Mast cell-dependent effector pathways and cutaneous bullous disorders.
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Antigen-Antibody Reactions↗
Biomedical subjects
M C Mihm
Publications and source records attributed to M C Mihm.
A prognostic model for clinical stage I melanoma of the trunk. Location near the midline is not an independent risk factor for recurrent disease.
Fifteen variables were studied for their usefulness in predicting recurrent disease in 254 patients with clinical stage I melanoma of the trunk. Thickness of the primary tumor correctly predicted outcome with an accuracy of 90 percent or greater in 176 patients with melanoma primaries with a thickness of less than 1.70 mm or 5.5 mm or greater. No other variables significantly increased predictive accuracy over these ranges of thickness. A Cox proportional hazards analysis of the remaining 78 patients with primary tumors 1.70 to 5.49 mm thick demonstrated that the following four variables functioned as independent risk factors for recurrent disease: (1) thickness of the primary tumor (p = 0.0005), (2) mitoses/mm2 greater than 6 (p = 0.006), (3) a nearly absent or minimal lymphocyte response at the base of the tumor (p = 0.009), and (4) location on the upper trunk (p = 0.03). Trunk lesions located near the midline did not have a worse prognosis than more lateral melanomas of similar thickness.
Female↗
Abdominal mass in 43-year-old man.
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Abdominal Neoplasms↗
Melasma: a clinical, light microscopic, ultrastructural, and immunofluorescence study.
Melasma is an acquired brown hypermelanosis of the face. Although it is thought that melasma is associated with multiple etiologic factors (pregnancy, gastric, racial, and endocrine), one of the primary causes of its exacerbation appears to be exposure to sunlight. Three patterns of melasma are recognized clinically: (1) a centrofacial pattern, (2) a malar pattern, and (3) a mandibular pattern. Examination of patients with Wood's light (320--400 nm) is useful in classifying the specific type of melasma in correlation with the localization of pigment granules (melanosomes) in the epidermis and dermis. Four types of melasma are described on the basis of Wood's light examination: (1) an epidermal type, (2) a dermal type, (3) a mixed type, and (4) a fourth type, described in patients of dark complexion, in which the lesions, for lack of contrast, are not discernible on Wood's light examination, perhaps due to the increased number of melanosomes in the normal skin of black individuals. Light, histochemical, and electron microscopic studies revealed an increase in number and activity of type-specific melanocytes which appeared to be engaged in increased formation, melanization, and transfer of pigment granules (melanosomes) to the epidermis as well as to the dermis. The melanocyte seems to undergo a functional alteration brought about by a combination of multiple factors, including persistent sun exposure, hormonal factors, and genetic predisposition.
Adult↗
The human sunburn reaction: histologic and biochemical studies.
The ultraviolet-induced erythema reaction was investigated histologically and biochemically in four subjects, utilizing suction blister aspirates, analyzed for histamine and prostaglandin E2 (PGE2), and Epon-embedded 1-mu skin biopsy sections from control skin and from irradiated skin at intervals for 72 hours after exposure to a Hanovia lamp. Major histologic alterations in the epidermis included dyskeratotic and vacuolated keratinocytes (sunburn cells), and disappearance of Langerhans cells. In the dermis the major changes were vascular, involving both the superficial and deep venular plexuses. Endothelial cell enlargement was first apparent within 30 minutes of irradiation, peaked at 24 hours, and persisted throughout the 72-hour study period. Mast cell degranulation and associated perivenular edema were first apparent at 1 hour and striking at the onset of erythema, 3 to 4 hours postirradiation; edema was absent and mast cells were again normal in number and granule content at 24 hours. Histamine levels rose approximately fourfold above control values immediately after the onset of erythema and returned to baseline within 24 hours. PGE2 levels were statistically elevated even before the onset of erythema and reached approximately 150% of the control value at 24 hours. These data provide the first evidence that histamine may mediate the early phase of the human sunburn reaction and increase our understanding of its complex histologic and biochemical sequelae.
Adult↗
Subcutaneous and skeletal chordomoid nodules in an infant.
Multicentric subcutaneous and skeletal nodules with histologic features of chordoma developed over a period of 3 months in a black infant. Radiolucent intracranial lesions were demonstrated by pneumoencephalogram and computerized tomography scan. The patient received chemotherapy and the nodules regressed. After a follow-up of 7 years, there has been no recurrence of these chordomoid lesions and the child enjoys good health and normal growth and development. In retrospect, these nodules appear to be a benign, self-limited heterotopias and not malignancies. The cells with physaliphorous characteristics may represent unusual differentiation of fibroblasts rather than indicating notochordal origin.
Bone Neoplasms↗
A prognostic model for clinical stage I melanoma of the upper extremity. The importance of anatomic subsites in predicting recurrent disease.
Thirteen variables were studied for their relative usefulness in predicting recurrent disease in 107 patients with clinical Stage I melanoma of the upper extremity. After a mean follow-up period of 54 months, the only patents who have had recurrent disease to date are those who primary lesions were located either on the hand or posterior upper arm. The five-year disease-free survival role for 44 patients with melanoma at these sites was 68%. None of 63 patients with melanoma located on the forearm of anterior upper arm have had recurrent disease (i.e., the five-year, disease-free survival rate was 100% (p = 0.00004), compared with the hand or posterior arm group). A Cox proportional hazards (multivariate) analysis demonstrated that two primary tumor histologic variable, thickness in millimeters and ulceration, interacted to produce the best prognostic model for those 44 patients with melanoma of the hand or posterior upper arm. Twenty-one patients with primary lesions at these sites had primary tumors less than 2.25 mm in thickness and no evidence of ulceration histologically. Their five-year, disease-free survival role was 95%. For the remaining 23 patients with primary tumors on the hand or posterior upper arm who had either histologic evidence of ulceration or primary tumors greater than or equal to 2.25 mm, the five-year disease-free survival rate was 37% (p = 0.002, compared with group nonulcerated, thin lesions). The excellent survival rate for patients with melanomas on the forearm or anterior upper arm was not completely explained by pathologic stage, by primary tumor thickness, or by histologic ulceration of the primary tumor.
Arm↗
Malignant melanoma. Prognostic significance of "microscopic satellites" in the reticular dermis and subcutaneous fat.
A review of the microscope slides of the primary tumors for 596 patients with clinical Stage I melanoma revealed that primary lesions displayed two distinct patterns of invasion: 1) single cell invasion with direct extension of the main body of tumor into the reticular dermis or subcutaneous fat, and 2) invasion with "microscope satellites" (i.e. discrete tumor nests greater than 0.05 mm in diameter, that were separated from the main body of the tumor by normal reticular dermal collagen or subcutaneous fat). The five-year disease free survival rate for 95 patients with "microscopic satellites" was 36% +/- 6%. This is in contrast to a five-year disease free survival rate of 89% +/- 2% for 501 patients without these satellites (p = 4.3 x 10(-29), generalized Wilcoxon test). "Microscopic satellites" (present vs absent) was comparable to histologic ulceration in its additive prognostic effect of tumor thickness (Breslow).
Adipose Tissue↗
Nonepidermal origin of malignant melanoma associated with a giant congenital nevocellular nevus.
We report an adult who developed primary malignant melanoma arising in association with residual nevus cells in the pectoralis muscle under an intact skin graft 13 years following the partial excision of a giant congenital nevocellular nevus (GCNN). The case serves to emphasize the malignant potential of GCNN, for which we estimate a lifetime risk of at least 6.3 percent and an approximate 17-fold risk for melanoma when compared with the general population. This case supports previous observations that melanoma may arise in nonepidermal components of a GCNN and suggests the need to consider excision of the GCNN to muscle fascia or deeper if nevus cells extend beyond this anatomic zone. We estimate the risk of death from general anesthesia during the first year of life to be substantially less than the risk of malignant degeneration during the same time period. The decision to excise the GCNN as soon as the problem is recognized should depend on the general health of the infant and the risk of surgical complications.
Adult↗
Ultrastructural and x-ray microanalytical observations of minocycline-related hyperpigmentation of the skin.
In order to elucidate the nature and distribution of the pigment responsible for the circumscribed blue-black cutaneous hyperpigmentation occurring after administration of minocycline hydrochloride, transmission electron microscopy and energy-dispersive electron x-ray microanalysis were performed on lesional skin. Ultrastructural observations demonstrated electron-dense iron-containing particles either incorporated into a variety of siderosomes, within dermal histiocytes, free within the cytoplasm, or, rarely, scattered among dermal collagen fibers. Electron x-ray microanalysis confirmed iron content present within these particles. Although siderosomal inclusions contained occasional melanosome complexes, the degree of deposition of electron-dense iron-containing particles in dermal histiocytes seemed to be primarily responsible for the blue-black discoloration of the skin. The present study is an investigation of the structure and composition of the pigment responsible for minocycline-related cutaneous hyperpigmentation.
Adolescent↗
T cell subsets and Langerhans cells in lichen planus: in situ characterization using monoclonal antibodies.
Skin biopsies from four patients with lichen planus were studied using monoclonal antibodies directed against T lymphocytes. Anti-TI and anti-T3 antibodies, which react with all peripheral T cells, stained most cells in the dermal infiltrates. The majority of infiltrating cells also stained with anti-T4 and anti-T4b antibodies, which react with helper/inducer cells, whereas a minority of cells stained with anti-T8 antibody, which reacts with cytotoxic/suppressor cells. Surface IgM was not identified on any infiltrating cells, providing evidence against B cell participation. Intraepidermal and dermal cells with long cytoplasmic extensions stained with any anti-T6 antibody in all cases, defining them as Langerhans cells or their precursors. T6-positive cells were seen in greater number than in normal control epidermis and dermis. The results indicate that well-developed lesions of lichen planus are characterized by an influx of helper/inducer T lymphocytes and increased numbers of Langerhans cells. These observations support the contention that cellular immunity is important in the pathogenesis of this disorder.
Antibodies, Monoclonal↗
Encephalocraniocutaneous lipomatosis: a new neurocutaneous syndrome.
Encephalocraniocutaneous lipomatosis is a congenital neurocutaneous disorder with the distinguishing histopathological features of dysgenesis and neoplasia of the adipose tissue. The dominant clinical features of the syndrome include convulsions beginning in infancy, mental retardation, and unilateral cutaneous and ophthalmological lesions with ipsilateral cerebral malformations. A patient with this rare disorder of ectomesodermal dysgenesis has been studied in order to classify clinically and histologically the associated skin lesions. To our knowledge, this is the fourth case of encephalocraniocutaneous lipomatosis reported in the English literature.
Brain↗
The role of histopathology in polymorphous light eruption light testing.
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Adult↗
Carcinosarcoma of the skin. Case report and review.
A carcinosarcoma of the skin in a 74-year-old man is reported. The epithelial element consisted of a highly anaplastic basal cell carcinoma with focal keratinization. The mesenchymal component included elements of fibrosarcoma, chondrosarcoma, osteogenic sarcoma, and synovial sarcoma. This is, to our knowledge, the second reported case of carcinosarcoma arising in the skin.
Aged↗
Cutaneous malignant mixed tumor.
Two cases of cutaneous malignant mixed tumor occurred in a 70-year-old man and a 69-year-old man. Nine previously described patients with cutaneous malignant mixed tumor resembled the two patients in this report, both clinically and histologically. All cases with adequate long-term follow-up evaluations were characterized by recurrence or metastasis. In contrast to benign mixed tumors, these tumors tend to occur on the extremities, are of larger size, and may exhibit rapid growth. Histologically, cellular atypism, increased cellularity, increased mitotic rate, invasion of surrounding tissue, and necrosis may be identified.
Aged↗
Characterization of Langerhans cells by the use of monoclonal antibodies.
Intraepidermal dendritic cells react with the monoclonal antibody, anti-T6, which also reacts with a majority of cortical thymocytes but not with mature T lymphocytes. Application of a four-step peroxidase antiperoxidase technique and immunoelectron microscopy to normal human epidermis demonstrates that T6 antigen is present on the cell surface of Langerhans cells but not on keratinocytes or melanocytes. These data suggest that T6 antigen is an important marker for Langerhans cells.
3,3'-Diaminobenzidine↗
A prognostic model for clinical stage I melanoma of the lower extremity. Location on foot as independent risk factor for recurrent disease.
Thirteen variables were studied to determine their usefulness in predicting recurrent disease in 158 patients with stage I melanoma of the lower extremity. A Cox proportional hazards analysis demonstrated that three variables were independent risk factors for recurrent disease in these patients: (1) thickness, in millimeters, of the primary tumor (P = 0.000009), (2) primary tumor location on the foot (P = 0.0003), and (3) the number of mitoses/mm2 (P = 0.0244). Life-table analyses of patient subgroups defined by different combinations of these three variables demonstrated that thick (greater than or equal to 3.0 mm) melanomas of the foot were associated with recurrent disease much more frequently than tumors of similar thickness located on the thigh or calf. These data provide guidelines that can be used to evaluate results of surgical and/or adjuvant therapy studies for patients with melanoma of the lower extremity.
Foot Diseases↗
Cutaneous vasculitis associated with acute and chronic hepatitis.
We encountered 11 patients who had rashes associated with hepatitis. Five of six acute hepatitis cases, but only one of five chronic hepatitis cases, were related to hepatitis B. Nine of the 11 patients had rash in the absence of clinically overt liver disease. Skin biopsy specimens showed histologic evidence of cutaneous vascular injury; specimens of urticarial and maculopapular rashes, which were seen in this series only with acute hepatitis, showed a primarily lymphocytic venulitis with focal necrosis, while palpable purpura, which was seen in this series only in chronic hepatitis, showed a primarily neutrophilic necrotizing vasculitis involving small vessels. One patient had lichen planus-like lesions. Demonstration of vascular deposits of immunoglobulins, complement, and fibrin in skin, as well as hypocomplementemia, circulating immune complexes, and mixed cryoglobulinemia, in these patients suggests that cutaneous lesions associated with liver disease resulted from immune complex-mediated vascular injury.
Adult↗