Application of immunohistochemistry to soft tissue neoplasms

Modulation of the intestinal mucosal and cell-mediated response against natural helminth infection in the African catfish Clarias gariepinus

Fish gut is a versatile organ serving as the primary pathway for invasion by pathogens, particularly parasites, playing a crucial role in modulating the intestinal adaptive immune response. This study aimed to investigate the cellular-mediated reaction, mucosal acidity, and the expression of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and CD68 in the intestines of catfish, Clarias gariepinus, naturally infected with helminths. Forty catfish were collected from the Nile River and examined for intestinal parasites. The intestinal tissues of the control and infected fish were fixed for histochemical and immunohistochemical studies. Two groups of helminths were found: cestodes Tetracampos ciliotheca and Polyonchobothrium clarias, and nematodes Paracamallanus cyathopharynx, with a prevalence rate of 63.63%, 18.0%, and 18.0%, respectively. Our results showed that the infected fish had a statistically significant rise in the activity of immune cells, including mast cells, eosinophil granular cells, and dendritic cells. This correlated with upregulation in the expressions of PCNA, VEGF, and CD68. Histochemical analyses demonstrated a marked increase in acidic mucus production, Sudan black B, and bromophenol mercury blue. This study enriches our understanding of the evolution of vertebrate immunity in combating intestinal parasitic infections and the host's adaptive responses.

Unusual Presentation of Tonsillar Spindle Cell Neoplasm: A Case Report

Spindle cell neoplasm of the tonsil are rare (Minami et al. in Am J Otolaryngol 29(2):123-125, 2008) and can be difficult to diagnose due to their non-specific clinical presentation and histological characteristics (Su et al. in J Chin Med Assoc 69(10):478-483, 2006). Differential diagnoses include lymphoma and squamous cell carcinoma (Hyams in Clin Otolaryngol Allied Sci 3(2):117-126, 1978). Oropharyngeal spindle cell neoplasms were more likely to occur in the tongue base and tonsil (58%) (Gerry et al. in Ann Otol Rhinol Laryngol 123(8):576-583, 2014). In this article, we report a case of tonsillar spindle cell neoplasm which is extremely rare.

Undifferentiated pleomorphic sarcoma in a white-eared opossum (Didelphisalbiventris)

We report a case of high-grade undifferentiated pleomorphic sarcoma in a free-living white-eared opossum (Didelphis albiventris) in Central Brazil. Grossly, it appeared as a soft yellow mass, approximately 8 cm in diameter, with an irregular, adherent and ulcerated surface, which extended from the proximal epiphysis of the femur to the proximal third of the tibia and fibula. The mass invaded the medullary cavity and had a necrotic centre. Multiple nodular metastases (0.5-1.5 cm) were present in the liver, lungs and spleen. Histologically, the neoplasm was characterized by pleomorphic cells with indistinct boundaries, many multinucleated cells, necrosis and tissue invasion. There was intense cytoplasmic immunolabelling of neoplastic cells for vimentin and moderate cytoplasmic and nuclear labelling for human muscle actin, human smooth muscle actin and lysozyme. Immunolabelling for Iba1, CD18, CD1A, cytokeratin AE1/AE3, glial fibrillary acidic protein and desmin was negative. To our knowledge, this is the first report of an undifferentiated pleomorphic sarcoma in this species.

Primary Hepatic Angiosarcoma Presenting As Cryptogenic Cirrhosis

Primary hepatic angiosarcoma (PHA) is an exceedingly rare and aggressive neoplasm of mesenchymal origin. PHA makes a very small portion of primary liver tumors and conveys a poor prognosis. Symptomatology can be vague and often mimics primary hepatocellular carcinoma upon presentation. Diagnosis requires careful immunohistopathologic confirmation. We present a case of PHA in a patient with abdominal pain and suspected underlying cryptogenic cirrhosis.

Primary Cardiac Angiosarcoma: A Review

Primary cardiac angiosarcoma is a rare and aggressive malignancy originating from the endothelial lining of cardiac blood vessels. This review covers various aspects of the disease, including its pathogenesis, clinical presentation, diagnosis, treatment, and prognosis. The primary characteristic of cardiac angiosarcoma is the rapid growth of abnormal blood vessels that invade the heart muscle, leading to the destruction of healthy tissue. Due to its infiltrative nature and early spread, diagnosing and treating cardiac angiosarcoma present significant challenges. Transesophageal echocardiography (TEE) plays a crucial role in diagnosing cardiac tumors such as angiosarcoma due to its high sensitivity. Additional imaging techniques such as computed tomography (CT) and cardiac magnetic resonance imaging (MRI) help assess tumor anatomy and identify metastases. Histopathological examination and immunohistochemistry are essential for confirming the diagnosis, as they reveal distinct histological features and specific endothelial markers associated with primary cardiac angiosarcoma. Targeted therapies directed at the angiogenic mechanisms and molecular abnormalities hold promise for improving treatment outcomes. Early detection of primary cardiac angiosarcoma remains challenging due to its rarity, and the prognosis is generally poor due to advanced disease at the time of diagnosis. The review emphasizes the importance of a multidisciplinary approach and collaboration among different specialties to optimize the diagnosis, treatment, and follow-up care of patients with primary cardiac angiosarcoma. The ultimate goal is to enhance diagnostic methods and therapeutic approaches by advancing knowledge and promoting further research into this aggressive malignancy.

Primary cardiac epithelioid angiosarcoma: A case report

Primary cardiac angiosarcoma is an extremely rare, high-grade malignancy. Here, we describe the case of a 44-year-old male patient with a heart tumor in the left atrium wall, which caused a large amount of pericardial effusion that invaded the surrounding area and is visible on transthoracic echocardiography, computed tomography, and magnetic resonance imaging. The postoperative histopathological results confirmed this case as a primary cardiac epithelioid angiosarcoma.

Immunohistochemical analysis of von Willebrand factor expression in myocardial tissues from autopsies of patients with ischemic heart disease

von Willebrand factor (VWF) plays a crucial role in hemostasis and thrombosis. VWF is involved in platelet attachment to the subendothelium, serving as a carrier protein for coagulation factor VIII. In this study, myocardial tissues from deceased patients with ischemic heart disease and a mouse model of acute myocardial infarction were subjected to immunohistochemistry to determine VWF expression. We examined 28 neutral formalin-fixed, paraffin-embedded myocardial tissue samples obtained from the autopsies of patients who were diagnosed with ischemic heart disease within 48 h postmortem. Most myocardial cells were negative for VWF, although some cells showed nonspecific positivity. Elevated VWF expression was observed around myocardial cells undergoing remodeling, suggesting that endothelial proliferation occurred at these sites. In contrast, completely fibrotic myocardial foci did not show upregulated VWF expression. Positivity in fibrin deposition and hemorrhagic sites was observed. The same VWF expression characteristics as those observed in the human samples were observed in the mouse model. VWF immunostaining as an endothelial marker may be a useful supplementation to conventional staining techniques that are currently used in the diagnosis of ischemic heart disease in terms of examining the timing of myocardial remodeling in detail and highlighting the remodeling process.

Abdominal wall endometriosis versus desmoid tumor - a challenging differential diagnosis

Aim: Abdominal wall endometriosis (AWE) in young women, with previous gynecological abdominal surgery, is the first condition considered by many practitioners when a tumor in the region of the scar appears. AWE seems to be caused by an iatrogenic transfer of endometrial cells at the level of the scar. The onset of the disease may be late in many cases. Despite the fact that the disease could be totally asymptomatic, there are certain risk factors that can be identified during the anamnesis, such as: heredity, menarche at the age of >14 years, menstrual cycle <27 days, delayed menopause, excessive alcohol and caffeine consumption. Suggestive signs include cyclic or continuous abdominal pain caused by a palpable abdominal wall mass with a maximum tenderness in the region of the surgical scar. The differential diagnosis is complex and rare entities like desmoid tumors (DTs) must be taken into consideration. Desmoid tumor, or the so-called aggressive fibromatosis (AF), is a rare fibroblastic proliferation. This tumor can develop in any muscular aponeurotic structure of the body and is considered benign but with a high recurrence rate. DTs can cause local infiltration, subsequently producing certain levels of deformity and potential obstruction of vital structures and organs. The differential diagnosis is challenging in this situations, the imagery exams are useful, especially in detecting the precise location of the tumor. The histological examination of the tumor can state the final and precise diagnosis.

Fibrosarcoma of anterior abdominal wall: A rare case report

INTRODUCTION

Adult Fibrosarcoma (FS) is very rare and it constitutes approximately 1% of adult sarcomas. It is a malignant or intermediate (rarely metastasizing) tumor, composed of fibroblasts with variable collagen production. Fibrosarcomas usually involve the deep tissues of the extremities, trunk, head and neck. Adult FS usually appears in the fourth to sixth decades of life with a male predominance.

CASE REPORT

A 62 years male patient presented with a large swelling over anterior abdominal wall since 20 years. Physical examination revealed a 15 × 15 cm large lobulated swelling situated over right hypochondrium and extending to epigastrium and right lumbar region. A wide local excision of tumour was done till the posterior rectus sheath. As the skin was involved the tumour was excised along with the skin. A large defect of around 20 × 20 cm was created in anterior abdominal wall. Mesh was placed over the defect and defect was closed by rhomboid flap reconstruction.

DISCUSSION

The World Health Organization (2002) defined fibrosarcoma as a malignant tumor, composed of fibroblasts with variable collagen and, in classical cases, it has a herring bone pattern on light microscopy. Fibrosarcomas typically present as a non-specific soft tissue mass, sometime in a previously irradiated field or rarely in association with implanted foreign material. Fibrosarcomas metastasize to lungs and bone, especially the axial skeleton, and rarely to lymph nodes.

CONCLUSION

Although rare, fibrosarcoma should also be kept as a differential diagnosis in a case of anterior abdominal wall lumps.

The diagnostic challenges of patients with carcinoma of unknown primary

INTRODUCTION

Cancer of unknown primary (CUP) is a disease entity encompassing heterogeneous malignancies without a clinically-detectable anatomical primary. It is usually a poor prognosis malignancy with dismal prognosis where molecular and genetic testing were expected to be a major breakthrough.

AREAS COVERED

In this review, we provide an overview of the advances in the understanding of the carcinogenesis, biology, diagnosis and treatment of patients with CUP. This review focuses on the advantages and inconveniences of immunohistochemistry and CUP classifiers in assessing the progress in the management of CUP.

EXPERT OPINION

CUP classifiers were expected to gradually replace the classical multistep approach in identifying the culprit tumors to guide site-specific therapy. Immunohistochemistry staining led to the prediction of a single tissue of origin in 10.8-51%. CUP classifiers identified the primary site in 61-89% of these cases and were concordant with immunohistochemistry in 57.1-100%. Immunohistochemistry is cheap, fast and broadly available whereas CUP classifiers are less widely available and have not been validated in randomized control trials. The diagnostic recommendations consist of a standard pathology evaluation based on morphology and algorithmic immunohistochemistry assessment. Physicians should weigh in the input of the CUP classifier to the clinical picture and pathology investigations before performing additional investigations.

Immunohistochemical Analysis of CD99 and PAX8 in a Series of 15 Molecularly Confirmed Cases of Ewing Sarcoma

Ewing sarcomas are an uncommon group of malignant neoplasms. A multidisciplinary approach is highly recommended to reach a correct diagnosis, considering the clinical, radiological, and histopathological aspects. Since in up to 90% of cases, the translocation t (11; 22) (q24; q12) occurs resulting in a chimeric fusion transcript EWSR1-FLI-1. The pathologist has several tools in addition to conventional techniques (hematoxylin and eosin), such as immunohistochemistry, which plays a very important role in the differential diagnosis. We present a series of 15 cases of molecularly confirmed ES, in which we found a sensitivity of 100% for CD99 and 80% for PAX8 by immunohistochemistry. This indicates a high sensitivity; however, it is known that both CD99 and PAX8 are also expressed in other tumours. Therefore, molecular confirmation should be performed in all cases.

[Carcinoma with unknown primary site: Morphological diagnosis]

Carcinoma with unknown primary site (CUPs) is a group of malignant tumors, the first manifestation of which is metastatic dissemination. A primary tumor cannot be usually identified by a physical examination of patients with CUPs; a postmortem study plays a significant role in the diagnosis of the origin of metastasis. The paper gives the data available in the literature data on the postmortem diagnosis of CUPs and considers the morphological characteristics of metastases and the possibilities of immunohistochemical diagnosis and a molecular genetic method in the search for a primary focus.

Extraskeletal myxoid chondrosarcoma of the leg in a child: A case report

RATIONALE

Extraskeletal myxoid chondrosarcoma is a slow-growing soft tissue tumor of adults with a propensity for local recurrence and eventual metastasis. Only 17 pediatric and adolescent cases have been reported.

PATIENT CONCERNS

Here we present an 11-year-old boy with a 3-year history of a slowly growing painless left leg mass. Magnetic resonance imaging of the lesion revealed a subfascial well-circumscribed lesion with intramuscular extension in the medial gastrocnemius muscle of the left leg.

DIAGNOSES

He underwent wide local excision of the mass and the histomorphological and immunohistochemical findings were consistent with extraskeletal myxoid chondrosarcoma.

INTERVENTIONS

Possible radiotherapy was the further management plan.

OUTCOMES

He was in good condition with no evidence of recurrence at 6 months postsurgery.

LESSONS

Although pediatric cases of extraskeletal myxoid chondrosarcoma were reported to be aggressive, the tumor in this case demonstrated indolent behavior. Furthermore, the tumor in this case showed primitive round cell foci which adds to a previous study that especially reported this morphology in pediatric cases.

Regression of primary cardiac angiosarcoma and metastatic nodules following propranolol as a single agent treatment

Angiosarcoma is the most common malignant cardiac tumor. Cardiac angiosarcoma is a highly lethal neoplasm that is largely resistant to conventional anti-cancer therapy. Mean survival of patients with cardiac angiosarcoma is only 4 months, and almost all patients will succumb to the disease within 1 year. The beta blocker propranolol is an emerging therapy against angiosarcoma. When combined with conventional therapies, propranolol increases progression free and overall survival in patients with this tumor type. It is currently unknown if propranolol is capable of showing anti-cancer efficacy as a single agent therapy. We report a case of a 61 year old woman diagnosed with primary cardiac angiosarcoma and liver and lung metastases. This patient chose to decline conventional therapy, and instead was prescribed the beta blocker propranolol as a single agent treatment. After 12 months, the mediastinal mass substantially debulked and decreased in size, and the metastatic nodules stabilized or resolved with no evidence of hyper-metabolic activity on PET-CT. This is the first reported data showing long term efficacy of the beta blocker propranolol as a single agent therapy against angiosarcoma.

Solitary Intra-Osseous Myofibroma of the Jaw: A Case Report and Review of Literature

Myofibroma is a rare benign spindle cell neoplasm in children that usually affects both soft tissue and bone in the head and neck region. Approximately one third of these cases are seen within jaw bones as solitary lesions. Solitary intra-osseous myofibroma of the jaw bone shares its clinical, radiographic and histological features with other spindle cell tumors. The rarity of this lesion can make diagnosis difficult for clinicians and pathologists. We report a case of a solitary intra-osseous myofibroma in the mandible of a nine-year-old child.

Effects of ICOS+ T cell depletion via afucosylated monoclonal antibody MEDI-570 on pregnant cynomolgus monkeys and the developing offspring

MEDI-570 is a fully human afucosylated monoclonal antibody (MAb) against Inducible T-cell costimulator (ICOS), highly expressed on CD4+ T follicular helper (T_FH) cells. Effects of MEDI-570 were evaluated in an enhanced pre-postnatal development toxicity (ePPND) study in cynomolgus monkeys. Administration to pregnant monkeys did not cause any abortifacient effects. Changes in hematology and peripheral blood T lymphocyte subsets in maternal animals and infants and the attenuated infant IgG immune response to keyhole limpet hemocyanin (KLH) were attributed to MEDI-570 pharmacology. Adverse findings included aggressive fibromatosis in one dam and two infant losses in the high dose group with anatomic pathology findings suggestive of atypical lymphoid hyperplasia. The margin of safety relative to the no observed adverse effect level (NOAEL) for the highest planned clinical dose in the Phase 1a study was 7. This study suggests that women of child bearing potential employ effective methods of contraception while being treated with MEDI-570.

Unclassified sarcomas: a study to improve classification in a cohort of Golden Retriever dogs

Morphologically, canine soft-tissue sarcomas (STSs) resemble human STSs. In humans, proper classification of STSs is considered essential to improve insight in the biology of these tumors, and to optimize diagnosis and therapy. To date, there is a paucity of data published on the significance of detailed classification of STSs in the dog. We revised a cohort (n = 110) of proliferative lesions obtained from a study in Golden Retrievers that were considered "soft tissue sarcoma, not otherwise specified or of uncertain subtype" in order to optimize the diagnoses of these lesions. The criteria according to the veterinary WHO classification, recent veterinary literature, and the WHO classification for humans were applied. Revision was initially based on morphologic characteristics of hematoxylin and eosin-stained histologic sections of the neoplasms. If considered necessary (n = 76), additional immunohistochemistry was applied to aid characterization. The diagnosis of STS was confirmed in 75 neoplasms (68%). Of this group, diagnosis of a specific subtype of the STSs was possible in 58 neoplasms. Seven neoplasms had morphologic characteristics that were suggestive for sarcoma subtypes only described in the WHO classification for humans. Seventeen neoplasms remained "unclassified STSs." Thirty-one lesions (28%) were diagnosed "neoplasm, not being STS." Four lesions (4%) were considered nonneoplastic. Because incorrect classification of a tumor could lead to inappropriate therapeutic intervention and prognostication, the results of our study clearly illustrate the importance of revision and further diagnosis of "unclassified STSs" in dogs.

Certainty of S100 from Physiology to Pathology

S100 exists in wide variety of tissues and cell types, originally isolated from brain tissue and they are of low molecular weight proteins. S100 is evenly distributed in cytoplasm and also in nucleoplasm and is involved in both intercellular and extracellular functions. S100 protein is generally expressed in normal and also in pathological conditions. In current review, we discuss: a) update nomenclature of the various S100 proteins, b) expression of S100 in oral diseases (different soft tissue tumors, odontogenic cyst and tumor) for diagnostic value and also to know their histogenesis, c) role of S100 and RAGE receptor in oral squamous cell carcinoma.

[The role of pathology in the diagnostics of CUP syndrome]

Cancers of unknown primary (CUP) origin account for 2-3 % of all malignancies in Germany and represent a heterogeneous, often aggressive and clinically challenging group of tumors with early metastatic dissemination for which a standardized diagnostic work-up initially fails to identify the primary site of origin at the time of diagnosis. This article reviews the options and challenges of tissue-based conventional as well as molecular diagnostic procedures to categorize this heterogeneous group of neoplasms. The role of pathology in the diagnostics of CUP syndrome is described as part of a multidisciplinary effort involving oncologists, surgeons and radiologists with the ultimate goal of assisting clinical reasoning and decision-making.

The "myofibroblast" that is omnipresent in pathology and key to the EMT concepts does not actually exist, since normal fibroblasts contain stress fibril organelles (SMA bundles with dense bodies) variably detected by TEM and IHC: conclusions by a diagnostic pathologist with decades of ultrastructural experience

The so-called "enigmatic" unique "myofibroblast" has been erroneously substituted for virtually all things fibroblastic in soft tissue pathology and believed to be the ultimate fibrogenic cell. It is also internationally considered to be the mesenchymal cell in un-proven post-natal EMT, EMT organ/tissue fibrosis, and the assumption that EMT/MET is key to carcinoma/adenocarcinoma invasion and metastasis. However, no such cell exists, having been mistaken for our normal ubiquitous fibrogenic fibroblasts that contain peripheral bundles of actin (SMA) with dense bodies, i.e. stress fibril (SF) organelles variably detectable by TEM and SMA IHC, depending on the degree of activation. The only detectable features distinguishing what are erroneously believed to be two unique fibrogenic spindle cells are the SF. Is the variable detection of SF/SMA in fibroblastic and non-fibroblastic lesions significant? Carcinosarcomas are not bi-phasic malignancies or proof of EMT/MET. What does it mean that the fibroblasts of so-called "carcinoma-associated fibroblasts (CAF)" are not "myofibroblasts"? The true myofibroblast is the ultrastructurally and functionally unique, terminally-differentiated, pathognomonic cell of physiologic wound-healing, which unfortunately has been confused with the activated fibroblast. This study fails to demonstrate any ultrastructural evidence that either normal epithelial (EMT) or carcinoma/adenocarcinoma cells can undergo reversible transition into mesenchymal cells (EMT/MET) under any circumstances. The SF/SMA-positive fibrogenic cell in organ/tissue fibrosis is the genetically up-regulated, activated fibroblast, which has no relationship to EMT. Are any of the innumerable biochemical factors/elements considered to be associated with this non-existent cell and its related processes related to the activated fibroblast? The conclusions are based on review of every electron micrograph taken during a 40-year career in diagnostic and research ultrastructural pathology, and by confirming that the published TEM figures of so-called "myofibroblasts", are actually of fibroblasts.

Subcutaneous dermatofibroma: a rare case report with review of literature

A purely Sub-cutaneous benign fibrous histiocytoma (BFH; dermatofibroma) is rarely reported, as it is usually a dermally located mesenchymal tumour and in absence of supportive immunohistochemical (IHC) studies, it is often misdiagnosed. We are describing a case of a 19-year-old female who presented to the skin outpatient department with a painful swelling on the medial side of her thigh. Fine needle aspiration (FNA) revealed a sub-cutaneous spindle cell (mesenchymal) lesion which was corroborated on histopathology, with differentials of BFH and dermatofibrosarcoma protruberans (DFSP). BFH constitutes a diagnostic dilemma for both clinicians and pathologists, because the lesions share common clinical symptoms, radiological characteristics and histological features with many varied entities. For its subtyping and confirmation; immunohistochemical (IHC) studies were undertaken. In the present case, positivity of IHC markers, vimentin and smooth muscle actin emphatically proved that BFH arose exclusively from the subcutaneous region, with no dermal origin. Also, a negative CD34 immunostaining, along with low B-cell lymphoma 2 (Bcl-2) expression ruled out DFSP (both are strongly expressed in DFSP), MFH and other malignant mesenchymal lesions. Negative CD 68 staining ruled out giant cell lesions and their congeners. This case is worth reporting, as it not only describes a rare case presentation of BFH, but as it also highlights the importance of IHC, thus helping to comprehensively clinch the diagnosis by systematically ruling out other differentials.

Use of immunohistochemical staining and electron microscopy to aid in diagnosis of soft tissue sarcomas associated with the fetlock joint in two horses

Soft tissue sarcomas of the equine distal limb associated with joints, sheaths, or bursae have rarely been reported. Accurate diagnosis of these tumors is challenging in both human beings and veterinary species. Immunohistochemical staining and transmission electron microscopy have been used in human beings to reduce misdiagnosis. The current report describes 2 mature horses presenting with lameness and swelling associated with the dorsal aspect of the metacarpo(tarso)phalangeal joint. In both cases, surgical excision was performed with subsequent histological analysis of the masses to determine the tissue of origin. In both cases, immunohistochemical staining and transmission electron microscopy aided the definitive diagnosis of fibrosarcoma associated with the fetlock joints of 2 horses.

Primary cardiac angiosarcoma - a review

Primary cardiac neoplasms are extremely rare. Angiosarcoma is the most commonly seen histological subtype and is characterized by its permeating and destructive nature. Unfortunately, primary cardiac angiosarcoma is often overlooked as an initial diagnosis because of its rarity. Since the time it was first identified in 1934, little progress has been made in improving survival outcome. Complete or partial surgical resection is still the best option for palliation, with little hope for cure. Improvements have been made in the ability to view and distinguish tumors. Echocardiography is one of the most useful diagnostic tools because of its high sensitivity; therefore, CT and MR images are often used to detect sites of metastatic disease. Immunohistochemistry staining can also be employed as an adjunctive diagnostic tool. CD31, CD34, FLI-1, and von Willebrand factor are the most commonly used markers in detecting tumors of endothelial origin. However, due to the vast heterogeneity within a tumor, immunohistochemistry staining can be quite variable. Surgical resection remains the standard modality of treatment. Primary cardiac angiosarcoma is largely resistant to chemotherapy and/or radiation. However, the exact benefit and its place in a multimodality treatment regimen are still under investigation.

Multiple low-grade sarcomas of fibroblastic type in the setting of HIV and acquired epidermodysplasia verruciformis

A 46-year-old white male with a history of HIV (CD4 245), acquired epidermodysplasia verruciformis, anal carcinoma in situ, hepatitis B and C presented with 3 asymptomatic, nontender, firm pink/skin-colored nodules involving the arm, left lateral leg, and right third finger. One year later, he developed a similar lesion on his right medial lower leg. Excisional biopsy of one of the lesions showed an atypical spindle cell neoplasm of the dermis compatible with a low-grade sarcoma of fibroblastic origin. Testing for human herpes virus-8, 23 human papillomavirus types, Epstein-Barr virus, and FUS fusion protein were negative. The patient underwent diagnostic imaging with computed tomography scans of the chest, abdomen, and pelvis along with positron emission tomography scan to ensure that there was no other occult primary tumor, all of which were negative. The lesions were excised and have not recurred with 3 years of follow-up. The best histopathologic term for these lesions is multiple low-grade sarcomas of fibroblastic phenotype. They have been proven to be nonaggressive, with little or no metastatic potential. This is a neoplastic process that has not been well defined in the literature. To our knowledge, there are no previous reports of these lesions occurring in multiple sites or in an HIV-positive patient.

Transgelin is a novel marker of smooth muscle differentiation that improves diagnostic accuracy of leiomyosarcomas: a comparative immunohistochemical reappraisal of myogenic markers in 900 soft tissue tumors

Immunohistochemical use of myogenic markers serves to define smooth or skeletal muscle differentiation in soft tissue tumors. Establishing smooth muscle differentiation in malignant lesions can be challenging in some cases. We immunohistochemically examined 900 soft tissue tumors selected from the French Sarcoma Group's archived tissue collection, which contains a large number of leiomyosarcomas. The four most widely used smooth muscle diagnostic markers were evaluated (smooth muscle actin, desmin, h-caldesmon and calponin), and compared with a novel marker, transgelin. The diagnostic performance of each marker was statistically assessed in terms of sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (A), in leiomyosarcomas versus all other sarcomas including gastrointestinal stromal tumors (GIST), and second in leiomyosarcomas versus specific tumor types. In leiomyosarcomas versus all other sarcomas including GIST, transgelin emerged as the best diagnostic marker (Se: 83%, Sp: 82%, PPV: 67%, NPV: 92%, A: 83%), compared with smooth muscle actin (Se: 75%, Sp: 83, PPV: 66%, NPV: 89%, A: 81%), desmin (Se: 45%, Sp: 88%, PPV: 62%, NPV: 79%, A: 75%), h-caldesmon (Se: 50%, Sp: 90%, PPV: 67%, NPV: 81%, A: 78%) and calponin (Se: 76%, Sp: 70, PPV: 52%, NPV: 87%, A: 71%). In leiomyosarcomas compared with other specific tumor types such as undifferentiated pleomorphic sarcoma and myxofibrosarcoma, the accuracy for transgelin varied from 80 to 87% whereas it was lower for all other markers (between 51 and 80%). These results indicate that transgelin could be used in practice as an additional marker useful for decision making, especially in those tumors with incomplete immunophenotypes.

Adult rhabdomyoma with oncocytic changes affecting the floor of the mouth: optical, immunohistochemical, and ultrastructural study

Adult rhabdomyoma (AR) is an extremely uncommon benign neoplasm with mature skeletal muscle differentiation comprising approximately 2% of muscle tumors, usually affecting the soft tissue of the head and neck. Although histology of AR is characteristic, several differential diagnoses (granular cell tumor, hibernoma, oncocytoma) should be considered, and one needs to be familiar with this rare entity to exclude other neoplastic diseases. We present a case of AR, in a 54-year-old man, affecting the floor of the mouth, and call attention to the oncocytic appearance (including antimitochondrial and peroxiredoxin I immunoreactivity) of this case and its differential diagnosis analyzed at the optical, immunohistochemical, and ultrastructural level, showing the morphological and immunohistochemical features that can be confused with a salivary oncocytoma.

[The use of frozen sections in the handling of soft tissue tumors]

Due to the multiplicity of localizations and entities, handling of soft tissue tumors is a very challenging subject requiring intensive interdisciplinary collaboration. With respect to the use of intraoperative frozen sections, the following facts are of special relevance: 1) the usual criteria for malignancy, such as infiltrative growth and high mitotic rate are only restrictedly applicable to soft tissue tumors. 2) Correct diagnosis of the tumor entity often requires not only the use of immunohistochemistry but also the identification of genetic alterations by the polymerase chain reaction and/or fluorescence in situ hybridization. In many centres, 14G core biopsies taken from different tumor areas represent the preferred method for a diagnostic biopsy. Apart from cryocollection additional frozen section investigations are used especially in case of open biopsies for quality control of the submitted material or in cases of excision biopsies to ascertain a highly probable radiological diagnosis. The use of intraoperative frozen sections to clarify the resection margins is generally undisputed but should definitely be restricted to centres specialized and experienced in the handling of soft tissue tumors.

Oral alveolar rhabdomyosarcoma: a case report with immunohistochemical analysis

Rhabdomyosarcomas are among the most common soft-tissue tumors in children. These tumors are derived from mesenchymal tissue with a tendency toward myogenic differentiation that probably originates from immature and highly invasive satellite cells associated with the embryogenesis of skeletal muscle. Some of these tumors are associated with high rates of recurrence and metastasis. The diagnosis is made by microscopic analysis and auxiliary techniques such as immunohistochemistry, electron microscopy, cytogenetic analysis, and molecular biology. We report a case of 28-year-old man who presented with a painless progressive swelling of gingiva since 3 months, which was gradually increasing in size without any systemic symptoms or signs of any metastatic spread. An incisional biopsy was done and histopathology reported an alveolar variant of rhabdomyosarcoma. Immunohistochemistry with panel of markers was done which showed positivity for CD99, vimentin and negative for desmin and myogenin. So the characteristic immunohistological expression was negative in present case. Hence we conclude that haematoxylin and eosin morphology and ultrastructure are needed to classify rhabdomyosarcoma and immunohistochemistry act only as an auxiliary.

Curent concepts in pathology of soft tissue sarcoma

Soft tissue sarcomas (STS) constitute a heterogeneous category of soft tissue neoplasia composed mostly of uncommon tumors of diverse histology, different biology and varied outcomes. Substantial developments in immunohistochemistry (IHC), cytogenetics and molecular genetics of STS have caused a significant change in the classification and diagnosis of these tumors with a direct implication for clinical management and prognosis. In this review we discuss newer developments impacting diagnosis and prediction.

Biomarkers in the age of omics: time for a systems biology approach

Limitations to biomarker discovery are not only technical or bioinformatic but conceptual as well. In our attempt to offer a solution, we are highlighting three issues that we think are limiting progress in biomarkers discovery. First, the confusion stemming from the imposition of a pathology-type immunohistochemical marker (IHCM) concept on omics data without fully understanding the characteristics and limitations of IHCMs as applied in clinical pathology. Second, the lack of serious consideration for the scope of disease heterogeneity. Third, the refusal of the biomedical community to borrow from other biological disciplines their well established methods for dealing with heterogeneity. Therefore, real progress in biomarker discovery will be attained when we recognize that an omics biomarker cannot be assigned and validated without a priori data modeling and subtyping of the disease itself to reveal the extent of its heterogeneity, and its omics' clonal aberrations (drivers) underlying its subtypes and pathways' diversity. To further support our viewpoints, we are contributing a novel a systems biology method such as parsimony phylogenetic approach for disease modeling prior to biomarker circumscription. As an analytical approach that has been successfully used for a half of a century in other biological disciplines, parsimony phylogenetics simultaneously achieves several objectives: it provides disease modeling in a hierarchical phylogenetic classification, identifies biomarkers as the shared derived expressions or mutations--synapomorphies, constructs the omics profiles of specimens based on the most parsimonious arrangement of their heterogeneous data, and permits network profiling of affected signaling pathways as the biosignature of disease classes.

Diagnosis of metastatic neoplasms: an immunohistochemical approach

CONTEXT

It is important to determine the type and/or site of origin of metastatic tumors for optimal clinical management.

OBJECTIVE

To summarize the use of currently available immunohistochemical markers in the evaluation of metastatic tumors.

DATA SOURCES

Review of relevant literature on immunohistochemical evaluation of tumors and the author's personal experience.

CONCLUSIONS

Immunohistochemistry is an important ancillary technique for evaluation of metastatic tumors and should be used in the context of routine morphology and clinical information. While a single marker may be used to support a known or suspected site of origin, a carefully constructed panel is strongly recommended, particularly for tumors of morphologically uncertain lineage or origin.

Soft tissue tumors: new perspectives on classification and diagnosis

BACKGROUND

In recent years, new tumor entities have been described and previously known tumor types have undergone a reassessment. This article offers an overview of recent developments in the classification and interpretation of soft tissue tumors.

METHODS

Selective review of publications from 1990 until 2008 from the literature database of the Consultation and Referral Center for Soft Tissue Tumors in Jena. The current status of the classification and morphological diagnosis of these tumors is described.

RESULTS

The description of the biological behavior of soft tissue tumors has become more detailed with the introduction of two intermediate categories ("intermediate, locally aggressive" and "intermediate, rarely metastasizing"). There have also been some changes in terminology. Previously established terms such as "malignant fibrous histiocytoma" or "hemangiopericytoma" will be used much less often in future, because these tumor types have been reinterpreted. The WHO recommends that highly differentiated liposarcoma be renamed "atypical lipomatous tumor." Molecular diagnostic techniques have become firmly established as an ancillary diagnostic method. The importance of molecular tumor characterization for individually tailored therapy is already becoming clear.

CONCLUSIONS

Optimal diagnosis is the prerequisite for effective therapy and can be achieved only with state-of-the-art knowledge of the pathology of soft tissue tumors.

Pathologic evaluation of unknown primary cancer

The pathologic approach to metastases of unknown primary cancer (UPC) is stepwise and uses the clinical context, morphology, and, where necessary, immunohistochemistry (IHC). This review covers the initial approach to a UPC biopsy; the diagnosis of malignancy and broad tumor typing into carcinoma, melanoma, lymphoma, or sarcoma; and further subtyping of carcinoma into germ cell (broadly included), squamous, neuroendocrine, and solid organ including liver and renal, and adenocarcinomas. Finally, for adenocarcinoma, the prediction of primary tumor site, including lung, pancreas, stomach, colon, ovary, prostate, and breast, is discussed. For each tumor type, the morphologic features are presented alongside established useful IHC markers, with a description of their staining patterns and common diagnostic dilemmas. Optimal tissue handling and IHC interpretation, quality assurance, and limitations also are discussed. The target readership is oncologists, but other clinicians and trainee pathologists also may find the content of use.