Pulmonary adenocarcinoma with micropapillary component: an immunohistochemical study. Case report

The presence of extensive retraction clefts in invasive breast carcinomas correlates with lymphatic invasion and nodal metastasis and predicts poor outcome: a prospective validation study of 2742 consecutive cases

We previously reported that the presence of extensive retraction clefts (RC) in breast cancers correlates with increasing tumor size and grade as well as lymphatic tumor spread and predicts poor outcome. This study is a prospective validation of our prior results. Consecutive cases of invasive breast carcinoma (n=2742) were reviewed to determine the diagnoses, including histologic type, grade, presence of lymphovascular invasion (LVI), and extent of RC. No differences were found in the extent of RC between corresponding core needle biopsy and surgical samples. Extent of RC showed a significant correlation with tumor size, grade, LVI, and nodal metastasis in both core needle biopsy and surgical specimens. These associations remained significant in subset analyses of small (≤1 cm), node-negative and node-positive tumors. Extensive RC predicted poor recurrence-free (P<0.0001) and overall (P<0.0001) survival and remained significant in subset analyses of node-negative (P=0.0015 and 0.0021, respectively) and node-positive (P=0.0039 and 0.0214, respectively) cases. Carcinomas without LVI but extensive RC were associated with better outcome than carcinomas with LVI but worse than those without LVI and low RC. This prospective study confirms that the presence of extensive RC in invasive breast carcinomas correlates with aggressive tumor features and lymphatic tumor spread. Extensive RC appears to be an independent factor predictive of poor outcome in node-negative and node-positive disease. Our results support the hypothesis that RCs are the morphologic reflection of biological changes in tumor cells playing a role in lymphatic tumor spread and likely represent an early stage of LVI with similar clinical implications.

Invasive micropapillary carcinoma of the extrahepatic bile duct and its malignant potential

Invasive micropapillary carcinoma (IMPC) was originally described as a distinctive type of invasive carcinoma in the breast, but it has not been recognized as a histological type of the extrahepatic bile duct cancer. The present study demonstrated clinicopathological features and patient prognosis of IMPC. We examined histological reviews of 93 consecutive cases of the extrahepatic bile duct cancer and identified 13 cases which included IMPC component. The component of IMPC ranged from 5 to 60% of the primary tumor tissue, which was mainly detected at the invasive front of the tumor. Of the 13 cases, 12 (92.3%) carcinomas with IMPC showed lymph node metastasis more frequently compared to conventional adenocarcinoma (39.2%, P<0.001). Presence of IMPC component was significantly associated with poor overall survival (P=0.003). In conclusion, extrahepatic bile duct carcinoma with IMPC component showed significant lymphatic invasion, lymph node metastasis, and resulted in poor prognosis.

Tumor islands in resected early-stage lung adenocarcinomas are associated with unique clinicopathologic and molecular characteristics and worse prognosis

Tumor islands-large collections of tumor cells isolated within alveolar spaces-can be seen in lung adenocarcinomas. Recently we observed by 3-dimensional reconstruction that these structures were connected with each other and with the main tumor in different tissue planes, raising the possibility of tumor islands being a means of extension. However, the clinical and prognostic significance of tumor islands remains unknown. In this study, we compared clinicopathologic and molecular characteristics and prognosis of stages I to II lung adenocarcinomas with tumor islands (n=58) and those without (n=203). Lung adenocarcinomas with tumor islands were more likely to occur in smokers, exhibit higher nuclear grade and a solid or micropapillary pattern of growth, and harbor KRAS mutations. In contrast, lung adenocarcinomas without tumor islands were more likely to present as minimally invasive adenocarcinoma, show a lepidic pattern of growth, and harbor EGFR mutations. Although there was no difference in stage, the prognosis of lung adenocarcinomas with tumor islands was significantly worse than those without. The 5-year recurrence-free survival for patients with tumor islands and those without was 44.6% and 74.4%, respectively (log rank P=0.010). The survival difference remained significant (P <0.020) by multivariate analysis, and the presence of tumor islands was associated with almost 2-fold increase in the risk of recurrence. Even in the stage IA cohort, more than half of the patients with tumor islands experienced recurrence within 5 years. Thus, aggressive surveillance and/or further intervention may be indicated for patients whose tumors exhibit tumor islands.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma

INTRODUCTION

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies.

METHODS

An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach.

RESULTS

The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized.

CONCLUSIONS

This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

The presence of micropapillary features and retraction artifact in core needle biopsy material predicts lymph node metastasis in breast carcinoma

Retraction artifact around tumor cell nests is a characteristic feature of invasive micropapillary carcinoma (IMPC), a special type of breast cancer commonly associated with nodal metastasis. We have recently reported that the extent of retraction artifact in usual invasive ductal carcinomas (IDC) is also a strong predictor of nodal metastasis. We examined whether the presence and extent of micropapillary features and retraction artifact in core needle biopsy of breast cancers can predict nodal metastasis in a prospective series of 47 IMPC and 424 IDC. Micropapillary features were present on core needle biopsy in 28 of 47 IMPC cases. Nodal metastases were found in 21 of 28 and 14 of 19 IMPC cases with and without micropapillary features present on core needle biopsy, respectively. Lymph node metastasis was significantly associated with the presence of micropapillary features, but not with its extent within these tumors. The presence of extensive retraction artifact in core needle biopsy samples of IDC also showed a significant association with nodal metastasis. Our results indicate that the presence of micropapillary features or extensive retraction artifact on core needle biopsy of breast carcinoma can predict nodal metastasis. Our results support the notion that the characteristic clear spaces separating the tumor cells from the stroma in IMPC and IDC of the breast are not a random artifactual phenomenon simply resulting from tissue fixation and processing, but rather they are likely related to altered tumor-stromal interactions, which might have an important role in lymphatic tumor spread.

Lung adenocarcinoma with micropapillary component presenting with metastatic scrotum tumor and cancer-to-cancer metastasis: A case report

A 54-year-old man was admitted to the hospital presenting with a 3-month history of sclerosing dermal lesion in the external genitalia. A scrotal skin biopsy revealed a poorly-differentiated adenocarcinoma, immunohistochemically positive for cytokeratin 7 (CK7) and for thyroid transcription factor 1 (TTF-1), and negative for CK20. One month after admission, he died of respiratory failure. At autopsy, a consolidating lesion with vague margin was noted in the left lung as well as a well-circumscribed nodule in the right lobe of the thyroid. Histopathologically, pulmonary lesion was adenocarcinoma with a micropapillary component. On the other hand, thyroid tumor was diagnosed as a follicular variant of papillary carcinoma with foci of micropapillary adenocarcinoma. Positive immunohistochemistry for surfactant protein on micoropapillary component was useful to confirm that micropapillary component was of lung adenocarcinoma origin.

Invasive micropapillary carcinoma of the colon: an immunohistochemical study

Invasive micropapillary carcinoma has recently been reported in various anatomic sites. In this article, we report a case of micropapillary carcinoma of the sigmoid colon. A 70-year-old Japanese woman presented with bloody stool for 2 months. Detailed examination disclosed ulcerative and localized tumor in the sigmoid colon. Histological examination of the colon tumor showed a combination of conventional adenocarcinoma (60%) and micropapillary carcinoma (40%). Immunohistochemically, micropapillary carcinoma cells were positive for cytokeratin (CK) 20, carcinoembryonic antigen, and CA125, but negative for CK7, thyroid transcription factor-1, surfactant apoprotein A, estrogen receptor, and progesterone receptor. Additionally, the immunohistochemistry of epithelial membrane antigen revealed reverse polarity of neoplastic cells. Results of conventional adenocarcinoma were basically identical to those of micropapillary carcinoma. In the stroma of both conventional adenocarcinoma and micropapillary carcinoma, many myofibroblasts were present and CD34-positive stromal cells were absent. Finally, we report the fourth case of micropapillary carcinoma arising in the colon. Immunohistochemical results of CK7(-)/CK20(+) strongly suggest the colon as a primary site of micropapillary carcinoma. Additionally, micropapillary carcinoma of the colon may cause a similar stromal reaction to conventional adenocarcinoma of the colon.

Pleomorphic ductal carcinoma of the breast with predominant micropapillary features

An 83-year-old woman with long-standing chronic ischemic cardiac and obstructive pulmonary disease, presented with a painless tumor in her right breast. Microscopically the tumor consisted of micropapillary formations and loosely cohesive nests and strands of large, highly pleomorphic cells. Micropapillary formations were surrounded by peritumoral retraction clefting, and the papillae lacked a true fibrovascular core. Multinucleated giant and bizarre tumor cells were also present and numerous. Within the tumor a high-grade intraductal component with the same cell morphology and necrosis and mucin production was found. Micropapillary pattern occupied approximately 60% of the tumor mass, loosely cohesive nests and strands approximately 20% and an intraductal component was noted in approximately 20% of the tumor mass. On immunohistochemistry the tumor cells were positive for pan-cytokeratin, epithelial membrane antigen (EMA), S100 protein and E-cadherin while estrogen and progesterone receptors, HER2-neu and Bcl2 were negative. EMA staining was diffuse and observed in the outer and inner margins of neoplastic nests. The diagnosis of pleomorphic breast carcinoma with predominant micropapillary features was established. In summary, micropapillary carcinoma can be distinguished from other types of breast carcinoma with micropapillary growth pattern on the basis of reverse cell polarity, which is easily confirmed on immunohistochemistry.

A micropapillary pattern is predictive of a poor prognosis in lung adenocarcinoma, and reduced surfactant apoprotein A expression in the micropapillary pattern is an excellent indicator of a poor prognosis

A micropapillary pattern is defined as papillary tufts without a fibrovascular core and is known to be a factor that indicates a poor prognosis in numerous cancers. However, their role in lung adenocarcinoma has not been investigated widely. In 185 cases of small-size lung adenocarcinoma (< or =3 cm), cases with a micropapillary pattern ratio of more than 1% (analyzed by NIH image) were defined as micropapillary pattern positive. Correlations between the micropapillary pattern and clinicopathological factors were investigated and immunohistochemical expression of mucin and various antigens was examined in regions with and without micropapillary patterns. Micropapillary pattern-positive tumors (micropapillary pattern ratio > or =1%) were observed in 11.4% of cases (21/185) and the micropapillary pattern ratio correlated with TNM stage (P=0.0002), lymphatic invasion (P=0.0002) and lymph node metastasis (P=0.03). Disease-free interval (P<0.0002) and survival (P=0.027) were significantly shorter for micropapillary pattern-positive patients, and micropapillary pattern-positive stage IA cases also had a significantly shorter disease-free interval (P<0.0001). MUC1 was expressed strongly across the surface of the micropapillary structure, whereas MUC4 tended to show lower expression in the micropapillary pattern. It was noteworthy that the disease-free interval in patients with high surfactant apoprotein A expression was significantly better than in patients with low surfactant apoprotein A expression (P=0.03), and no recurrence or death occurred in patients with high surfactant apoprotein A expression. Our results show that the micropapillary pattern ratio correlates with lymphatic invasion and lymph node metastasis, and that a high micropapillary pattern ratio leads to a poor prognosis. High MUC1 expression on the surface is an important characteristic of a micropapillary pattern, and reduced surfactant apoprotein A expression in the micropapillary pattern may be an excellent indicator for poor prognosis in small-size lung adenocarcinoma.

Extensive retraction artifact correlates with lymphatic invasion and nodal metastasis and predicts poor outcome in early stage breast carcinoma

Retraction artifact resulting in clear spaces around tumor cell nests is frequently seen in histologic material and may present difficulty in their differentiation from lymphovascular invasion. We noticed that retraction artifact seemed to be more common around groups of breast cancer cells compared with benign acini, and when extensively present, metastasis to axillary lymph nodes was often seen. Thus, we performed a study of 304 cases of stage pT1 and pT2 breast carcinomas to test our hypothesis that extensive retraction artifact in tumors correlates with lymphatic spread and outcome. Tumors were evaluated to determine the presence and extent of retraction artifact around tumor cell nests and the presence of lymphatic invasion. Lymphatic invasion was confirmed by D2-40 immunostaining. The extent of retraction artifact in tumors was correlated with clinicopathologic tumor features and patient outcome. Variable degree of retraction artifact was present in 183 of 304 (60%) invasive carcinomas, with its extent ranging from 0% to 90% (median 5%). The extent of retraction artifact showed a significant correlation with tumor size, histologic type, histologic grade, presence of lymphovascular invasion, and nodal metastasis. Further, extensive retraction artifact was significantly associated with poor overall and disease-free survival in both univariate and multivariate analyses. We propose that the apparent retraction of the stroma from cells of invasive breast carcinoma on routine histologic sections is not a phenomenon merely due to inadequate fixation as currently believed. Rather, it likely signifies important biologic changes that alter tumor-stromal interactions and contribute to lymphatic spread and tumor progression.

Lung adenocarcinoma with a micropapillary pattern: a clinicopathological study of 25 cases

Lung adenocarcinoma with a micropapillary pattern has recently been described, but its biological behavior is as yet uncertain. In this article we present a clinicopathological study of lung adenocarcinoma with micropapillary morphology. We selected 25 patients with lung adenocarcinoma with micropapillary morphology from the 2001-2004 pathology files (age range 54 to 81 years; mean 64.5 years). Micropapillary carcinoma is predominantly located at the periphery of the tumor nodule or mass and occurs irrespective of the subtype of the adenocarcinoma. A micropapillary component was seen against a mucinous background in three cases and microcalcifications resembling psammoma bodies were seen in one case. Four cases showed intensive invasive growth such as micropapillary adenocarcinoma of the breast and 21 showed alveolar type morphology with piling-up of the neoplastic cells with or without stromal invasion. Seven of twenty-three (30.4%) showed lymph node metastases at time of operation. Twelve of twenty-five (48%) showed pleural invasion. Regarding clinical outcome, 14 patients were alive without disease, 5 were alive with disease, and 5 died of the lung adenocarcinoma. No significant relationship was found between the extent of the micropapillary component and prognosis. However, the carcinoma seen in the five patients who died showed breast type histology with intensive invasive growth in three cases and alveolar type histology with intensive stromal invasion in two. Lung micropapillary carcinoma of breast type may behave more aggressively than the alveolar type.

Intracytoplasmic lumina in invasive micropapillary carcinoma of the lung

Micropapillary carcinoma of the lung is a rare neoplasm, and several reports on micropapillary carcinoma of the lung have been presented to date. We present a case of micropapillary carcinoma of the lung here. A 75-yr-old Japanese man received the medical checkup and his chest X-ray disclosed the abnormal shadow of the lower lobe of the left lung. The histological examination of resected lung and extirpated lymph node showed the finding of micropapillary carcinoma. Some neoplastic cells of primary site contained intracytoplasmic lumina positive for Alcian blue and PAS stains. Pleural effusion appeared 9-mo after the operation. The cytology of pleural effusion showed cohesive clusters of neoplastic cells consisting of 3-20 cells without fibrovascular core. Additionally, intracytoplasmic lumina were observed in some neoplastic cells. Finally, carcinoma cells with micropapillary morphology may possess the intracytoplasmic lumina in the cytoplasm of metastatic site as well as primary site.

Female urethral adenocarcinoma with a heterogeneous phenotype. Case report

We here report a very rare case of female urethral adenocarcinoma. A 77-year-old woman presented with urinary retention. Cystoscopy showed a urethral tumor and the biopsy material showed adenocarcinoma. Macroscopically, the tumor measuring 3.0 x 3.0 x 2.4 cm was predominantly observed around the periurethral area on the proximal side. Histologically, patterns of columnar/mucinous adenocarcinoma, clear cell adenocarcinoma and papillary/micropapillary carcinoma were observed, but there was no evidence of a cribriform pattern. Immunohistochemically, neoplastic cells of at least one of three components were positive for CK7 and CK20 or CA125. We suggest that female urethral adenocarcinoma with a histologically and immunohistochemically heterogeneous phenotype may originate from cells within urethral or paraurethral tissue, such as urethritis glandularis or intestinal metaplastic epithelium and Mullerian tissue.