Ocular findings as a presenting sign of hydroa vacciniforme.
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Child↗
Biomedical subjects
T H McCalmont
Publications and source records attributed to T H McCalmont.
Mixed allogeneic chimerism as a reliable model for composite tissue allograft tolerance induction across major and minor histocompatibility barriers.
BACKGROUND: Although prolonged composite tissue allograft (CTA) survival is achievable in animals using immunosuppressive drugs, long-term immunosuppression of CTAs in the clinical setting may be unacceptable for most patients. The purpose of this study was to develop a model for reliable CTA tolerance induction in the adult rat across a major MHC mismatch without the need for long-term immunosuppression. METHODS: Mixed allogeneic chimeras were prepared by using rat strains with strong MHC incompatibility [WF (RT1Au), ACI (RT1Aa)] WF + ACI-->WF, n=23. The bone marrow (BM) of recipient animals was pretreated with low-dose irradiation (500-700 cGy), followed by reconstitution with a mixture of T cell-depleted syngeneic (WF) and allogeneic (ACI) cells. Additionally, the recipient animals received a single dose of anti-lymphocyte serum (10 mg) 5 days before bone marrow transplantation (BMT) and tacrolimus (1 mg/kg/day) from the day before BMT to 10 days post-BMT. Hindlimb transplants were performed 12 months after BMT. Five animals received a limb allograft irradiated (1000 cGy) just before transplantation. Rat chimeras were characterized (percentage of donor cells present within the bloodstream) by flow cytometry at 3 and 12 months after BM reconstitution and after hindlimb transplantation. RESULTS: Peripheral blood lymphocyte chimerism (WF/ACI) remained stable >12 months after BM reconstitution in 18/23 animals. Multi-lineage chimerism of both lymphoid and myeloid lineages was present, suggesting that engraftment of the pluripotent rat stem cell had occurred. In animals with donor chimerism >60% (n=18) no sign of limb rejection was present for the duration of the study. All animals with chimerism <20% (n=5) developed moderate signs of rejection clinically and histologically. Gross motor and sensory reinnervation (weight bearing, toe spread) developed at >60 days in 14/21 rats. Postoperative flow cytometry studies demonstrated stable chimerism in all animals studied (n=10). Five out of five animals with irradiated limb transplants showed no sign of GVHD at >100 days. CONCLUSIONS: Stable mixed allogeneic chimerism can be achieved in a rat hindlimb model of composite tissue allotransplantation. Hindlimb allografts to mixed allogeneic chimeras exhibit prolonged, rejection-free survival. Partial functional return should be expected. The BM transplanted as part of the hindlimb allograft plays a role in the etiology of GVHD. Manipulating that BM before transplantation may influence the incidence of GVHD. This represents the first reliable rat hindlimb model demonstrating rejection-free CTA survival in an adult animal across a major MHC mismatch without the long-term need for immunosuppressive agents.
Animals↗
Rudimentary meningocele: remnant of a neural tube defect?
BACKGROUND: Rudimentary meningocele, a malformation in which meningothelial elements are present in the skin and subcutaneous tissue, has been described in the past under a variety of different terms and has also been referred to as cutaneous meningioma. There has been debate as to whether rudimentary meningocele is an atretic form of meningocele or results from growth of meningeal cells displaced along cutaneous nerves OBJECTIVE: We reviewed the clinical, histological, and immunohistochemical characteristics of rudimentary meningocele in an attempt to assess the most likely pathologic mechanism for it. DESIGN: Retrospective study. SETTING: University hospitals. PATIENTS: Thirteen children with rudimentary meningocele. MAIN OUTCOME MEASURES: Medical records were reviewed and histopathologic examination as well as immunohistochemistry studies were performed for each case. A panel of immunoperoxidase reagents (EMA, CD31, CD34, CD57, S-100, and CAM 5.2) was used to assess lineage and to confirm the meningothelial nature of these lesions. RESULTS: Recent evidence indicating a multisite closure of the neural tube in humans suggests that classic meningocele and rudimentary meningocele are on a continuous spectrum. CONCLUSION: Rudimentary meningocele seems to be a remnant of a neural tube defect in which abnormal attachment of the developing neural tube to skin (comparable to that in classic meningocele) could explain the presence of ectopic meningeal tissue. In the majority of cases, no underlying bony defect or communication to the meninges could be detected. However, in light of the probable pathogenesis, imaging studies to exclude any communication to the central nervous system should precede any invasive evaluation or intervention.
Child↗
Cutaneous manifestations of maternal engraftment in patients with severe combined immunodeficiency: a clinicopathologic study.
SCID is a heterogeneous group of disorders characterized by defective T cell and B cell function. Eczematous and morbilliform eruptions are common, and graft-versus-host disease (GVHD) due to maternal engraftment has been documented. We sought to better characterize SCID-related cutaneous disease observed prior to BMT and to compare the eruption to conventional GVHD. Medical records of 51 patients with SCID treated between 1982 and 1999 were reviewed. Ten of 51 (20%) had rash and evidence of maternal engraftment prior to BMT (study group). Eleven of 51 (22%) had no rash or evidence of engraftment pre-BMT but developed GVHD following transplant (control group). Skin biopsies were available for review for 8/10 of the study group and for 8/11 of the control group. Cutaneous findings consisted of a scaling, erythematous maculopapular eruption spread widely over the trunk and extremities, with near-erythroderma in some patients. Microscopically, biopsies from the study group differed significantly from controls. Key differences included parakeratosis (P < or = 0.01), psoriasiform hyperplasia (P < or = 0.04) and spongiosis (P < or = 0.04). The dermatopathologic findings of transplacental GVHD differ from the pattern of post-transplant GVHD. A 'psoriasiform-lichenoid-spongiotic' pattern with necrotic keratinocytes should trigger consideration of SCID and maternal engraftment in the dermatopathologic evaluation of eruptions of infancy.
Bone Marrow Transplantation↗
A lymphomatoid papule, but not lymphomatoid papulosis!
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Aged↗
Photosensitivity in HIV-infected individuals.
OBJECTIVE: To characterize photosensitivity in HIV-infected individuals using minimal erythema dosage (MED) UVA (ultraviolet A light) and UVB (ultraviolet B light) photoprovocation light testing. DESIGN: Prospective, controlled analytical study. SETTING: University of California, San Francisco, between March 1995 and January 1997. PATIENTS: 13 HIV-seropositive patients with clinical and pathological features consistent with photodermatitis, 13 HIV-seropositive patients with biopsy-proven eosinophilic foliculitis (EF), and 10 HIV-seropositive patients with CD4 (T helper cell) count below 200 cells/uL and no history of photosensitivity or EF. INTERVENTION: Each patient underwent MED testing for UVB. All 13 patients with suspected photodermatitis underwent full photochallenge testing with UVA and UVB for up to 10 consecutive week days. RESULTS: Mean MED to UVB in patients with clinical photosensitivity and EF was lower (p = 0.004 and p = 0.022 respectively) than that of patients without a clinical history of photodermatitis. There were no significant differences in mean CD4 count or Fitzpatrick skin type. Positive photochallenge tests (papular changes at site of provocative light testing) to UVB (9 of 13 patients) were much more common than reactions to UVA (3 of 13 patients) in the photodermatitis group. All patients with clinically active photodermatitis developed papular changes at the site of UVB photochallenge testing, but only 1 of 5 patients with photodermatitis in remission developed papular changes with UVB photochallenge testing. Seven of the 13 patients with photodermatitis had Native American ancestry. Photosensitive patients were commonly taking trimethoprim-sulfamethoxazole (TMP-SMX), but no more commonly than EF or control patients. CONCLUSIONS: Photosensitivity in HIV-infected individuals appears to be a manifestation of advanced disease. Most patients are sensitive to UVB. The most severely affected individuals are both UVB and UVA sensitive, and may show reactions to visible light. A significant Native American ancestry may be a risk factor for development of photodermatitis in patients with advanced HIV disease. Finally, patients with eosinophilic folliculitis may be subclinically photosensitive.
Adult↗
Imipramine-induced hyperpigmentation: four cases and a review of the literature.
BACKGROUND: Hyperpigmentation is a side effect of several medications, including amiodarone, bleomycin, chlorpromazine, and minocycline. OBJECTIVE: The purpose of this study is to describe the clinical and light microscopic findings in 4 patients with imipramine-induced hyperpigmentation and to better understand its origin. METHODS: All 4 patients underwent a skin biopsy for light microscopy. In 1 patient, a biopsy specimen was obtained for electron microscopy. Tissue from patient 1 was analyzed with a mass spectrophotometer, and energy-dispersive x-ray analysis was performed on tissue from patients 1 and 2. RESULTS: All 4 women had been taking imipramine for at least 2 years. Hyperpigmentation occurred in a photodistribution on the face, arms, and backs of the hands. Light microscopy in all cases demonstrated golden-brown granules in the superficial dermis, which were strongly positive for Fontana-Masson stain. Electron microscopy demonstrated areas of electron-dense inclusion bodies within macrophages, which were distinct from melanosomes. Mass spectrophotometric and energy-dispersive x-ray analysis of the electron-dense bodies showed the presence of sulfur atoms, and no peak corresponding to that expected for imipramine was found. A peak closely corresponding to phaeomelanin, a sulfur-containing compound, was found. CONCLUSION: Hyperpigmentation is a side effect of long-term imipramine use. It may result from the deposition of melanin in an unusual form. The melanin pigment is possibly complexed with a metabolite of imipramine, and does not represent the deposition of imipramine in its native form.
Aged↗
Cutaneous melanoma with myxoid features: twelve cases with differential diagnosis.
Substantial myxoid change can occur in malignant melanoma, but its importance in primary disease has not been systematically evaluated. This report describes the clinical, microscopic, histochemical, and immunohistochemical findings in 12 patients with primary cutaneous malignant melanoma with myxoid features. The tumors presented as solitary lesions situated on the limbs (six lesions), trunk (four lesions), and head and neck (two lesions). The patients included six women and six men, whose ages ranged from 26 to 95 years, with a mean of 63 years. Breslow thickness varied from 0.48 mm to more than 12 mm, with a mean of more than 3.2 mm. Clinical follow-up for an average of 22 months showed one local recurrence, but no evidence of metastases yet. In all cases, there was a combination of myxoid and nonmyxoid areas. A minimum of 15% myxoid cross-sectional area was required for inclusion in the study, and up to 80% was observed. The pale blue mucin identified on hematoxylin and eosin staining was sensitive to hyaluronidase and positive for alcian blue in the 10 cases stained. Immunohistochemical staining was positive for S-100 in all 9 cases stained, positive for HMB-45 in 9 (90%) of 10, and negative for cytokeratin in all 9 cases in which myxoid melanoma remained in the block after previous sections. The presence of myxoid stroma did not define a biologically significant subgroup of melanoma. Only in cases with extensive (>50%) myxoid stromal effacement of the melanoma was there a major diagnostic hurdle. The diagnosis of primary cutaneous melanoma with myxoid features was seldom as problematic as metastatic myxoid melanoma. Positive S-100 stains, negative cytokeratin immunohistochemical stains, and hyaluronidase-sensitive alcian blue staining assisted in the diagnosis of this entity.
Adult↗
Fetal DNA and cells in women with systemic sclerosis.
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Female↗
Kaposiform hemangioendothelioma. An aggressive, locally invasive vascular tumor that can mimic hemangioma of infancy.
BACKGROUND: Kaposiform hemangioendothelioma is a rare, aggressive vascular proliferation in children that is clinically and histologically distinct from hemangioma of infancy. It often manifests later than infantile hemangioma, and complication by Kasabach-Merritt syndrome is common. OBSERVATIONS: We examined 3 children with kaposiform hemangioendothelioma, all of whom were initially misdiagnosed as having infantile hemangioma. All 3 children developed Kasabach-Merritt syndrome, in association with a rapidly growing cutaneous vascular mass. Treatment with systemic corticosteroids, interferon alfa, vincristine, and radiation therapy appeared to halt progression of the disease. None had evidence of human herpesvirus 8 infection. CONCLUSIONS: Cutaneous kaposiform hemangioendothelioma may appear in early infancy but often appears months to years later. It is frequently complicated by Kasabach-Merritt syndrome, has no known association with Kaposi sarcoma related to human immunodeficiency virus infection, and demonstrates aggressive local behavior with invasion but not distant metastasis. Awareness of this entity is important to prevent a mistaken diagnosis of common hemangioma of infancy.
Child, Preschool↗
Mycosis fungoides with onset before 20 years of age.
BACKGROUND: Recent identification of mycosis fungoides (MF) in a man in whom the diagnosis was established at age 22 months prompted us to evaluate our experience with early onset MF. OBJECTIVE: Our purpose was to summarize the clinical characteristics and course of 24 patients in whom MF began by history before age 20 years and was confirmed by biopsy in 13 by that time. METHODS: A retrospective study was conducted. RESULTS: All 24 patients had patch/plaque disease and represented 4.3% of the 557 patients with cutaneous T-cell lymphoma seen by us since 1971. None progressed to a more advanced stage in up to 24 years (median, 12 years) after histologic diagnosis. Five patients (21%) presented with hypopigmentation. CONCLUSION: Early onset MF is not more aggressive than that appearing in adult life. MF should be considered in the differential diagnosis of chronic dermatoses in young persons, particularly in those presenting with hypopigmentation.
Adolescent↗
Melanoma and melanoma in situ: build a better diagnosis through architecture.
Conventional microscopy has remained the gold standard for melanoma diagnosis for several decades, and a diagnosis of melanoma is optimally based on a summation of microscopic features (criteria) that are evaluated as objectively as possible by an experienced histopathologist. Most pathologists and dermatopathologists assess multiple criteria before arriving at a diagnosis of melanoma, but the diagnosis remains somewhat subjective as different interpreters employ similar criteria but assemble them in very different ways. Due to the subjective aspects of the microscopic diagnosis of melanoma, considerable interobserver variability exists, even among expert diagnosticians. This article includes a brief analysis of the reproducibility of a diagnosis of melanoma with a comparison of architectural and cytological criteria. There is evidence to suggest that architectural attributes hold greater reproducibility over cytological features in the diagnosis of melanocytic neoplasms. If architectural criteria outperform cytological criteria in terms of reproducibility, then architectural features should probably be given preference over cytopathological aberrations in daily diagnosis. The author forwards four steps that can be used in the evaluation of any melanocytic neoplasm as well as an approach to melanoma diagnosis in which architectural features are emphasized.
Cell Division↗
Sweat gland carcinoma.
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Adenoma, Sweat Gland↗
Vascular adhesion molecules in oral lichen planus.
OBJECTIVE: Because recruitment and retention of lymphoid cells appear to be critical components of the pathogenesis of lichen planus, we have compared the expression and distribution of a panel of vascular adhesion molecules (ELAM-1, P-selectin, ICAM-1, VCAM-1, PECAM-1, CD34) and leukocyte adhesion molecule ligands (LFA-1, Mac-1, VLA4, L-selectin) in biopsies of this disease. STUDY-DESIGN: Frozen sections of 12 clinically and histologically confirmed cases of lichen planus and 9 normal control tissues were evaluated immunohistochemically with a standard 1-day avidin-biotin peroxidase technique. Staining intensity of vascular endothelium was evaluated semiquantitatively. Three microvascular zones or compartments were defined and evaluated separately. RESULTS: Generally, different staining patterns were observed in association with the various endothelium-associated adhesion molecules. In normal controls, PECAM was intensely expressed and VCAM-1 was weakly expressed. Intermediate staining was associated with ELAM-1, P-selectin, ICAM-1, and CD34. Staining within the three microvascular compartments frequently showed variations in intensity. In lichen planus, increased staining for ELAM-1, P-selectin, ICAM-1, and VCAM-1 was evident in one or more of the microvascular compartments. In the subepithelial vascular compartment where the infiltrate was the most dense, VCAM-1 appeared to show the greatest positive change. Almost all cells in the lichen planus infiltrates stained positive for ICAM-1, L-selectin, LFA-1, and VLA4, and large numbers of cells also exhibited VCAM-1, PECAM-1, and Mac-1 immunoreactivity. CONCLUSIONS: It appears that upregulation of ELAM-1, ICAM-1, and VCAM-1 (especially by endothelial cells in the subepithelial vascular plexus) could play a role in the pathogenesis of lichen planus. The expression of leukocyte receptors L-selectin, LFA-1, and VLA4 by most of the cells in the lichen planus infiltrate suggest that these molecules may be responsible for recruitment as well as retention in the active lichen planus lesion.
Adult↗
Eosinophilic and neutrophilic spongiosis: clues to the diagnosis of immunobullous diseases and other inflammatory disorders.
When eosinophils or neutrophils are found within the epidermis in concert with edema, the pattern is known as eosinophilic or neutrophilic spongiosis. Although eosinophilic spongiosis has been accepted as a clue to the diagnosis of blistering disorders for some time, the fact that either pattern can serve as a clue to the diagnosis of a variety of disorders, including immunobullous diseases, is less widely known. Herein, we review the types of inflammatory skin diseases, including spongiotic dermatitides, subepidermal vesicular dermatitides, intraepidermal vesicular dermatitides, and perivascular or diffuse dermatitides, that display intraepidermal eosinophils and neutrophils. We also review the known mechanisms that explain in part why intraepidermal granulocytes are commonly found in this diverse group of skin diseases.
Dermatitis↗
A call for logic in the classification of adnexal neoplasms.
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Histocytochemistry↗
Gottron's papules? Acanthosis nigricans.
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Acanthosis Nigricans↗
Eosinophilic folliculitis. The histologic spectrum.
We sought to define the light microscopic features of eosinophilic folliculitis as it occurs in human immunodeficiency virus (HIV)-infected individuals. The histologic findings of 52 biopsies from 50 patients were graded and compared with six biopsies of suppurative folliculitis from HIV-infected individuals. In all patients, clinical examination showed an eruption of pruritic follicular papules, and the folliculocentric nature of the disorder was confirmed histologically. Perifollicular infiltrates of lymphocytes and eosinophils were identified in all study biopsies, and there was also spongiosis of follicular epithelium. The inflammatory reaction was focused at the level of the follicular isthmus and the sebaceous duct. In all biopsies, lymphocytes and/or eosinophils were present within spongiotic follicular epithelium, but intrafollicular neutrophils were rare. Sebaceous glandular inflammation, eosinophilic pustule formation, and follicular rupture were present in less than half of the biopsies. Small numbers of microbes (bacteria, yeast, Demodex) were identified in 25% of the study biopsies in routine or special stains, but the organisms were away from areas of inflammation and were interpreted as nonpathogenic flora. The biopsies of suppurative folliculitis differed in that neutrophils and macrophages predominated in the infiltrate, microorganisms were readily identified in the inflammatory reaction, and the involved follicle was often ruptured. We believe that eosinophilic folliculitis is a unique HIV-associated dermatosis distinguishable from other folliculitides and papular dermatitides by clinical examination and light microscopy. We present our diagnostic approach.
Adult↗