogenesis; one is related to underlying chronic inflammatory states, involves p53 mutation, cyclin D1 overexpression, and culminates in classic keratinizing SCC. The other pathway involves high-risk HPV infection, demonstrates strong p16 expression, and results in SCC with varied, but distinctive morphologies.

Lymphoepithelioma‐like carcinoma of the penis: association with human papilloma virus infection

chemistry for cleaved caspase-3 (CC3). Wang et al. reported a reduced level of apoptosis in adenomatous lamina propria (with lower mean counts) compared with non-dysplastic melanotic lamina propria, and increased apoptosis (with higher mean counts) in the adenomatous epithelium. They endorse the hypothesis that impaired absorption of apoptotic debris or loss of the apoptotic material into the lumen ‘is responsible for the lack of the pigmentation in adenomas’. However, in a recent paper the author described 10 cases of hyperplastic polyps and two cases of adenomata, all with melanosis present within the hyperplastic/neoplastic lamina propria. In one of the latter cases there were multiple tubulovillous adenomata, all showing melanosis coli (Figure 1). In addition, 10 melanotic hyperplastic polyps were also found to have melanosis coli, usually more extensive, in the biopsied colonic epithelium (Figure 2). Moreover, a single case report describing melanosis in a tubular adenoma has also been documented. The question of causality and correlation therefore arises. If the proposed pathogenetic mechanism is correct the conclusion, therefore, is perhaps more one of degree rather than absolutism. In most, but not all, neoplastic/ hyperplastic colonic lesions, apoptotic fragments remain in the neoplastic epithelium or are lost intraluminally and do not reach the lamina propria. Consequently, rare hyperplastic polyps and rarer adenomas do show melanosis.

Basal cell carcinoma vs basaloid squamous cell carcinoma of the skin: an immunohistochemical reappraisal

Typical cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are morphologically dissimilar. It is well known, however, that poorly differentiated SCC may assume a basaloid phenotype, complicating the histologic distinction between these 2 neoplasms. Selected immunohistochemical stains have been used in the past to aid in that differential diagnosis. In the current study, additional markers were evaluated to determine whether they would be helpful in that regard. Twenty-nine cases of metatypical (squamoid) BCC (MBCC) and 25 examples of basaloid SCC (BSCC) were studied using the antibodies Ber-EP4 and MOC-31 as well as a plant lectin preparation from Ulex europaeus I (UEA-1). The resulting immunostains were interpreted independently by 3 pathologists, and the results showed that MBCCs demonstrated strong and diffuse staining for Ber-EP4 (25/29) and MOC-31 (29/29). In contrast, BSCCs tended to be only sporadically reactive for both markers (4/25 and 1/25 cases, respectively). Labeling for UEA-1 was observed in almost all BSCCs (24/25), but only 6 of 29 cases of MBCC showed limited, focal staining with that lectin. These data suggest that MOC-31 is a useful marker in the specified differential diagnosis, especially when used together with UEA-1.

Endoluminal Negative-Pressure Therapy for Preventing Rectal Anastomotic Leaks: A Pilot Study in a Pig Model

BACKGROUND Anastomotic leak after rectal resection carries substantial morbidity and mortality. A diverting ileostomy is beneficial for high-risk anastomoses, but its creation and reversal carry a surgical risk in addition to that of resection itself. We sought an alternative method for managing complications of rectal anastomosis. METHODS We developed an endoluminal negative-pressure technology with a diverting proximal sump, and hypothesized that it would close anastomotic disruptions in pigs. We performed rectal resections on pigs, with primary anastomoses and the creation of an anastomotic defect. In animals in the treatment group we inserted an endoluminal negative-pressure device and kept it at a low level of continuous suction for 5 d. No device was inserted in a control group of animals. After the 5-d period of treatment we evaluated the anastomoses in both the treatment and control groups of animals for leakage, using contrast enemas. Specimens of anastomosed rectum were evaluated histologically for mucosal integrity and for the location and density of inflammatory responses. RESULTS Fourteen pigs were assigned to either the treatment (n=10) or control (n=4) group. Of the pigs in the treatment group, 90% had complete closure of their rectal defect, as compared with 25% of the animals in the control group (χ(2) test, p=0.04). The animals in the treatment group had only minimal mucosal and serosal inflammation, whereas those in the control group had extensive mucosal damage with associated serositis. CONCLUSIONS Endoluminal negative-pressure therapy was well-tolerated and led to successful closure of 90% of the anastomic rectal defects in the treatment group of animals in the present study. Additional evaluation of this therapy is warranted.

HER2 immunohistochemistry significantly overestimates HER2 amplification in uterine papillary serous carcinomas.

Recently, there have been numerous reports showing that HER2 overexpression or amplification occurs in a variable number of uterine papillary serous carcinoma (UPSC) cases, leading to a current clinical trial targeting this pathway. Although approved algorithms exist for scoring HER2 overexpression/amplification in breast and gastroesophageal carcinomas, scoring criteria and the optimal methodology for assessing HER2 in UPSC are currently unknown. Most frequently, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) breast carcinoma algorithms have been utilized for UPSC, wherein cases are screened with immunohistochemistry (IHC), followed by fluorescence in situ hybridization for equivocal cases. However, interpreting HER2 IHC can be prone to significant subjectivity, often leading to false-positive results. To better correlate HER2 IHC results with underlying amplification in UPSC, we compared HER2 overexpression by IHC with HER2 amplification with chromogenic in situ hybridization (CISH). A total of 69 cases of UPSC—57 pure and 12 mixed—were identified over a 10-year period. All were included in a tissue microarray, and HER2 IHC and CISH were performed. Each case was scored according to the most recent 2013, as well as the 2007, ASCO/CAP scoring guidelines for breast carcinoma. Whole-tissue sections were also examined in cases with amplification by CISH on initial screening, as well as an equal number of negative cases, to account for intratumoral heterogeneity. Nine (13%) cases showed HER2 amplification by CISH, whereas 14 (20%) and 28 (40%) cases showed overexpression with IHC when the 2007 or 2013 ASCO/CAP criteria were utilized, respectively. The overall concordance rate between CISH and IHC was 64% (9/14) with the 2007 ASCO/CAP criteria and 32% (9/28) with the 2013 ASCO/CAP criteria. Intratumoral heterogeneity was seen in 3 (33%) amplified cases. No additional amplified cases were identified on subsequent whole-section examination after the initial negative tissue microarray screening. While confirming that HER2 amplification is found in a subset of UPSC, our results also show that screening with IHC will overestimate the number of cases showing underlying HER2 gene amplification. The significant discordance between methods in our study suggests that optimal HER2 testing parameters in UPSC are yet to be defined. Future clinical trials should incorporate both IHC and ISH results for each patient in their study design, so that conclusions can finally be made about which method is ultimately a better predictor of treatment response.

Delayed Endoluminal Vacuum Therapy for Rectal Anastomotic Leaks after Rectal Resection in a Swine Model: A New Treatment Option

Anastomotic leaks are a dreaded surgical complication following colorectal operations. Creation of a temporary proximal diverting ileostomy is used in high‐risk anastomoses, however, additional surgical risk is accumulated with its creation and reversal. Endoluminal vacuum therapy has been shown to seal anastomotic defects in the prophylactic setting in a pig model and we hypothesized it could be utilized in a delayed fashion to rescue subjects with an active anastomotic leak. Yorkshire pigs underwent rectal resection, intentional leak confirmed by fluoroscopy, and endoluminal vacuum therapy device placement to low continuous suction. Following treatment, a contrast enema and necropsy was performed for gross and histopathology. Pigs underwent 2 (or 5) days of free intraperitoneal leak prior to device placement and 5 (or 7) subsequent days of endoluminal vacuum therapy. Six of seven early‐treated pigs sealed their anastomotic defect, while two of the four treated pigs in this extended group sealed the defect. Endoluminal vacuum therapy is feasible and well tolerated in a pig model, and it has been shown to seal a significant number of freely leaking anastomoses in the early period (86%). This technology warrants further study as it may provide a noninvasive means to treatment of anastomotic leaks.