Peptide vaccinations elicited strong immune responses that were reboosted by anti-PD1 therapy in a patient with myxofibrosarcoma.

Peptide-based immunotherapy does not usually elicit strong immunological and clinical responses in patients with end-stage cancer, including sarcoma. Here we report a myxofibrosarcoma patient who showed a strong clinical response to peptide vaccinations and whose immune responses were reboosted by anti-PD1 therapy combined with peptide vaccinations. The 46-year-old man showed a strong response to the peptide vaccinations (papillomavirus binding factor peptide, survivin-2B peptide, incomplete Freund's adjuvant, and polyethylene glycol-conjugated interferon-alpha 2a) and subsequent wide necrosis and massive infiltration of CD8+ T cells in a recurrent tumor. The patient's immune responses weakened after surgical resection; however, they were reboosted following the administration of nivolumab combined with peptide vaccinations. Thus, anti-PD1 therapy combined with peptide vaccinations might be beneficial, as suggested by the observations in this sarcoma patient.

Experimental models of pancreatic cancer desmoplasia.

Desmoplasia is a fibro-inflammatory process and a well-established feature of pancreatic cancer. A key contributor to pancreatic cancer desmoplasia is the pancreatic stellate cell. Various in vitro and in vivo methods have emerged for the isolation, characterization, and use of pancreatic stellate cells in models of cancer-associated fibrosis. In addition to cell culture models, genetically engineered animal models have been established that spontaneously develop pancreatic cancer with desmoplasia. These animal models are currently being used for the study of pancreatic cancer pathogenesis and for evaluating therapeutics against pancreatic cancer. Here, we review various in vitro and in vivo models that are being used or have the potential to be used to study desmoplasia in pancreatic cancer.

Dendritic fibromyxolipoma: a variant of spindle cell lipoma with extensive myxoid change, with cytogenetic evidence.

Dendritic fibromyxolipoma (DFML), a rare, recently described distinct benign soft tissue tumor, has many clinicopathological features reminiscent of spindle cell lipoma and solitary fibrous tumor with myxoid change. It is distinguished histologically from both entities by the presence of spindle and stellate cells with dendritic cytoplasmic prolongations, prominent myxoid stroma with abundant keloidal collagen and occasional small plexiform vascular proliferation. We describe a case of histologically confirmed DFML of the left shoulder in a 67-year-old male, in which subsequent cytogenetic analysis revealed deletion involving 13q14.3 region in all the tumor cells, typically detected in spindle cell lipoma. In the presence of many clinicopathological similarities between DFML and spindle cell lipoma including chromosomal abnormalities, we postulate that DFML is merely a rare variant of spindle cell lipoma with extensive myxoid degeneration, and may not be considered as a separate entity. The possible differential diagnosis and their distinguishing features are briefly discussed.

Superficial acral fibromyxoma: a clinicopathological and immunohistochemical analysis of 12 cases of a distinctive soft tissue tumor with a predilection for the fingers and toes.

AIM: Superficial acral fibromyxoma (SAFM) is a rare soft tissue tumor, recently delineated and documentated as a separate entity. We report 12 cases of SAFM observed in our department from June 2004 to June 2010 and highlight pathological features and differential diagnosis. METHODS: Radiographic examination of the affected digit was performed in all patients. All the tumors were surgically excised under local anesthesia. Follow-up was made every 6-8 months for a maximum period of five years. RESULTS: The patients consisted of 8 men and 4 women, age range 28-76 years (mean 51), presenting with a solitary mass or nodule located in the toes and fingers. Histologically the lesions were well circumscribed dermal nodules composed of stellate and spindle cells, arranged in a myxoid matrix. Very low grade atypia and a few mitotic figures were found in only one case. Neoplastic cells showed immunoreactivity for CD34 (12 patients). In contrast focally positive or negative staining was shown for the epithelial membrane antigen (EMA) and CD 99. Actin, S100 protein, HMB45 and cytokeratin were negative. In three cases marked hyperkeratosis and acanthosis of the epidermis was present. Pathological analysis confirmed the diagnosis of superficial acral fibromyxoma. No recurrences were observed even in a long term, 2-5 year follow-up. CONCLUSION: Complete surgical excision of the tumors and a careful follow-up is suggested, despite the benign course previously reported.

Superficial acral fibromyxoma: a clinicopathological study of new 41 cases from the U.K.: should myxoma (NOS) and fibroma (NOS) continue as part of 21st-century reporting?

BACKGROUND: Superficial acral fibromyxoma (SAF) remains poorly recognized by general pathologists and dermatopathologists, partly attributable to its relatively uncommon occurrence and recent documentation. OBJECTIVES: To examine a series of SAF and document the U.K. experience with this new entity. METHODS: We reviewed 771 tumours reported between 1970 and 2006 in seven different U.K. hospitals and coded as myxoma, not otherwise specified (NOS), fibroma (NOS) or dermatofibroma (NOS) presenting at acral sites. Forty-one cases of SAF were studied. RESULTS: The patients comprised 27 men and 14 women, age range 19-91 years (mean 50, median 47), presenting with a solitary mass or nodule with a mean size of 1.92 cm. The common clinical sites were the toes (n=29) and fingers (n=11) as well as the palm (n=1), with more than 75% of cases close to or involving the nail bed. All cases presented with a painless mass except for four cases where pain was the presenting complaint. A history of trauma was reported in only two cases. Histologically, all cases presented as proliferation of spindle-shaped and/or stellate cells with a storiform and fascicular pattern embedded in a fibromyxoid/collagenous stroma with conspicuous mast cells. Multinucleated cells were observed (n=22), increased number of blood vessels in the stroma and extravasation of red blood cells (n=4). The characteristic immunophenotype was CD34+, CD99+/-, epithelial membrane antigen+ focally/-, S100-, desmin-, smooth muscle actin-, HMB45- and cytokeratin-. CONCLUSIONS: We describe a large series of 41 cases of SAF showing that it is a distinct entity with typical clinical, histological and immunohistochemical features. Follow-up was available only in 12 patients, precluding a firm comment on recurrence. However, complete excision and follow-up review is recommended.

Immunohistology of malignant rabbit fibroma virus--a comparative study with rabbit myxoma virus.

Malignant rabbit fibroma virus (MV) causes a syndrome that consists of disseminated malignant tumors and immunosuppression complicated by severe Pasteurella multocida infection and death. Tissues from rabbits given MV and rabbit myxoma virus were examined by direct immunofluorescence with the use of antibody against virus antigens. Primary and metastatic tumors caused by MV and rabbit myxoma virus were composed of soft tissue cells containing virus antigens. Skin appendages and epidermis overlying the respective tumors showed scant MV but abundant myxoma virus antigen. Both viruses were present systemically in the reticuloendothelial system. Epithelial cells from the liver, kidney, and lung of myxoma virus-infected rabbits contained virus, whereas in MV tumor-bearing rabbits, these cells were uninvolved. However, nasal mucosal and conjunctival epithelia, the locations of Pasteurella infection, showed squamous metaplasia and contained large amounts of MV and myxoma antigens. By analogy to other respiratory tract pathogens, these epithelial changes were probably etiologically significant for development of pasteurellosis in rabbits bearing virus-induced tumors. Thus by immunopathologic as well as clinical examination, MV produces a syndrome distinct from that seen with rabbit myxoma virus. MV induced severe immunosuppression despite T-lymphocyte hyperplasia in the lymphoid tissues observed. The combination of a systemic virus infection, epithelial alterations that impaired clearance mechanisms, and immunologic dysfunction is likely to contribute to the inability of rabbits given MV to survive their gram-negative infection.

CD-34 is expressed by a distinctive cell population in peripheral nerve, nerve sheath tumors, and related lesions.

The pattern of CD-34 antigen (human progenitor cell antigen) immunoreactivity was studied within normal nerve, and a variety of nerve sheath and neuroectodermal tumors. Besides normal nerves, 111 soft tissue tumors were studied, including 17 neurofibromas, 10 neurilemomas, 12 malignant peripheral nerve sheath tumors, 1 melanocytic schwannoma, 21 fibroblastic lesions, 31 fibrohistiocytic lesions, seven neuroectodermal lesions, and 10 miscellaneous tumors. CD-34-positive dendritic cells were consistently identified within the endoneurium of normal nerve, all neurofibromas, dermatofibrosarcomas, and Antoni B (but not Antoni A) areas of neurilemomas. CD-34 was not expressed in the majority (eight of 10 cases) of malignant peripheral nerve sheath tumors. CD-34 was also lacking in all fibroblastic lesions (nodular fasciitis, fibromatosis, keloid, fibrosarcoma) and in neuroectodermal tumors that are not generally considered to show true nerve sheath differentiation (neurotropic melanoma, clear cell sarcoma, neuroepithelioma). We conclude that CD-34 (or a closely related epitope) defines a normally occurring nerve sheath cell that appears to be cytologically and immunophenotypically distinct from a fibroblast and conventional Schwann cell. The antigen can also be localized to benign nerve sheath tumors, but tends to be lost in malignant ones. The consistent presence of CD-34 within all 13 cases of dermatofibrosarcoma protuberans can be used as evidence in support of the view that these lesions are variants of nerve sheath tumors, and distinct from benign fibrous histiocytomas which consistently lack the antigen. Finally, expression of CD-34 by one of three giant cell fibroblastomas reinforces the close relationship between this tumor and dermatofibrosarcoma protuberans.

Cellular differentiation in ovarian sex-cord-stromal and germ-cell tumors studied with antibodies to intermediate-filament proteins.

Seventy ovarian sex-cord-stromal and germ-cell tumors were immunohistochemically studied for the presence of intermediate-filament proteins of different types used as markers for cellular differentiation. Cells of ovarian granulosa-cell tumors constantly expressed vimentin and appeared to lack cytokeratin. Two tumors previously classified as granulosa-cell tumors were reclassified as poorly differentiated "common" epithelial tumors based on their cytokeratin positivity, vimentin negativity, and morphologic features. Dysgerminomas and Leydig-cell tumors showed only vimentin positivity. Tubular structures in androblastomas, which are considered to represent Sertoli-cell differentiation, were cytokeratin positive, and thus differed from the majority of normal Sertoli cells that are known to express vimentin and not cytokeratin. Embryonal carcinomas, choriocarcinomas, and endodermal sinus tumors showed cytokeratin positivity in the neoplastic cells whereas vimentin was observed in the stromal cells. In immature teratomas, epithelial differentiation was demonstrated with cytokeratin antibodies, and neural and glial differentiation was also frequently demonstrated by immunostaining with antibodies to neurofilaments and glial fibrillary acidic protein. The results show that antibodies to intermediate filaments can be used in the differential diagnosis between ovarian epithelial and nonepithelial tumors, and they provide a very accurate additional method to characterize the cellular differentiation of ovarian neoplasms.

Characterization of breast carcinomas by two monoclonal antibodies distinguishing myoepithelial from luminal epithelial cells.

Two monoclonal antibodies, KA 1 and KA 4, raised against human epidermis, were biochemically and immunologically characterized and were shown to react with specific cytokeratin polypeptides. On frozen sections of human mammary gland, these antibodies distinguish between myoepithelial and luminal epithelial cells. We present evidence that in these cells KA 1 antibody recognized cytokeratin 5 and KA 4 antibody cytokeratin 19. In normal mammary tissue, KA 4 antibody invariably reacted with the epithelial cells lining the lumina of acini, ductules, ducts, and sinus. In contrast, KA 1 antibody decorated only the myoepithelial and basal epithelial cells of acini, ducts, and sinus. In ductules, however, KA 1 also stained the luminal cells. All 73 invasive lobular and ductal carcinomas studied reacted with KA 4 antibody; five of these were also positive, apparently in the same tumor cells, with KA 1. The tumor cells of in situ carcinomas were also stained in a homogeneous pattern with KA 4 antibody; KA 1 antibody reacted only with the surrounding myoepithelium. In epithelial hyperplasias, the proliferating cells were decorated by KA 1 and KA 4 antibodies in a heterogeneous pattern. Other antibodies were used for comparison. The results are discussed with respect to epithelial differentiation and pathogenesis and to the application of such antibodies for immunohistodiagnosis of mammary lesions.

Superficial collagenous fibroma: immunohistochemical, ultrastructural, and flow cytometric study of three cases, including one pemphigus vulgaris patient with a dermal mass.

Collagenous fibroma (desmoplastic fibroblastoma) is an extremely rare benign soft tissue tumor of fibroblastic origin. The majority of reported cases have been located in the deep subcutis, fascia, aponeurosis, or skeletal muscle of the extremities, limb girdles, or head and neck regions. There has been no mention of underlying diseases in patients who developed this tumor. We here report an additional three cases of superficial collagenous fibroma, one of which was a dermal lesion occurring in the abdomen of a 26-year-old male patient with a 5-year history of pemphigus vulgaris prior to development of the tumor. To the best of our knowledge, an association between collagenous fibroma and pemphigus vulgaris has not previously been reported. The remaining two tumors were located in the superficial subcutaneous tissue of the infrascapular area and right foot, respectively. There was no tumor recurrence or metastasis during follow up of 18, 25, and 47 months, respectively. All three tumors were well-circumscribed and unencapsulated without infiltrating borders. Histologically, the common denominator of all three cases was paucicellular proliferation of spindle or stellate fibroblasts enmeshed within an extensively collagenous background. Immunohistochemically, there was diffuse strong staining for vimentin and intense focal reaction for smooth muscle actin in two tumors tested. Electron microscopy revealed features consistent with a fibroblastic or myofibroblastic lineage. Flow cytometry in two cases demonstrated a diploid DNA content with low S-phase fractions, which correlated with minimal MIB-1 nuclear labeling (less than 1%) and benign behavior of this entity.

Biological characterization of human bone tumors. VIII. Expression of HLA-DR antigens in bone tumors and tumor-like lesions.

A total of 45 cases of bone tumors and tumor-like lesions were studied in order to determine the expression of an HLA-DR antigen by the monoclonal antibody 910-D-7, and its possible correlation with histology, using the indirect immunoperoxidase method on frozen sections. The pattern of antigen expression was nearly constant for the individual cell types, though varying in intensity, and did not depend on the biological behavior of the respective lesions. No clear correlation could be established between antigen expression and cell maturation. Although the biological significance of antigen expression in these tumors is not yet understood, it is clear that here, too, the mere presence of an HLA-DR antigen cannot be interpreted as a sign of malignant transformation.

Pseudosarcomatous fibromyxoid tumor of the urinary bladder.

The light-microscopic, immunohistochemical, and ultrastructural features of two examples of a pseudosarcomatous fibromyxoid tumor of the urinary bladder are reported. Both patients were women, 56 and 52 years old. Gross hematuria was the chief complaint and occurred for two days and two weeks, respectively, before presentation. Cystoscopy revealed a 2 X 1 X 1 cm mass located at the dome in case 1 and a 4 X 3 X 3 cm mass at the left posterior lateral wall in case 2. Microscopically, the lesions were composed of spindle, plump, or stellated fibroblast-like cells embedded in myxoid stroma with little collagen; mitotic figures were about 2 per 10 high-power fields, and both cases showed encroachment of the superficial muscle bundles. Because of bizarre spindle cell proliferation, occasional mitoses, and invasion to the underlying muscle, these lesions were initially diagnosed as embryonal rhabdomyosarcoma. However, follow-up examination disclosed the benign nature of these lesions. There was no previous instrumentation or surgery on the genitourinary tract. Immunohistochemical and ultrastructural studies revealed the fibroblastic-myofibroblastic nature of these lesions. These cases illustrate that clinicopathologic correlation is essential to define certain pseudosarcomatous lesions.

Inflammatory pseudotumour of the liver.

Five cases of inflammatory pseudotumour of the liver are reported and compared with seven individual previously published case reports. Clinical presentation was variable but often comprised low grade intermittent fever, vague abdominal symptoms, and a history of weight loss. Leucocytosis, raised erythrocyte sedimentation rate, and polyclonal hyperglobulinaemia were also sometimes detected. All five cases in the present series were considered to be clinically malignant; and in two the histological diagnosis was also that of malignancy. The lesion is clearly inflammatory and reactive, but the aetiology remains unknown.

Laryngeal papillomatosis: immunologic and viral basis for therapy.

The distressing nature of laryngeal papillomatosis and lack of clinical progress in its treatment are reviewed. Presently accepted and investigative methods of therapy are reviewed with special attention being given to immune therapy. Support for the concept of a viral etiology is discussed and other etiologic agents considered. Known and possibly significant roles of wart virus antibodies are discussed and the importance of complex interplay between maternal and fetal immune systems explored as a possible explanation for some puzzling aspects of laryngeal papillomatosis. Finally, a proposed experimental design is outlined, the purpose of which is to provide a useful animal model to investigate immune changes in laryngeal papillomatosis, as well as effects of surgical or medical therapy.

Recurrent respiratory papillomatosis: management with the CO2 laser.

Recurrent respiratory papillomatosis is most common in childhood but it affects all age groups; it represents a diathesis of the aerodigestive tract so that lesions amy develop at various sites - the nares, lips, pharynx, nasopharynx, larynx, tracheobronchial tree, approximately one-third of patients for one year or more; since relapses amy occasionally occur 2 to 20 years later, cure can never be assumed. At the present time, management is directed towards total ablation of all visble papilloma consistent with preservation of the airway and voice; reduction of the tumor burden to minimal proportions is thought to allow the maximum opportunity for remission. As the host-papilloma relationship is unraveled, it may be possible in the future to provoke an immune response so that remissions can be predicted and produced consistently.

Inflammatory pseudotumor of the liver: report of two cases.

Inflammatory pseudotumor of the liver is a very rare lesion. Herein we describe two cases of this entity which occurred in two women aged 22 and 49 years, respectively. Both cases were considered to be clinically malignant and only the histopathologic examination revealed the non-neoplastic nature of the disease. Ultrastructural and immunohistochemical studies further supported the evidence of a reactive disease.

Papillomavirus genomes in experimentally induced fibromas in white-tailed deer.

Cutaneous fibromas of white-tailed deer were transmitted successfully to 5 young deer. Serial biopsy specimens of the induced lesions were analyzed for white-tailed deer papillomavirus, using Southern blot hybridization. Viral genomes were found in all specimens taken 1 to 7 weeks after inoculation and, in some cases, from specimens of the inoculation site obtained later. Viral DNA was found before histologic evidence of fibroblast proliferation and persisted in low copy number, compared with viral DNA of naturally developing fibromas.