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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
PubMed1990

Pigmented spindle cell naevus.

We report 22 cases of pigmented spindle cell naevus (PSCN). The usual appearance of these naevi is that of a heavily pigmented papule found mostly on the legs of young patients. Histologically, PSCN was characterized by symmetrical proliferation of spindle-shaped pigmented melanocytes grouped in large junctional nests. Pagetoid spread of single cells in the overlying epidermis was frequently found. In our opinion, PSCN is a distinctive benign acquired melanocytic naevus that in the past has been frequently misdiagnosed as atypical Spitz naevi or malignant melanoma.

Adolescent↗
PubMed1990

Sclerosing-sweat-duct (microcystic adnexal) carcinoma--a tumor from a single eccrine origin.

A patient with a sclerosing-sweat-duct carcinoma of the upper lip is reported. Histologically the tumour showed solid islands and strands of squamous cells and sparse small ductal structures, some of them containing central cores of dense eosinophilic keratin. All this was embedded in a sclerotic stroma. These features, in addition to positive immunoreactivity for carcinoembryonic antigen (CEA) in the lumina of small ducts, and the presence of S-100 protein-positive cells in some cords and ducts, are consistent with the notion that this tumour exhibits differentiation toward eccrine sweat structures.

Adenocarcinoma↗
PubMed1990

Papillary eccrine adenoma--a light-microscopic and immunohistochemical study.

We report a case of papillary eccrine adenoma. This benign cutaneous tumour had a diagnostic microscopic appearance that consisted of multiple dilated ducts lined by two or more layers of cells. The inner layer often formed intraluminal papillary projections of variable complexity. The lumina were filled by eosinophilic amorphous material. Immunoperoxidase studies showed carcino-embryonic antigen in the luminal border of the ducts, but S-100 protein was absent for tumoral ducts. We discuss the eccrine and apocrine differentiation of this neoplasm on the basis of the immunoperoxidase results. The differential diagnosis includes other cutaneous neoplasms with intraductal papillary proliferation.

Carcinoembryonic Antigen↗
PubMed1990

Spring eruption of the ears.

Spring eruption of the ears is a distinctive photo-dermatosis characterized by the onset of papules and vesicles on the light-exposed helix of the ears that usually develop in the early spring months and mainly affect juvenile males. Histologically the picture evolves according to evoluntionary stage of the lesions from a nodular dermal inflammatory infiltrate in papular lesions to subepidermal blisters in vesicles. The striking and isolated location on the ears and its onset as small outbreaks are clinical features resulting from unknown mechanisms.

Adult↗
PubMed1990

Aggressive keratoacanthoma of the eyelid: "malignant" keratoacanthoma or squamous cell carcinoma?

We report an aggressive keratoacanthoma of the upper eyelid that recurred at the site of a previously excised keratoacanthoma. The diagnosis was confirmed by biopsy. Because the surgery required would be extensive, medical therapy was tried first. The tumor was treated with intralesional injections of 5-fluorouracil and radiotherapy. Despite this therapy, the orbital computed tomogram showed tumor extension into the orbit, and an orbital exenteration was performed. Histopathology of the excised tumor was consistent with squamous cell carcinoma. We discuss the topic of malignant transformation of the keratoacanthoma.

Carcinoma, Squamous Cell↗
PubMed1990

Achromic verrucous large cell acanthoma.

Large cell acanthoma (LCA) is an epidermal neoplasm whose nature has been variously explained. Though frequently hyperpigmented, we describe for the first time an achromic case located on the dorsum of the right hand of a 83-year-old woman. This observation is largely inconsistent with one of the theories about the nature of this condition: that it is merely a solar lentigo with large nuclei of keratinocytes.

Aged↗
PubMed1990

Trichilemmal cyst under a compound melanocytic nevus.

Cystic dilatation of a hair follicle, folliculitis, abscess formation and epidermoid cysts are not infrequent findings in an intradermal melanocytic nevus. We herein report a trichilemmal cyst under a compound melanocytic nevus. To the best of our knowledge this association has not been previously reported.

Adult↗
PubMed1990

Angioleiomyoma within a histiocytoma.

We report an angioleiomyoma developed within a cellular histiocytoma on the calf of a 77-year-old man. The lesion consisted of a spherical nodule with two well-defined concentric areas. The outer circular area was a cellular histiocytoma and the inner central area consisted of an angioleiomyoma. Immunoperoxidase investigations for desmin demonstrated positivity in the angio-leiomyoma, whereas the histiocytoma remained negative. Serial sections of the lesion failed to demonstrate a connection between the angioleiomyoma and a normal vein which could have been trapped by the histiocytoma. The angioleiomyoma may have originated from a vessel in the histiocytoma.

Aged↗
PubMed1990

Trichoblastic fibroma.

We report a trichoblastic fibroma in the groin of a 60-year-old woman. This unusual tumor showed a predominance of epithelial component, with abundant basophilic, well-circumscribed, epithelial lobules and some keratinous cysts. Several areas suggested stromal induction of differentiation, and in the keratinous cysts there were indications of outer hair sheath differentiation. We review the clinical data from published cases of trichogenic hair germ tumors and discuss the differential diagnosis.

Epithelium↗
PubMed1990

Multinodular hemosiderotic dermatofibroma.

We describe a patient who developed a pigmented plaque on the anterior aspect of his right knee clinically mimicking angiokeratoma circumscriptum or malignant melanoma. Histopathological examination demonstrated a multinodular hemosiderotic dermatofibroma in which the cellular tumor islands were separated by areas of hyalinized collagen. Multinucleated giant tumor cells were found in the lumen of a medium-size vein underlying the tumor. The differential diagnosis of angiomatoid malignant fibrous histiocytoma, a tumor with clinical and morphologic similarities, is discussed.

Adult↗
PubMed1990

Periungual porocarcinoma.

We describe a patient who developed a porocarcinoma in the nail bed. His profession had exposed him to X-rays for many years, resulting in chronic radiodermatitis of several digits on both hands. He displayed an ulcer in the lateral nail fold of the right third digit which extended into the nail bed. The histology of the lesion was consistent with malignant eccrine poroma. Porocarcinoma has not been previously published in this location and this tumor must be considered in differential diagnosis of subungual malignant tumors.

Adenoma, Sweat Gland↗
PubMed1990

Trichogenic trichoblastoma. An unusual neoplasm of hair germ.

Tumors of hair germ are a very rare group of primary cutaneous neoplasms that have been divided into two groups: epithelial and mesenchymal. Epithelial neoplasms of hair germ are further subdivided into those that are purely epithelial (trichoblastomas) and into epithelial neoplasms with mesenchymal components that may cause inductive changes toward the earliest phase of hair follicle differentiation (trichoblastic fibroma) or a more advanced and complete hair follicle formation (trichogenic trichoblastoma). We herein report an ulcerated trichogenic trichoblastoma whose epithelial and mesenchymal components recapitulated the formation of numerous primitive dermal papillae of the hair bulb because there were numerous strands of small polygonal epithelial cells that delimited areas of a dense and abundantly cellular connective tissue in a hair papilla-like pattern.

Adult↗
PubMed1989

Verrucous trichoadenoma.

Two cases of verrucous trichoadenoma are reported. Clinically, both lesions were diagnosed as seborrheic keratoses, but histopathologically no areas of basaloid cell proliferation were seen in the numerous sections and there were many small, epidermoid cysts in the dermis which contained one or more vellous hairs. Some of these cysts expelled their horn material into the surface keratin layer in a "boiling pattern". We propose the term "verrucous trichoadenoma" for these tumors.

Aged↗
PubMed1989

Simultaneous occurrence of junctional nevus and seborrheic keratosis.

A 45-year-old man presented with a pigmented lesion on his face. A clinical diagnosis of melanocytic nevus was made and the lesion was excised. Histopathologic examination showed a reticular seborrheic keratosis associated with a junctional nevus. We discuss the relation of nevocellular nevi with epidermal and adnexal tumors.

Cheek↗
PubMed1989

Elastotic nodules of the ears.

A case of bilateral elastotic nodules of the ears is reported. This distinctive entity occurs on the ears in response to chronic actinic damage and is seen infrequently. Elastotic nodules of the ears may therefore be misdiagnosed clinically as basal cell carcinoma or some infiltrative process such as gout or amyloid. Although the lesions are usually found on the anthelix, they may also arise on the helix, and can then simulate chondrodermatitis nodularis helicis.

Diagnosis, Differential↗