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Paget’s Disease
(Mammary Variant)
Paget’s disease of either the nipple, or of extra-mammary type perhaps is inappropriate as an example of borderline pathology. It is, however, a neoplasm peculiarly expressed as a
glandular process in the setting of a keratinocytic domain. It can be remarkably subtle histologically, subtle to the point of being dismissed as an inflammatory process. In the selected example (S13C18P16-1-6, and S13C19P17-1-3),
the patterns at low magnification resemble those of an acantholytic processs.
Epithelioid Sarcoma
Epithelioid sarcoma (large cell sarcoma of Bliss and Reed) in its classic expression and in a primary setting, is expressed in a spectrum of patterns related to steps of neoplastic
progression. Early on, the lesion may be histologically deceptive.The cytologic features include spindle and round cells in patterns easily accepted as those of fibroblasts and histiocytes. The problems are
compounded by a definite blandness of cytologic features, especially in early stages of neoplastic progressions. The process may be mistaken for an inflammatory process (S13C20P18-1-4). In fact, in the skin, the histologic patterns of isolated “satelllites” may be confused
with the focal lesions of a palisaded granuloma; in such a setting, plump, round cells will be found in palisades about zones of necrosis; in addition, the round cells may be associated with deposits of connective
tissue mucins among individual cells.
Bowenoid Dysplasia
The relationships between genital papilloma virus infection and keratinocytic dysplasias of bowenoid type seem to also implicate the virus in the pathogenesis of bowenoid
keratinocytic dysplasias in extra-genital sites. Clinicians speak of Bowen’s disease and then immediately imbue the designation with all the attributes of carcinoma in situ. Some pathologists speak of bowenoid
keratinocytic dysplasias and then provide for a system in which steps of neoplastic progression terminate in carcinoma in situ (and with further progressions, terminate in invasive carcinoma of a pattern often
characterize as metatypical carcinoma of the skin). In Bernie Ackerman’s world there is no room for keratinocytic dysplasias; from inception, all is carcinomatous. If a pathologist offers the diagnosis of Bowen’s
disease for patterns that are not carcinoma in situ, he will have enabled the clinician; the clinician will assume the role of a surgeon. In like fashion, if all precursor stages are carcinoma in situ, the
clinician will be enabled; the clinician can then treat the lesion in a more aggressive fashion than a diagnosis, based on degrees of dysplasia, might warrant. To not bother with degrees of neoplasia in precursor
lesions does afford a degree of protection from claims of malpractice .
Some examples of condyloma acuminatum show mild degrees of cytologic atypia; they may show changes that would not, by strict criteria, be sufficiently developed to characterize the
lesion as a significant bowenoid dysplasia. In such patterns, there may be only a hint of bowenoid atypia; such lesions might be best characterized as atypical condyloma acuminatum. (S13C21P19-1-3)
Majewski S, Jablonska S: Do epidermodysplasia verruciformis human papillomaviruses contribute to malignant and benign epidermal proliferations? Arch Dermatol 2002;138: 649-54.
Systemic Mast Cell Disease
In the category of mast cell disease, the distinction between neoplasm and hyperplasia often is difficult to define. In infancy and childhood, mast cell disease of the skin usually is
manifested in lesions that have tumoral patterns. The cells tend to be rounded in outline and to show bland, uniform nuclear characteristics. The nuclei of such cells are round, or oval; chromatin is delicate. For
some examples, the nuclei are indented and the cells might be mistaken for histiocytes.
Later in life, many examples of cutaneous mast cell disease do not have tumoral qualities; cells are loosely sprinkled in the adventitia of vessels and skin appendages, and among
collagen bundles of the reticular dermis. In this variation, the cells tend to be dendritic in outlines; they might be characterized as “fixed, or reticular” mast cells.
In systemic mastocytosis, lesions are found in the viscera, skin, and bone; the cells form sheets and, in aggregate, assume tumoral qualities. In the bone marrow, the cells form
sheets with an admixture of eosinophils. The sheets may be associated with lymphoid nodules (S13C22P20-1-4). There
is an association with myelodysplasias. The association offers support for the notion that the mast cell component also is neoplastic.
Stevens EC, Rosenthal NS: Bone marrow mast cell morphologic features and hematopoietiic dyspoiesis in systemic mast cell disease. Am J Clin Pathol 2001; 116: 177-82.
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