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Biomedical subjects

L Requena

Publications and source records attributed to L Requena.

At least 73 records · Page 4Linked to original sources
PubMed1998

A new application of BCG antibody for rapid screening of various tissue microorganisms.

BACKGROUND: In routine dermatopathology there is growing demand for a simple, fast, cost-effective, and highly sensitive screening tool for the detection of microorganisms. OBJECTIVE: Our purpose was to determine whether immunostaining with polyclonal anti-Mycobacterium bovis (BCG), which is known for its interspecies cross-reactivity, is a suitable screening method for many common microorganisms in dermatopathologic specimens. METHODS: A total of 254 formalin-fixed, paraffin-embedded skin specimens of viral, protozoal, fungal, and bacterial infections were stained with appropriate histochemical stains and with anti-BCG. RESULTS: Anti-BCG labeled bacteria and fungi with high sensitivity and minimal background staining, but did not react with spirochetes, viruses, or protozoa (Leishmania). The quality and sensitivity of anti-BCG staining were superior to conventional histochemical stains. CONCLUSION: Because of its cross-reactivity with many bacteria and fungi as well as its high sensitivity and minimal background staining, the anti-BCG immunostain is a promising screening tool for the detection of the most common bacterial and fungal microorganisms in paraffin-embedded skin specimens.

Antibodies, Bacterial↗
PubMed1998

Cutaneous reactions at sites of herpes zoster scars: an expanded spectrum.

Several types of cutaneous lesions have previously been described at the sites of herpes zoster scars. We describe 16 patients with cutaneous lesions which had developed on herpes zoster scars. Biopsies were taken from these lesions, and a polymerase chain reaction assay was used to detect the viral genome in paraffin-embedded specimens. Histopathological findings enabled diagnosis of nonspecific granulomatous dermatitis in five patients, granulomatous vasculitis in two patients, lichen sclerosus in two patients, and pseudolymphoma, keloid, sarcoidal granuloma, granuloma annulare, granulomatous folliculitis, lichen planus and cutaneous Rosai-Dorfman disease, each in one patient. Varicella-zoster virus DNA was not identified in any of the patients. Granulomatous folliculitis, lichen sclerosus and cutaneous Rosai-Dorfman disease have not previously been described in herpes zoster scars, but they are three new cutaneous reaction patterns that may have developed within these scars. Our investigations indicate that the cutaneous reactions appearing in herpes zoster scars are not due to the persistence of varicella-zoster virus DNA within the lesions.

Adult↗
PubMed1998

Spinulosis of the face as a manifestation of demodicidosis.

We describe a 78-year-old woman with polycythaemia rubra vera who had multiple tiny follicular hyperkeratotic spicules on the cheeks. She was receiving treatment with oral hydroxyurea, but no topical agents had been applied to her face. Histopathological study demonstrated numerous Demodex folliculorum mites within dilated follicular infundibula, and we consider that the mites were playing a part in the aetiology of the skin lesions.

Aged↗
PubMed1998

Solitary plaque-like telangiectatic glomangioma.

We present a new clinicopathological variant of glomangioma. The lesion consisted of a painful solitary telangiectatic plaque on the right shoulder of a 33-year-old woman. It had been present for 3 years. Histopathology revealed ectatic vascular lumina within the dermis surrounded by glomus cells. Immunohistochemical and ultrastructural investigations confirmed the nature of the glomus cells. Acquired solitary plaque-like telangiectatic glomangioma is a new and distinctive variant of cutaneous glomus tumour.

Adult↗
PubMed1998

Lifelong severe verrucosis associated with human papillomavirus type 2: report of a case with a 38-year follow-up.

We describe a 67-year-old woman with disseminated warts which she had had for more than 38 years. The lesions consisted of common and plane warts, wart-like plaques and red-brownish macules similar to those in pityriasis versicolor. Furthermore, during follow-up, several solar keratoses, plaques of Bowen's disease and invasive squamous cell carcinomas were excised. The patient also had T-cell immunodeficiency of unknown aetiology. Histopathology demonstrated that all the warts showed the cytopathological features of common warts, but not those of the warts in epidermodysplasia verruciformis (EV). We investigated the presence of human papillomavirus (HPV) DNA in the warts by blot hybridization and molecular cloning and found that the lesions harboured HPV 2, but not EV-HPVs or other HPVs. In addition, the histopathological distribution of the viral DNA was confirmed in paraffin sections of warts from the patient at different ages by in situ hybridization. However, these investigations yielded negative results in specimens of Bowen's disease and invasive squamous cell carcinoma. These results demonstrated that the patient had been infected with HPV 2 from childhood, but the negative results for detection of DNA of HPV 2 in carcinomas from the patient do not support an oncogenic potential for HPV 2. In conclusion, HPV 2, an aetiological agent of common warts in the general population, may induce a lifelong severe verrucosis in some immunosuppressed patients.

Adult↗
PubMed1998

Cutaneous manifestations of infection by nontuberculous mycobacteria.

Cutaneous infections by nontuberculous mycobacteria (NTM) are not usual but their relative importance has changed during the last few years and still further changes are expected. This study comprised 13 patients from whom NTM were recovered from skin biopsy specimens, sinus exudates or cutaneous abscesses. All samples were processed according to standard methods, and the isolates were identified by biochemical testing. Skin biopsy specimens, when available, were processed for histopathological study. The clinical records of the patients were reviewed, and the relevant clinical, microbiological and epidemiological data collected. The clinical manifestations were noted to be relatively nonspecific and consisted of draining sinuses, abscesses, ulcers and nodules with multicentric or sporotrichoid patterns. Tissue culture isolated Mycobacterium fortuitum complex in nine patients, M. avium in three, and M. marinum in one. In the nine patients studied by histopathology, various patterns were observed. These included dermo-hypodermal abscesses, suppurative granulomas, tuberculoid granulomas and granulomas with a perifollicular distribution. Cutaneous lesions can thus be the first and the only sign of NTM disease, and culture still remains the definitive diagnostic procedure.

Adult↗
PubMed1998

Neoplasms with neural differentiation: a review. Part II: Malignant neoplasms.

Malignant peripheral nerve sheath tumors (MPNSTs) encompass a wide and unusual group of neoplasms with features of neural differentiation. They most commonly present as spindle cell neoplasms and it can be difficult to differentiate them from other spindle cell neoplasms such as leiomyosarcomas, fibrosarcomas and synovial sarcomas. Strict criteria need to be applied in order to make the diagnosis of MPNSTs. Helpful features include contiguity with a nerve or an association with von Recklinghausen disease. The use of immunohistochemical stains may also help to confirm the diagnosis. Markers such as S-100 protein, neurofilament, epithelial membrane antigen and Leu-7 (CD57) are frequently used to assess neural differentiation in these neoplasms. In addition to the spindle cell pattern, MPNSTs may also display an epithelioid pattern. Rarely, other elements may be seen including glands in the so-called glandular MPNST or muscle in triton tumors. In more unusual cases cartilage, adipose tissue and even bone are present. Also included in the group of MPNSTs are the peripheral neuroepithelial tumor, neurotropic or desmoplastic melanomas and malignant granular cell tumors. MPNSTs are highly aggressive tumors and should be treated accordingly.

Adult↗
PubMed1998

Mucinous metaplasia of apocrine duct.

Mucinous syringometaplasia is a rare condition characterized by the presence of mucinous cells lining eccrine ducts. Because most occurrences are on the palms and soles, the disorder is generally considered to be the result of chronic trauma or pressure. We describe an example of mucinous metaplasia involving an apocrine duct on the left arm of a 57-year-old woman. Histopathologic study demonstrated that in deeper areas of the invagination, the lining of the lumen consisted of columnar cells showing decapitation secretion and that the invagination was connected to a rudimentary hair follicle. These histopathologic features support the possibility that the involved duct was an apocrine one. We discuss the differential diagnosis with those cutaneous adnexal neoplasms in which the presence of mucinous cells has been described.

Adenoma, Sweat Gland↗
PubMed1998

Pigmented and nested sebomatricoma or seborrheic keratosis with sebaceous differentiation?

Recently, the term sebomatricoma has been proposed as the most appropriate denomination to avoid controversial and confusing terms and to encompass all benign neoplasms with sebaceous differentiation. We report on two specimens that may be interpreted as examples of two new histopathologic patterns in sebomatricoma, namely, pigmented and nested sebomatricoma, or as seborrheic keratosis with sebaceous differentiation. The first case consisted of a neoplasm composed of basaloid immature cells with features of sebaceous differentiation in the form of clusters of sebocytes and sebaceous ducts, in addition to the proliferation of dendritic melanocytes arranged as solitary units scattered through the neoplastic aggregations of immature germinative sebaceous cells. The second case, in addition to the proliferation of single dendritic melanocytes as the first case, showed well-defined nests of basaloid and heavily pigmented germinative sebaceous cells connected to the skin surface and numerous sebaceous ducts. In the first case, the pigmented nature of the lesion was the most striking histopathologic characteristic, whereas the nested pattern was remarkable in the second one. Immunohistochemical investigations demonstrated positivity of cytokeratin MNF116 in neoplastic aggregations of germinative sebaceous cells, whereas the clusters of mature sebocytes and sebaceous ducts expressed epithelial membrane antigen positivity. S-100 protein made evident the scattered dendritic melanocytes, but neoplastic cells resulted negative.

Basal Cell Carcinoma↗
PubMed1998

Tubular apocrine carcinoma arising in a nevus sebaceus of Jadassohn.

We present an example of tubular carcinoma that developed within a nevus sebaceus of Jadassohn on the scalp of a 53-year-old woman. The neoplasm showed features of sebaceous and apocrine differentiation. We review the literature about the malignant neoplasms arising in the nevus sebaceus of Jadassohn.

Adenocarcinoma↗
PubMed1998

Cutaneous pseudolymphoma in association with molluscum contagiosum.

Cutaneous pseudolymphomas have been defined as benign lymphocytic infiltrates of the skin that simulate cutaneous lymphoma clinically or histologically. The authors report on a 2-year-old boy with a lesion of molluscum contagiosum in which the inflammatory infiltrate that surrounded a cystlike structure containing molluscum bodies consisted of atypical hyperchromatic mononuclear cells with abundant mitotic figures, some of them atypical. Immunohistochemical investigation demonstrated that the infiltrate was predominantly composed of T lymphocytes. A previous report documented pseudoleukemia cutis associated with molluscum contagiosum, and this report expands the spectrum of histopathologic pseudomalignancies that may be seen in lesions of molluscum contagiosum.

Child, Preschool↗
PubMed1998

Histopathology of cutaneous reaction to granulocyte colony-stimulating factor: another pseudomalignancy.

Granulocyte colony-stimulating factor (G-CSF) is a hematopoietic growth factor (HGF) with many applications in cancer therapy. The most important applications are reduction in the incidence of febrile neutropenia, acceleration of neutrophil recovery after chemotherapy or bone marrow transplantation, and mobilization of progenitor cells. Many cutaneous adverse reactions associated with HGF have been reported in recent years, including injection site reactions, pyoderma gangrenosum, Sweet's syndrome, cutaneous leucocytoclastic vasculitis, and widespread folliculitis. The presence of large histiocytes on the dermis between collagen bundles has been proposed as a characteristic histopathologic finding in cutaneous eruptions secondary to granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor. We report on a patient with a high-risk ductal infiltrating carcinoma of the breast who received high-dose chemotherapy (HDC) with peripheral blood progenitor cell (PBPC) rescue. The patient received G-CSF after PBPC for a faster granulocyte recovery. She developed a cutaneous eruption located on back, buttocks, axillae, groin and sites where electrocardiography electrodes had been placed. From the histopathological point of view, the eruption was characterized by the presence of numerous large, atypical histiocytes in the dermis with several mitotic figures, mimicking involvement of the dermis by a malignant process.

Breast Neoplasms↗
PubMed1997

The histopathology of closed and open comedones of Favre-Racouchot disease.

OBJECTIVE: To determine the distinction between a comedo and an infundibular cyst of Favre-Racouchot disease. SETTING: A university hospital. PATIENTS: From the 8 patients included in the study, 19 cysts and comedones were evaluated. MAIN OUTCOME MEASURE: The distinguishing features between the cysts and comedones of Favre-Racouchot disease. RESULTS: All lesions were histologically indistinguishable from the primary comedones of acne vulgaris, except for the presence of a marked actinic elastosis in the surrounding dermis. The presence of a variable number of hair shafts and an abundant amount of bacteria, which was positive in the results of Gram staining and periodic acid-Schiff reaction and intermingled with sebum and eosinophilic laminated horny material within the dilated infundibulum, characterizes a comedo and differentiates it from an infundibular cyst. CONCLUSIONS: The cysts and comedones of Favre-Racouchot disease are closed and open comedones. They can be easily differentiated from an infundibular cyst by the histopathologic features rather than by the connection to the surface.

Aged↗
PubMed1997

Cutaneous vascular proliferation. Part II. Hyperplasias and benign neoplasms.

This second part of our review about vascular proliferations summarizes the clinicopathologic features of the cutaneous vascular hyperplasias and benign neoplasms. Hyperplasias comprise a heterogeneous group of vascular proliferations that eventually show a tendency to regression. Angiolymphoid hyperplasia with eosinophilia is included within the group of hyperplasias because of its historical denomination and its reactive nature, probably as a consequence of an arteriovenous shunt, although usually the lesions do not regress. Pyogenic granuloma, bacillary angiomatosis, intravascular papillary endothelial hyperplasia, and pseudo-Kaposi's sarcoma qualify as vascular hyperplasias because they regress when the stimulus that initiated them is removed. Benign neoplasms form a large group of hemangiomas with distinctive clinicopathologic characteristics, although some of them are of recent description and may produce diagnostic difficulties. We classified cutaneous benign vascular neoplasms according to their cell lineage of differentiation, for example, endothelial, glomus cell, and pericytic differentiation. Subsequent categories are established according to the size of the involved vessels (capillaries, venules and arterioles, or veins and arteries) or the nature of the proliferating vessels (blood or lymphatic vessels). Capillary and cavernous hemangiomas have been the terms classically used to name the most common variants of benign vascular neoplasms (i.e., infantile hemangiomas), but they are not the most appropriate denominations for these lesions. First, these names are not contrasting terms. Furthermore, most of the socalled "cavernous" hemangiomas are not hemangiomas (neoplasms) at all, but venous malformations. The most important conceptual issue is that, at any point in time, a particular hemangioma has its own histopathologic pattern throughout the depth of the lesion. For these reasons, we classified hemangiomas into superficial and deep categories. Some of the lesions reviewed have been recently described in the literature, and they may histopathologically mimic lesions of Kaposi's sarcoma; these include targetoid hemosiderotic hemangioma, microvenular hemangioma, tufted hemangioma, glomeruloid hemangioma, kaposiform hemangioendothelioma, spindle-cell hemangioendothelioma, and benign lymphangioendothelioma. In each of these lesions, we update and emphasize those clinical and histopathologic features that are helpful for differential diagnosis with lesions of authentic Kaposi's sarcoma in any of its three stages of development (patch, plaque, or nodule).

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1997

Cutaneous vascular anomalies. Part I. Hamartomas, malformations, and dilation of preexisting vessels.

Classification of cutaneous vascular anomalies is difficult because conceptual confusion persists between vascular neoplasms and malformations. However, hemangiomas of the infancy fulfill criteria both for hyperplasia and neoplasm because they result from proliferation of endothelial cells, but often undergo complete regression. Despite these pitfalls we have classified cutaneous vascular anomalies into the following categories: hamartomas, malformations, dilatations of preexisting vessels, hyperplasias, benign neoplasms, and malignant neoplasms. In this first part of our clinicopathologic review of vascular anomalies, hamartomas, malformations, and dilatation of preexisting vessels are covered. Hamartomas include several combined vascular and melanocytic proliferations grouped as phakomatosis pigmentovascularis and the so-called eccrine angiomatous hamartoma that consists of proliferations of both eccrine glands and blood vessels. Vascular malformations result from anomalies of embryologic development, and in some of them the abnormalities of the involved vessels are more functional than anatomic, as is the case of nevus anemicus. In contrast, other cutaneous vascular malformations show striking morphologic abnormalities of the vascular structures. These anatomic vascular malformations are subdivided into the following groups: capillary, venous, arterial, lymphatic, and combined anomalies. Spider angioma, capillary aneurysm-venous lake, and telangiectases are not vascular proliferations at all, but dilations of preexisting vessels. In our opinion, most of the lesions described with the generic term of "angiokeratoma" are not authentic vascular neoplasms, but hyperkeratotic malformations of capillaries and venules or acquired telangiectases of preexisting blood vessels of the papillary dermis. Therefore the first group of these "angiokeratomas" are included in the vascular malformations section, and the second group are covered in the section of dilation of preexisting vessels. Lymphangiectases are considered the lymphatic counterpart of angiokeratomas because they result from ectasia of preexisting lymphatic vessels of the papillary dermis.

Aneurysm↗
PubMed1997

Follicular mycosis fungoides: a clinicohistopathologic study.

BACKGROUND: Follicular mycosis fungoides (FMF) is a recently described variant of cutaneous T-cell lymphoma, histopathologically characterized by infiltrates of atypical CD4+ T lymphocytes around and within the epithelium of the hair follicles (folliculotropism). To date, only four cases of FMF have been reported. OBJECTIVE: Our goal was to identify cases of FMF and compare them with those previously reported. METHODS: The clinical and histopathologic features of three cases of FMF were analyzed. In addition, in one case immunohistochemical analysis in paraffin-embedded and frozen tissue as well as genotypic studies were performed. RESULTS: The three reported cases showed typical histologic findings of FMF, namely, perifollicular and intrafollicular infiltrates of atypical lymphocytes, in the absence of either epidermotropism or follicular mucinosis. Clinically, the lesions were similar to classic MF, but also contained follicular papules. Immunohistochemistry and gene rearrangement studies showed findings similar to classic MF. CONCLUSION: FMF is a rare variant of cutaneous T-cell lymphoma. Including our three cases, only seven patients have been reported. We hypothesize that the follicular epithelium in patients with FMF may express increased levels of skin-selective homing receptors and adhesion molecules. These may be involved in the induction of the folliculotropism of atypical lymphocytes.

Female↗