Sources/Clones
Dako (MNF 116), Immunotech (MNF 116).
Fixation/Preparation
MNF 116 performs well on formalin-fixed, paraffin-embedded tissue sections. Enzymatic predigestion with proteolytic enzymes such as trypsin and pronase is essential prior to immunodetection, trypsin being superior for MNF 116. This antibody may also be applied to acetone-fixed cryostat sections or fixed-cell smears. Incubation of the primary antibody for 1 h at 37 C yields better immunoreaction.
Background
MNF 116 antibody detects an epitope that is present in a wide range of keratins. These comprise a number of discrete polypeptides, whose molecular weights range from 45 to 56.5 kD. These correspond to Moll's keratin numbers 5, 6, 8, 17 and probably 19 (Moll et al, 1982). The MNF 116 immunogen was derived from a crude extract of splenic cells in a nude mouse engrafted with MCF-7 cells.
In normal tissue, the MNF 116 antibody shows a broad pattern of reactivity with epithelial cells from simple glandular to stratified squamous epithelium. Epithelial cells are labeled irrespective of ectodermal, mesodermal or endodermal origin. However, due to the crossreactivity with the other members of the family of intermediate filaments, this antibody (not unlike other monoclonal anti-keratin antibodies) crossreacts with non-epithelial cells including smooth muscle, dendritic cells in lymph nodes, syncytiotrophoblasts, some cortical neurons and a minority of plasma cells.
Applications
MNF 116 demonstrates excellent immunopositivity with a wide range of benign and malignant epithelial neoplasms. A strong pattern of staining is observed in squamous cell carcinoma (including nasopharyngeal carcinoma), small cell carcinoma, sarcomatoid carcinoma, spindle cell carcinoma, adenocarcinoma and mesotheliomas. In small cell carcinomas, a characteristic paranuclear accentuation pattern of staining has been found to be extremely useful in identifying these neoplasms. Both epithelioid and spindle cell components of mesotheliomas react with this antibody (Miettinen, 1993).
MNF 116 is also useful in confirming the diagnosis in a wide range of soft tissue neoplasms. Monophasic and biphasic synovial sarcomas demonstrate strong positivity (albeit focal in the spindle cells). Vascular neoplasms that react with this broad range cytokeratin antibody include epithelioid hemangioendothelioma (focal), epithelioid angiosarcoma and sinonasal hemangiopericytoma (Mentzel et al, 1997). Epithelioid sarcoma (and the recently described proximal variant) require cytokeratin positivity for diagnosis (Evans & Baer, 1993; Guillou et al, 1997). Other tumors in which cytokeratin positivity is essential for diagnosis include desmoplastic small round cell tumors, chordomas and extrarenal rhabdoid tumors that are consistently positive. Mixed tumors and myoepitheliomas arising in soft tissue were recently described and shown to express pankeratin (Kilpatrick et al, 1997).
Among germ cell tumors, embryonal carcinoma and yolk sac tumors are consistently positive with MNF 116. The following neoplasms may demonstrate aberrant staining with MNF 116. The coexpression of cytokeratins in smooth muscle tumors is well described (Ramackers et al, 1988). Cytokeratin-positive cells have been revealed in plasmacytoma (Wotherspoon et al, 1989). A few primitive neuroectodermal tumors may show focal cytokeratin expression. Rarely, myofibroblasts may demonstrate focal cytokeratin positivity (Jones et al, 1993; Hojo et al, 1995). Quite logically, all of these potential diagnostic pitfalls may clearly be avoided if relevant panels of immunohistochemical antibodies are applied.
Comments
MNF 116 has developed into a first-line antibody in the application of cytokeratins to surgical pathology. It is, however, necessary to be aware of the aberrant immunoreactions in order to avoid misdiagnosis. It is therefore unwise to arrive at a diagnosis based on the assessment of a single cytokeratin marker without the application of other relevant antibodies used in a diagnostic panel to exclude other possibilities. Any epithelial tissue - glandular or squamous is suitable for use as positive control for MNF 116.
References
•Evans HL, Baer SC 1993. Epithelioid sarcoma: a clinicopathologic and prognostic study of 26 cases. Seminars in Diagnostic Pathology 10: 286-291.
•Guillou L, Wadden C, Coindre JM, Krausz T, Fletcher CDM 1997. Proximal-type epithelioid sarcoma: a distinctive aggressive neoplasm showing rhabdoid features. American Journal of Surgical Pathology 21: 130-146.
•Hojo H, Newton WA, Hamondi AB et al 1995. Pseudosarcomatous myofibroblastic tumour of the urinary bladder in children: a study of 11 cases with review of the literature: an Intergroup Rhabdomyosarcoma Study. American Journal of Surgical Pathology 19: 1224-1236.
•Jones EC, Clement PB, Young RE 1993. Inflammatory pseudotumour of the urinary bladder. A clinicopathological, immunohistochemical, ultrastructural and flow cytometric study of 13 cases. American Journal of Surgical Pathology 17: 264-274.
•Kilpatrick SE, Hitchcock MG, Kraus MD, Calonje E, Fletcher CDM 1997. Mixed tumours and myoepitheliomas of soft tissue: a clinicopathologic study of 19 cases with a unifying concept. American Journal of Surgical Pathology 21: 13-22.
•Mentzel T, Beham A, Calonje E et al 1997. Epithelioid haemangioendothelioma of skin and soft tissue: clinicopathologic and immunohistochemical study of 30 cases. American Journal of Surgical Pathology 21: 363-374.
•Miettinen M 1993. Keratin immunohistochemistry: update of applications and pitfalls. In: Rosen PP, Fechner RE. (eds). Pathology Annual, Part 2/vol 28. Appleton & Lange, pp 113-143.
•Moll R, Franke WW, Schiller DL. Geiger B, Krepler R 1982. The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells. Cell 31: 11-24.
•Ramackers FCS, Pruszczynski M, Smedts F 1988. Cytokeratins in smooth muscle cells and smooth muscle tumors. Histopathology 12: 558-561.
•Wotherspoon AC, Norton AJ, Isaacson PG 1989. Immunoreactive cytokeratins in plasmacytomas. Histopathology 14: 141-50.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Dako (MNF 116), Immunotech (MNF 116).
Fixation/Preparation
MNF 116 performs well on formalin-fixed, paraffin-embedded tissue sections. Enzymatic predigestion with proteolytic enzymes such as trypsin and pronase is essential prior to immunodetection, trypsin being superior for MNF 116. This antibody may also be applied to acetone-fixed cryostat sections or fixed-cell smears. Incubation of the primary antibody for 1 h at 37 C yields better immunoreaction.
Background
MNF 116 antibody detects an epitope that is present in a wide range of keratins. These comprise a number of discrete polypeptides, whose molecular weights range from 45 to 56.5 kD. These correspond to Moll's keratin numbers 5, 6, 8, 17 and probably 19 (Moll et al, 1982). The MNF 116 immunogen was derived from a crude extract of splenic cells in a nude mouse engrafted with MCF-7 cells.
In normal tissue, the MNF 116 antibody shows a broad pattern of reactivity with epithelial cells from simple glandular to stratified squamous epithelium. Epithelial cells are labeled irrespective of ectodermal, mesodermal or endodermal origin. However, due to the crossreactivity with the other members of the family of intermediate filaments, this antibody (not unlike other monoclonal anti-keratin antibodies) crossreacts with non-epithelial cells including smooth muscle, dendritic cells in lymph nodes, syncytiotrophoblasts, some cortical neurons and a minority of plasma cells.
Applications
MNF 116 demonstrates excellent immunopositivity with a wide range of benign and malignant epithelial neoplasms. A strong pattern of staining is observed in squamous cell carcinoma (including nasopharyngeal carcinoma), small cell carcinoma, sarcomatoid carcinoma, spindle cell carcinoma, adenocarcinoma and mesotheliomas. In small cell carcinomas, a characteristic paranuclear accentuation pattern of staining has been found to be extremely useful in identifying these neoplasms. Both epithelioid and spindle cell components of mesotheliomas react with this antibody (Miettinen, 1993).
MNF 116 is also useful in confirming the diagnosis in a wide range of soft tissue neoplasms. Monophasic and biphasic synovial sarcomas demonstrate strong positivity (albeit focal in the spindle cells). Vascular neoplasms that react with this broad range cytokeratin antibody include epithelioid hemangioendothelioma (focal), epithelioid angiosarcoma and sinonasal hemangiopericytoma (Mentzel et al, 1997). Epithelioid sarcoma (and the recently described proximal variant) require cytokeratin positivity for diagnosis (Evans & Baer, 1993; Guillou et al, 1997). Other tumors in which cytokeratin positivity is essential for diagnosis include desmoplastic small round cell tumors, chordomas and extrarenal rhabdoid tumors that are consistently positive. Mixed tumors and myoepitheliomas arising in soft tissue were recently described and shown to express pankeratin (Kilpatrick et al, 1997).
Among germ cell tumors, embryonal carcinoma and yolk sac tumors are consistently positive with MNF 116. The following neoplasms may demonstrate aberrant staining with MNF 116. The coexpression of cytokeratins in smooth muscle tumors is well described (Ramackers et al, 1988). Cytokeratin-positive cells have been revealed in plasmacytoma (Wotherspoon et al, 1989). A few primitive neuroectodermal tumors may show focal cytokeratin expression. Rarely, myofibroblasts may demonstrate focal cytokeratin positivity (Jones et al, 1993; Hojo et al, 1995). Quite logically, all of these potential diagnostic pitfalls may clearly be avoided if relevant panels of immunohistochemical antibodies are applied.
Comments
MNF 116 has developed into a first-line antibody in the application of cytokeratins to surgical pathology. It is, however, necessary to be aware of the aberrant immunoreactions in order to avoid misdiagnosis. It is therefore unwise to arrive at a diagnosis based on the assessment of a single cytokeratin marker without the application of other relevant antibodies used in a diagnostic panel to exclude other possibilities. Any epithelial tissue - glandular or squamous is suitable for use as positive control for MNF 116.
References
•Evans HL, Baer SC 1993. Epithelioid sarcoma: a clinicopathologic and prognostic study of 26 cases. Seminars in Diagnostic Pathology 10: 286-291.
•Guillou L, Wadden C, Coindre JM, Krausz T, Fletcher CDM 1997. Proximal-type epithelioid sarcoma: a distinctive aggressive neoplasm showing rhabdoid features. American Journal of Surgical Pathology 21: 130-146.
•Hojo H, Newton WA, Hamondi AB et al 1995. Pseudosarcomatous myofibroblastic tumour of the urinary bladder in children: a study of 11 cases with review of the literature: an Intergroup Rhabdomyosarcoma Study. American Journal of Surgical Pathology 19: 1224-1236.
•Jones EC, Clement PB, Young RE 1993. Inflammatory pseudotumour of the urinary bladder. A clinicopathological, immunohistochemical, ultrastructural and flow cytometric study of 13 cases. American Journal of Surgical Pathology 17: 264-274.
•Kilpatrick SE, Hitchcock MG, Kraus MD, Calonje E, Fletcher CDM 1997. Mixed tumours and myoepitheliomas of soft tissue: a clinicopathologic study of 19 cases with a unifying concept. American Journal of Surgical Pathology 21: 13-22.
•Mentzel T, Beham A, Calonje E et al 1997. Epithelioid haemangioendothelioma of skin and soft tissue: clinicopathologic and immunohistochemical study of 30 cases. American Journal of Surgical Pathology 21: 363-374.
•Miettinen M 1993. Keratin immunohistochemistry: update of applications and pitfalls. In: Rosen PP, Fechner RE. (eds). Pathology Annual, Part 2/vol 28. Appleton & Lange, pp 113-143.
•Moll R, Franke WW, Schiller DL. Geiger B, Krepler R 1982. The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells. Cell 31: 11-24.
•Ramackers FCS, Pruszczynski M, Smedts F 1988. Cytokeratins in smooth muscle cells and smooth muscle tumors. Histopathology 12: 558-561.
•Wotherspoon AC, Norton AJ, Isaacson PG 1989. Immunoreactive cytokeratins in plasmacytomas. Histopathology 14: 141-50.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
