Immunohistochemistry of solid tumors. Brief review of selected problems

Quantitative phase imaging for medical diagnosis

Optical microscopy is an indispensable diagnostic tool in modern healthcare. As a prime example, pathologists rely exclusively on light microscopy to investigate tissue morphology in order to make a diagnosis. While advances in light microscopy and contrast markers allow pathologists to visualize cells and tissues in unprecedented detail, the interpretation of these images remains largely subjective, leading to inter- and intra-observer discrepancy. Furthermore, conventional microscopy images capture qualitative information which makes it difficult to automate the process, reducing the throughput achievable in the diagnostic workflow. Quantitative Phase Imaging (QPI) techniques have been advanced in recent years to address these two challenges. By quantifying physical parameters of cells and tissues, these systems remove subjectivity from the disease diagnosis process and allow for easier automation to increase throughput. In addition to providing quantitative information, QPI systems are also label-free and can be easily assimilated into the current diagnostic workflow in the clinic. In this paper we review the advances made in disease diagnosis by QPI techniques. We focus on the areas of hematological diagnosis and cancer pathology, which are the areas where most significant advances have been made to date. [Image adapted from Y. Park, M. Diez-Silva, G. Popescu, G. Lykotrafitis, W. Choi, M. S. Feld, and S. Suresh, Proc. Natl. Acad. Sci. 105, 13730-13735 (2008).].

[Long-term paratesticular leiomyosarcoma. Conceptual and literature review]

INTRODUCTION

To know the incidence and clinical and pathologic characteristics of the paratesticular leiomyosarcoma (LMS) with the contribution of a case of long evolution, studying the histopathologic criteria that must be valued for this type of tumours.

MATERIAL AND METHODS

A 73-year-old patient includes for study with scrotal tumour present left side for 30 months. Histopathologic and imunohistochemical study is realized. Of equal form there is realized a bibliographical search of this type of tumours and their different subtypes across Medline and of not index-linked search.

RESULTS

Our case is the second of greater evolution of international literature, first in greater of 60 years and one of those of smaller mitotic index (1 x 50 cga). Nevertheless, his atipia, tumorlike necrosis next to 50% of the injury and its pleomorphic properties, as well as his inmunophenotypic characterization corresponds with a well differentiated LMS, degree 1 (French Federation Cancer). We have found only 107 published cases of this type of sarcomas, of them 5 in our country, which gives to a profile of the low incidence of these tumours, that within sarcomas 1% do not reach. We included the clinical and pathologic profile of such.

CONCLUSIONS

The long evolution of a paratesticular tumour and the absence of metastasis does not exclude its malignancy. The low incident of the LMSs in this location, implies that a protocol of actuation validate for such does not exist. We considered of great importance, its creation on the part of urologist, oncologists, radiologists and pathologists like he took control of located in retroperitoneal cavity and deep soft tissues.

[Epididymis trombosed hemangioma in old patient. Presentation of 1 case with conceptual review and of the literature]

INTRODUCTION

Though theoretically in the paratesticular region one can develop any type of benign tumour of soft tissues, they are the lipomas, leiomyomas and adenomatoid tumours the most usual whereas the hemangiomas are less common. We contribute a new case of epididymis intrascrotal hemangioma (HI), valuing the bibliography that allows us to know the incidence and clinic-pathologic characteristics of these tumours.

MATERIAL AND METHOD

A 74-year-old patient includes for study with right scrotal tumour, who is practised orchiectomy. Hystopathologic study is realized. Of equal form there is realized a bibliographical examination of this type of tumours across Medline and of not index-linked search with conceptual review and of the literature.

RESULTS

The injury corresponds with a HI cavernous trombosed of epididymis with testicular parenchyma respected. Your hystopathologic diagnosis does not present problems, whereas the clinical one and ultrasonographic study, reaches the whole spectrum of tumours, benign and malignant of soft tissues. The number of intrascrotal hemangiomas of epididymis described in the literature is very limited.

CONCLUSIONS

The scrotal tumours are necessary a preoperatory clinical and sonographic study completely, in spite of the fact that they are diagnosed the majority after your surgical removal. The complex system of the tissues on the zone paratesticular implies that the differential enclosed diagnosis does not allow to differentiate, malignant tumours of benign. The low incident of many of these masses has determined the mistake of standardized protocols for your diagnosis but also for their unified treatment.

High Proliferative Activity Excludes Dermatofibroma: Report of the Utility of MIB-1 in the Differential Diagnosis of Selected Fibrohistiocytic Tumors

Context.—Dermatofibroma is a benign fibrohistiocytic tumor composed of a mixture of fibroblastic and histiocytic cells. The diagnosis of this tumor is generally uncomplicated; however, rare variants may be difficult to distinguish from malignant fibrohistiocytic tumors. Deep penetrating dermatofibroma may be difficult to distinguish from dermatofibrosarcoma protuberans, and pseudosarcomatous dermatofibroma and dermatofibroma with monster giant cells share morphologic similarities with malignant fibrous histiocytoma and atypical fibroxanthoma.

Objective.—To find an immunohistochemical marker or markers that differentiate between fibrohistiocytic lesions of skin.

Design.—We evaluated the immunophenotypic characteristics of 83 fibrohistiocytic tumors (36 typical dermatofibromas, 16 cases of dermatofibrosarcoma protuberans, 16 malignant fibrous histiocytomas, and 15 atypical fibroxanthomas) using antibodies against MIB-1 (Ki-67), factor XIIIa, CD34 (HPCA-1), HHF35 (muscle-specific actin), 1A4 (smooth muscle actin), cytokeratin (AE1/AE3, CAM 5.2, and 34βE12), S100 protein, and desmin.

Results.—A high proliferative index detected by MIB-1 staining excluded the possibility of dermatofibroma and was diagnostically useful in separating this entity from dermatofibrosarcoma protuberans, malignant fibrous histiocytoma, and atypical fibroxanthoma. A low proliferative index, however, could not differentiate dermatofibroma from dermatofibrosarcoma protuberans. Factor XIIIa reactivity was not helpful for the diagnosis of dermatofibroma, whereas CD34 reactivity was statistically significant in the diagnosis of dermatofibrosarcoma protuberans. The sensitivity of these 2 markers is low and therefore of questionable practical diagnostic value.

Conclusion.—Evaluation of the proliferative index may further assist in distinguishing dermatofibroma from dermatofibrosarcoma protuberans, atypical fibroxanthoma, and malignant fibrous histiocytoma.

Cultured human fibroblasts in agarose gel as a multi-functional control for immunohistochemistry. Standardization Of Ki67 (MIB1) assessment in routinely processed urinary bladder carcinoma tissue

Immunohistochemistry (IHC) in clinical practice is hampered by lack of standardization and by subjectivity in interpretation and quantitation. This study aimed to develop a control system for IHC in routinely fixed and histoprocessed tissues. Such a system should be easy to handle in clinical practice and should reflect variations in fixation time, section thickness, section storage conditions, and staining protocols. In addition, in image analysis quantitation of immunostained tissues, when using classifiers computed on IHC-control images, the control system should be very stable. Cultured human fibroblasts were suspended in agarose, transferred into a length of tubing and stored at 4 degrees C. Three pieces of the cellgel control were separately fixed, histoprocessed, and paraffin-embedded as external controls. One piece was prepared together with each of 18 bladder carcinoma biopsies as internal controls. Slides with sections from the biopsy and all types of cellgel controls were stored at different temperatures and then stained using three different IHC protocols. The fibroblasts were homogeneously distributed in the agarose gel. Variation in section thickness did not influence immunostaining as evaluated by the MIB1 labelling index (MIB1 LI). The external controls decreased notably in MIB1 LI with increased fixation time. This was not seen in the 18 internal controls that were each fixed with a fresh biopsy. However, section storage and immunostaining conditions influenced the MIB1 expression equally in all control types and to a similar degree to the biopsies. Furthermore, colour-based image analysis quantitation of MIB1 LI in biopsies proved stable and independent of the control type used to compute the classifier.

Undifferentiated tumors: an immunohistochemical analysis on biopsies

Immunohistochemical staining was performed on 145 biopsies with a diagnosis of undifferentiated or poorly differentiated tumor in order to classify them into lymphoid, epithelial, or mesenchymal in origin. It was possible to arrive at a histogenetic diagnosis on immunostaining in 85.5% of cases. Immunostaining confirmed the diagnosis in 32.4% and contributed to diagnosis in 53.1%. Malignant lymphoma was the most common diagnosis (35.9%), followed by carcinoma (23.4%). A panel of antibodies consisting of anti-common leucocyte antigen (LCA), anti-epithelial membrane antigen (EMA), anti-cytokeratin (CK), anti-low to intermediate molecular weight cytokeratin (CAM 5.2), anti-S-100 protein (S-100), and anti-vimentin (VM) may resolve, to a large extent, some of the common diagnostic problems.

Expression of lectin-specific cellular glycoconjugates during oral carcinogenesis

The binding pattern of two lectins, concanavalin A (ConA) and peanut agglutin (PNA), in various phases of tumour progression in the oral epithelium was studied. These included non-dysplastic, dysplastic and neoplastic lesions as well as normal tissue. ConA and PNA showed intense staining in the basement membrane of all types of lesions. Little difference was observed in the staining patterns between different stages of oral carcinogenesis, either with ConA or PNA. ConA showed mild cytoplasmic and membrane staining in all types of lesions while PNA showed moderate to intense staining in both the cytoplasm and membrane of lower-layer cells in all histological groups. The present study therefore shows that these lectins have limited value in the elucidation of oral carcinogenesis and are of insignificant diagnostic value.

Immunohistochemistry with keratin, vimentin, desmin, and alpha-smooth muscle actin monoclonal antibodies in canine mammary gland: malignant mammary tumours

Ten malignant canine mammary gland tumours and five metastases from three of these tumours were studied immunohistochemically with monoclonal antibodies (MoAbs) directed against different human keratin types (K), alpha-smooth muscle actin, vimentin, and desmin. In all tumours the neoplastic epithelium was rather homogeneously labelled with the keratin MoAbs RCK 102 (K 5 and 8) and CAM 5.2 (K 8). The adenocarcinomas (n = 5), the solid carcinomas (n = 2), and the carcinosarcoma (n = 1) showed heterogeneous labelling with the MoAbs specific for luminal cell antigens in the normal canine mammary gland, i.e., K 18, K 7 and K 19 MoAbs. These cells were also immunoreactive with K 4 and K 10 MoAbs. The spindle cell carcinomas (n = 2), however, did not react with these MoAbs. All tumours except one adenocarcinoma were characterized by the absence of immunoreactive labelling with the alpha-smooth muscle actin MoAb. In the solid carcinomas this was associated with the absence of labelling with one or both basal cell specific keratin MoAbs, i.e., 8.7 (K 14 and 17) and RCK 107 (K 14), respectively. In contrast, the other malignant tumours showed marked labelling of neoplastic epithelium with these MoAbs. Another remarkable finding was the labelling of a limited to moderate number of neoplastic epithelial cells with the vimentin MoAb. The presence of such labelling patterns in canine mammary gland tumours may be indicative of malignancy. Metastatic tumour tissues had a labelling pattern largely similar to that of the primary tumour, although also loss of reactivity for some keratin MoAbs was seen.

Immunohistochemistry in tumour diagnosis

Immunohistochemistry has become an everyday tool in diagnostic pathology to increase the accuracy in tumour typing. The most important recent developments include availability of antibodies to leukocyte CD-antigens to nearly comprehensive lymphoma typing in paraffin sections, use of certain leukocyte antigens in typing of solid tumours, e.g. neoplastic endothelial cells (CD31 and CD34) and neural and neuroendocrine cells (CD56, CD57). Also, antibodies selective to individual keratin polypeptides promise to be helpful in the subtyping of carcinomas. Antibodies to nuclear proliferation antigens have already proven helpful in the characterization of tumour cell proliferation. Technical optimization, using enzymatic and non-enzymatic antigen retrieval modalities, is also important.

Chondroblastoma of bone. A clinical, radiological, light and immunohistochemical study

The clinical and morphological findings of 53 chondroblastomas in the files of the Bone Tumour Registry of Westphalia are presented. The mean age of all patients was 19.2 years. The male-to-female ratio was 1.5:1. Forty-two of the tumours (79.8%) were located in the long tubular bones and short tubular bones of the hands and were closely related to the growth plate. Six cases (11.3%) were found in the flat bones, 4 cases (7.5%) in the tarsal bones and 1 case (1.9%) in the craniofacial bones. The characteristic radiological feature of 44 investigated lesions was a mostly eccentric radiolucency with a geographic pattern of bone destruction and matrix calcifications. Periosteal reaction was evident in 9% of the cases. Most tumours demonstrate the typical morphological features of chondroblastoma, but 3 cases resembled a giant cell tumour. In 2 cases a haemangiopericytoma-like growth pattern was observed. Nine of the tumours had an aneurysmal bone cyst-like component. Vascular invasion was seen in 1 case. Immunohistochemically most cells in 30 of the cases and fetal chondroblasts in 3 cases were strongly positive with vimentin and S-100 protein. Collagen type II was positive in the chondroid matrix of the tumours and in fetal cartilage tissue; collagen type VI was present focally around individual tumour cells and was always seen in the chondroid matrix of the lesions and in fetal cartilage. These findings support the cartilaginous nature of these tumours. In paraffin sections, 46.6% of the cases revealed a distinct positive reaction of some tumour cells with the monoclonal cytokeratin antibody KL1 (molecular weight 55-57 kDa). Only 4 of them demonstrated a coexpression with the other monoclonal cytokeratin antibody CK (clone MNF 116, molecular weight 45-56.5 kDa). In paraffin sections all fetal chondroblasts were negative with both cytokeratin antibodies. Frozen sections of 3 tumours showed a strong positive reaction with both cytokeratin antibodies in many chondroblasts, indicating an "aberrant" cytokeratin expression. Osteoclast-like giant cells stained positive with leucocyte-common antigen (LCA) and with the macrophage-associated antibody KP1, but were negative with the other macrophage-associated antibody MAC 387. Recurrence rate was 10.7%. The clinical course of all tumours was benign.

The stem cells of the liver ? a selective review

The current status of the much-debated question of the still-hypothetical stem cells of the liver is reviewed, with an emphasis on their role in hepatocarcinogenesis. The widely held view of the primacy of the hepatocyte, notably of the mononuclear diploid type, in this process--the "hepatocytic theory"--has been compared with variants of the "stem cell hypothesis" based on the "non-parenchymal epithelial cells" of the liver--the "oval" or biliary ductular cells, the "nondescript periductular" cells and the "primitive" bipotential epithelial cells. An attempt has been made to concentrate mainly on the more recent publications, in an effort to balance the conflicting opinions expressed by comparing results obtained by the newer procedures currently in use. Despite some interesting and relevant findings it appears that the evidence in favour of the stem-cell hypothesis is still circumstantial and that the hepatocytic theory has not been invalidated. Presumably the question of the hepatic stem cells will be answered when the riddle of hepatocarcinogenesis has been solved.

Immunohistochemistry of primitive neuroectodermal tumors in infants with special emphasis on cytokeratin expression

Eleven primitive neuroectodermal tumor (PNET) biopsies from infants under the age of 3 years were studied for the presence of various differentiation markers for neuroectodermal stem cells. Special emphasis was placed on the expression of cytokeratin proteins. The tumor cells expressed different cytokeratin proteins (CK8, CK13, CK18, CK19, KL1, AE1/AE3, MNF16) in 3 of 11 cases. These cases were furthermore characterized by a strong expression of glial fibrillary acidic protein, S-100 protein and vimentin. Vimentin and cytokeratin proteins were co-expressed; cross-reactivity between these two intermediate filaments could be excluded by immunoblotting. It is noteworthy that the three positive tumors were all from infants in their 1st year. We assume that PNETs in early infancy are characterized by a particularly wide range of differentiation patterns. The presence of cytokeratin proteins in these cases seems to be associated with the expression of vimentin and must be regarded as an indicator of an early developmental stage of the tumor cells.