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(NOTE: It seems that with each addition to this site, there is some progress in my attitude; with this progress, the SECTIONS seem less like a lark. In accepting the utility of a web site, I have put aside the options for a colored background in favor of this transparent background.
The material I am dealing with is dated. I particularly like the material of this section; there is no mention of immunohistochemistry. Immunohistochemistry is leading us to a state in which morphology is molded to accommodate a variety of reactions. Myofibroblasts and myopericytes are, in part, the product of this molding of cells to fit immunohistochemical profiles.)
Definition of Types of Analyses (cont.)
Critical analysis: As an alternative to pattern analysis, subtle histologic features of real images are to be sought out; they then are to be correlated with relevant virtual images (if any are accessible to the observer). The subsequent interpretations should then be recorded. With detailed analysis of both concordant, and discordant virtual and real images, the resultant classifications are likely to be complex; they are likely to embrace manifold biologic phenomena.
Integrated analysis: Ideally, both patterns and details are integrated in arriving at a histologic diagnosis. In the face of the additive effects - when both options are utilized and correlated - it is fruitless to proclaim that one, or the other, form of analysis is superior, and to then promulgate guidelines in support of such a proclamation.
Failed analysis: If detailed real images cannot be matched with appropriate virtual images, a final diagnosis is likely to be arbitrary; any proffered therapeutic guidelines for the clinicians will likely prove to be aberrations. In the face of what would appear to be compromised, or weak histologic interpretations, clinicians may search for more definitive opinions. Utilizing the same material, other consultants may be able to offer a “definitive,” although not necessarily correct, diagnosis. The general tone of their report may denigrate the value of any earlier, but less “definitive” reports. Egos are inseparable from the interpretative process, especially in consultative work. Egos are also indispensible in the machinations during malpractice proceedings; they, being the embodiment of a new set of biased virtual images, are manipulable by opposing attorneys (who have their own systems of logic, “forensics”).
Virtual image and the interpretation of evolutionary changes: The interpretation of variable histologic patterns is facilitated by an appreciation of the manner in which histologic patterns, and stages in the life histories of disease are interrelated. In the histologic interpretation of neoplasms, certain stages of progression, or regression may be characterized by non-diagnostic real images. With particular combinations of non-diagnostic real images, an evolutionary sequence, leading from equivocal real images to significant virtual images may be structured. The combination of images may then provide insights into paradoxical, clinical and histologic relationships. The uninitiated, in their evaluations of histologic patterns (as manifested in the life histories of disease), may find few common features at the extremes of the spectra of neoplastic phenomena.
Structuring of virtual images: Real images, clinical and laboratory data, knowledge of the life histories of disease processes, prognostic parameters, and intuition are all incorporated in the structuring of virtual images. For each observer, the resulting amalgam is individualized. Peculiarities of individual observers are manifested in each observer’s relative rate of success following the integration of real and virtual images (success being measured by concordance between the implications of diagnoses, and course of disease). Dissent is common at all levels of expertise in histologic interpretations. The peculiarities of individuals provide an explanation for the frequent expressions of dissent among experts.
The linguistic expression of virtual images: In the conduct of human intercourse, communication is a requisite. To have utility, virtual images, having been elicited with all their whimsical qualities, must be amalgamated with real images, and then must be summarily molded into words: they must be structured in the guise of linguistic symbols. In the exercise of the assigned linguistic forms, the intent and charge of the original real, and the virtual images are often distorted. As a result, a proper way by which images can be accurately portrayed may be lost. At times, each of us, with no stigma of negligence, loses the proper way.
Prolonged and extended manipulations of both virtual images, and the related linguistic symbols - if independent of the restraints provided by repeated referrals to respective real images - can lead to transmogrifications not only of the virtual images, but also of their intent; the manipulations of both virtual images, and their respective language can become independent of the original amalgam of real and virtual images. These acts constitute phenomena that are commonly encountered in our exchanges; they have been popularized as “controversies,” and as such are often self-defeating.
In controversies, labels, not images, become the focus of discussion; reason is replaced by logic. In these exhibitions and expostulations, the labels become charged with the forces of the debators’ personalities. Unfortunately, audiences tend to lose sight of the vacuousness inherent in an exercise of linguistic labels that is independent of the checks and balances provided by the interplay of real and virtual images. In most “ controversies,” real images are inconsequential; manipulation of linguistic symbols, and sounds become the measure of “truth.”
The capriciousness of intellectually elicited virtual images
Under the stresses of a heavy workload, or the weariness of exhaustion, virtual images, if volitionally elicited and not spontaneous, may be incongruous with real images. They become both plastic, and capricious. In this manner, the final diagnosis may be misleading. The discrepancies may become obvious to the respective pathologist, if, with a refreshed perspective, he later has occasion to review the sections, and to compare the real images, and his new virtual images with his original confabulations.
Linguistic labels as limiters in the manipulation of virtual images: Labels tend to stifle the evocation of virtual images. An impetuous, rather than thoughtful, characterization of real images is a common practice. If, in this practice, patterns are too soon labeled, and a “diagnosis” (i.e., an assignment of linguistic symbols to virtual and real images) provided, only a limited selection of virtual images will have been mobilized. Designations, too quickly assigned, compromise the interpretative processes.
Malignant Melanoma (an Historical Perspective)
Before the 1950’s, malignant melanoma was almost universally fatal. Precursors had not been defined, and most melanomas were diagnosed and treated late in their evolution; mostly, the diagnosis of an early melanoma was fortuitous. A review of histologic material from this period provides ready documentation of this uniform neglect; melanomas were large and bulky (1 cm or more in diameter), and metastases were common at the time of the initial presentation of the patient. Surgical procedures were radical; for melanomas of the extremities, hindquarter and forequarter amputations were routine.
In the late 1950’s and the 1960’s, attempts to define early stages in the evolution of melanomas were embodied in the concepts of “atypical melanocytic hyperplasia,” ‘melanoma-in-situ,” “incipient melanoma,” and “superficial melanoma.” In addition, the concept of “precancerous melanosis” must be creditied as both an appreciation for, and documentation of, a precursor of melanoma.
In the late 1960’s, contributions by Clark and his co-workers provided insights into a spectrum of melanocytic neoplasia. In these contributions, the relationships between melanoma cells, and anatomic boundaries were utilized as a basis for the delineation of histologic microstages. Five levels, each related to specific anatomic boundaries, or compartments, were defined but no single compartment, to which all the neoplastic cells were confined, was offered as providing a distinction, more or less, between melanoma and some, until then, undefined precursor. Later, level I was eliminated as a meaningful option, and lesions which were confined to this level were not included in the category of “melanoma.” One alternative was to characterize lesions at level I as “atypical melanocytic hyperplasia.” Still later, the concept of “melanoma-in-situ” was vigouously promoted (in large part to the discredit of “atypical melanocytic hyperplasia,” and with an exposition of the susceptibility of language [as symbols of real and virtual images] to perverse manipulations).
In Clark’s later modifications of his schemes, lesions at level II, with a requisite high degree of atypia, were assigned to the category of superficial spreading melanoma (SSM). Superficial spreading melanoma at level I was not an option. In contrast, actinically induced lesions at level I were characterized as lentigo maligna (LM). A degree of specificity thus was assigned to an “in situ” lesion in a setting of actinic damage. A specific precursor was given recognition, and assigned a distinctive designation (i.e., identified as something other than “atypical melanocytic hyperplasia” or “melanoma-in-situ”) (the designation, precancerous melanosis antedated that of lentigo maligna, and had equal utility as an identifier of patterns in a precursor lesion of a specific form of melanoma). In a similar setting, similar lesions at level II, with no restrictions on degree of atypia, were characterized as lentigo maligna melanoma (LMM) at level II. A specific precursor had evolved into a specific variant of melanoma by the simple identification of a dermal component; the number and distribution of nests in the dermis did not impact on the decision to classify such lesions as melanomas. Melanoma of the in situ type, and those at level II are “melanomas” simply by the expediencies of linguistic accommodations.
In Clark’s scheme, in the definition of SSM and LMM, two components, radial and vertical growth, were defined; the former was identified as a remnant of a precursor lesion (most often characterized as the radial component even in the absence of vertical growth). In this approach, a precursor was not assigned a specific designation. To assign a lesion to a specific category of SSM, a requisite degree of atypia was required in the remnant of the precursor. A requisite degree of cytologic atypia was not a requirement in the characterization of lentigo maligna, but was imposed on the precursor in the definition of SSM. In practice, this requirement for a certain degree of dysplasia in SSM is not rigidly observed.
With the definition of the “premalignant melanocytic dysplasias,” as manifested in the dysplastic nevus syndrome (B-K mole syndrome or familial melanoma syndrome), the dysplasias were found to share many features with those of the radial growth components of fully evolved melanomas, particularly SSM, but including lentigo maligna melanoma. Most of these common features were also common to “atypical melanocytic hyperplasias” and “melanoma-in-situ.” These common attributes notwithstanding, the terminology initially proposed by Clark, and others remains the standard: one might have anticipated that the role of dysplasias in the evolution of common melanomas would have been accommodated by modifications in our terminology (e.g., the premalignant dysplasias of the dysplastic nevus syndrome at particular stages are indistinguishable from any remnant of the precursor of SSM).
Superficial spreading melanoma (SSM) is associated with dysplasia-like patterns in the radial growth component, but a reguisite degree of atypia is required in its epidermal component. Whatever the limitations of the assigned linguistic symbols, superficial spreading melanoma is the common melanoma arising in the setting of the common premalignant melanocytic dysplasia (as manifested in the dysplastic nevus syndrome). SSM is melanoma arising from high grade dysplasia, but is neoplastically linked in a sequence to lower grades of dysplasia. The designation, SSM, retains validity, even though currently the cytologic spectrum of the radial growth component (i.e., the remnant of the dysplastic precursor) tends to be broader than the restricted spectrum proposed by Clark. In characterizing a lesion as SSM, recognition is given to the fact that most dysplasias will have progressed to a high grade (i.e., high nuclear grade) by the time the dermal component is sufficiently developed to be characterized as vertical growth (the special care in the wording of this definition should be appreciated; the definition does not require that the patterns of the radial growth component, and those of the vertical growth component show cytologic congruence).
Lentigo maligna melanoma (LMM) remains the accepted designation for melanoma arising in an actinic lentiginous dysplasia (lentigo maligna). Acral lentiginous melanoma is an accepted designation for certain melanoma of the plantar and palmar surfaces. Similar lesions arise on the squamous mucosae, and in the subungual sites. Patterns, basically similar to those of SSM but differing mainly in cytologic features, degrees of cytologic atypia, and patterns of epidermal response, may be encountered in both actinic, and acral settings. On occasion, in both the actinic and acral settings, the patterns of SSM, as a regional variation in radial growth, are manifested in a background of patterns more in keeping with either lentigo maligna melanoma, or acral lentiginous melanoma.
One approach to this overlap in patterns and syndromes would be to characterize SSM as an expression of a common final pathway that is accessible to a variety of premalignant dysplasias, including actinic and acral variants; this approach is embodied in the concept of minimal deviation melanoma. In the concept of minimal deviation melanoma (MDM), the designation, radial growth component, only has application to a lesion in vertical growth; in the absence of vertical growth, the pattern of a radial growth component, regardless of degree of atypia, is simply referred to as a dysplasia, and is qualified as to degree of atypia.
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