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Biomedical subjects

R Baran

Publications and source records attributed to R Baran.

At least 91 records · Page 5Linked to original sources
PubMed1996

Hutchinson's sign: a reappraisal.

Hutchinson's sign, periungual extension of brown-black pigmentation from longitudinal melanonychia onto the proximal and lateral nailfolds, is an important indicator of subungual melanoma. However, experience has demonstrated that Hutchinson's sign, although valuable, is not an infallible predictor of melanoma. Periungual pigmentation is present in a variety of benign disorders and, therefore, may lead to overdiagnosis of subungual melanoma. Periungual hyperpigmentation occurs in at least one nonmelanoma skin cancer, Bowen's disease of the nail unit. Hyperigmentation of the nail bed and matrix may reflect through the "transparent" nailfolds simulating Hutchinson's sign. "Pseudo-Hutchinson's sign" is a phrase coined to encompass these three simulants of Hutchinson's sign. Each represents a misleading clue to the diagnosis of subungual melanoma. Total reliance on the (apparent) presence or absence of periungual pigmentation may lead to overdiagnosis or underdiagnosis of subungual melanoma. All relevant clinical and historical information, including the presence or absence of periungual pigmentation, must be carefully evaluated in a patient suspected of having subungual melanoma. Ultimately, the diagnosis of subungual melanoma is made histologically.

Humans↗
PubMed1996

The lunula: a magnetic resonance imagining approach to the subnail matrix area.

High-resolution sagittal magnetic resonance images depict an oval area in the dermis beneath the nail matrix that gives a particular signal. This study defines the magnetic resonance imaging characteristics of this area and examines its correlation with the lunula. A high-resolution surface gradient coil specially designed for skin imagining was used on a 1.5 T magnetic resonance unit. The subnail matrix (SNM) areas of 12 subjects had a significantly longer T2 relaxation time and a higher enhancement ratio after injection of gadolinium than did the nail bed dermis. The length of the SNM area distal to the free edge of the proximal nail fold was highly correlated with the length of the lunula (R = 0.98) in 30 fingers and 10 toes. The total length of the SNM area was somewhat correlated with the nail thickness (R = 0.86) in 30 fingers. The histology and microvascularization of the subungual tissue in 21 fingers showed that this SNM area had specific features: The area was composed of loose connective tissue without bundles, and the reticular and subdermal vascular networks had large regular meshes in this oval area. The lunula is shown to be linked to a well-defined area in the underlying dermis with a specific histology and microvascularization.

Adult↗
PubMed1996

Intrathoracic tuberculous lymphadenopathy: clinical and bronchoscopic features in 17 adults without parenchymal lesions.

BACKGROUND: Whilst intrathoracic lymphadenitis is a characteristic sign of primary tuberculosis in children, its presence without parenchymal lesions in adults is unusual and makes the diagnosis using noninvasive techniques difficult. The diagnostic role of bronchoscopy in adults with intrathoracic tuberculous lymphadenitis is reported. METHODS: Seventeen patients with intrathoracic lymphadenopathy seen during 1993 who had all undergone bronchoscopy and had been found to have tuberculosis in the absence of any parenchymal lung lesions were evaluated retrospectively. RESULTS: Right paratracheal lymphadenopathy was observed on the plain chest radiograph in all the patients. Fifteen of the 17 patients had an endobronchial abnormality and samples taken at bronchoscopy gave a definitive diagnosis in nine (53%) of the 17. Four patients had ulcerating endobronchial granuloma and all had biopsy samples positive for tuberculosis. Transbronchial or transcarinal needle aspiration samples were diagnostic in five of 11 patients (45%) subjected to the procedure. Peripheral lymph node biopsy diagnosed tuberculosis in two cases and in the remaining six patients the diagnosis wa achieved by mediastinoscopy or thoracotomy. CONCLUSIONS: Bronchoscopy has an important role in the diagnosis of intrathoracic tuberculous lymphadenopathy in adults and should be considered before other invasive procedures.

Adolescent↗
PubMed1996

Psoriatic onycho-pachydermo-periostitis. A variant of psoriatic distal interphalangeal arthritis?

BACKGROUND: Joint and nail involvement in psoriasis is relatively common. In contrast, bony involvement of the terminal phalanx under a psoriatic nail is rare. We report on this psoriatic onycho-pachydermo-periostitis and suggest pathophysiologic mechanisms. OBSERVATIONS: Two new cases are reported and the data are compared with the data from eight similar cases reported in the literature. All subjects presented with similar changes--onychopathy, soft-tissue thickening, and radiologic features consisting of bone erosions and a periosteal reaction of the terminal phalanx. Of the 10 patients, two had no history of psoriasis before a diagnosis of psoriatic onycho-pachydermoperiostitis was made. The inflammation is likely transmitted from the psoriatic nail to the adjacent underlying bone by the same mechanism as in enthesopathies. CONCLUSION: Psoriatic onycho-pachydermo-periostitis should be recognized as a specific entity in the spectrum of psoriatic disease.

Adult↗
PubMed1996

[Fusarium onychomycosis].

INTRODUCTION: A 69-year-old man with an uneventful past history consulted for a proximal subungueal leukonychia and associated paronychia of the right greater toe. Macroscopic examination and culture lead to the diagnosis of Fusarium oxysporum. Local treatment with bifonazol and cyclopirox was effective. DISCUSSION: Fungal onychomycoses are uncommon and usually present as superficial leukonychia. The association of a proximal localization with paronychia would suggest possible Fusarium infection. Though no specific treatment protocol is well-established, this case emphasizes the importance of effective treatment since invasive fusariosis is described in immunosuppressed patients with ungueal localizations can be an important portal for infection.

Aged↗
PubMed1996

Significance and management of congenital malalignment of the big toenail.

Often misdiagnosed, congenital malalignment of the big toenail is not an uncommon condition. It consists of a lateral deviation of the long axis of nail growth relative to the distal phalanx. This would be of minor importance if it were not for local complications that may arise in infancy and adulthood. Some cases of this inherited dysplasia have demonstrated a tendency to spontaneous improvement. Therefore, photographic surveys should be made at regular intervals to monitor the need for possible surgery.

Bone Malalignment↗
PubMed1995

Localized multinucleate distal subungual keratosis.

Isolated distal subungual keratosis refers to a clinical monomorphic lesion involving one digit, but presenting different histological patterns. Among these, in four similar cases, we have observed the presence of multinucleate cells in localized distal subungual keratosis without an intervening granular layer, and without any clinical evidence of Darier's disease. To our knowledge, this constellation of anatomical and clinical features has not been reported previously.

Adult↗
PubMed1995

Transverse leukonychia of toenails due to repeated microtrauma.

Twelve women were seen with multiple transverse bands on the nail plates of the great toes. The bands were separated by normal nail, and had the same contour as the distal edge of the lunula. This disorder, which is usually bilateral, results from pressure on the free edge of the nail plate when it is not trimmed short.

Adult↗
PubMed1995

Nail changes in epidermolysis bullosa: clinical and pathogenetic considerations.

Nail changes in epidermolysis bullosa (EB) are common, but although they are highly suggestive of the disease, they are not pathognomonic. They are the result of abnormalities of the nail matrix and nail bed, associated with the pathogenetic alterations of the dermo-epidermal junction which occur in EB. In addition, secondary trauma in the areas of epidermal-dermal separation, and chronic inflammation of the nail matrix, are probable contributory factors, even in non-scarring forms of EB. Recent developments in the molecular and cell biology of the cutaneous basement membrane zone have greatly advanced our understanding of the pathomechanisms underlying different subtypes of EB. Defects in genes coding for the structural proteins of the basement membrane zone have been defined in some EB subtypes, and abnormal expression of structural proteins in others. The data accumulated from study of these genetic disorders will contribute to knowledge of the role of the dermo-epidermal junction in the normal physiology and differentiation of the nails, and be of value in discerning the aetiopathogenesis of acquired nail diseases.

Basement Membrane↗
PubMed1994

Longitudinal melanonychia caused by trichophyton rubrum. Histochemical and ultrastructural study of two cases.

Two patients had black pigmentation affecting a great toenail that clinically simulated longitudinal melanonychia; Trichophyton rubrum with a diffusible black pigment was consistently isolated from the nail lesions. Light microscopic examination of nail samples stained with hematoxylin-eosin-safranine showed hyphae containing a brown cytoplasmic pigment. The positive Masson-Fontana stain suggested that the pigment was related to melanin. Both histologic and ultrastructural studies demonstrated intracytoplasmic polymerization, a method of final enzymatic polymerization that is unusual for melanin-producing fungal strains.

Adult↗
PubMed1994

Invaginated fibrokeratoma with matrix differentiation: a new histological variant of acquired fibrokeratoma.

We report two cases of acquired fibrokeratoma which present new clinical and histological features specific to the nail apparatus. There are three histological characteristics. (i) A deep epithelial invagination which develops from the proximal nail fold and is orientated in the same direction as, but is more proximal than, the normal matrix. (ii) The postero-inferior aspect of the cul-de-sac produced by the invagination acts as an accessory matrix, giving rise to a pseudo-nail plate. The granular layer is reduced or absent. (iii) This accessory nail apparatus lies on a conical dermal tumour, sharply demarcated from the surrounding dermis, with a wide base narrowing towards the tip. The finger-shaped structure is reminiscent of Kint's type I acquired fibrokeratoma.

Female↗
PubMed1994

Clinical and histological patterns of dermatofibromas of the nail apparatus.

True fibromas develop as painless slow-growing nodular tumours. They may appear in any portion of the nail apparatus. The clinical features vary according to their anatomical site. In contrast, the histological features, consisting of a dermal hypocellular reticular nodule with ill-defined demarcation, were similar in all our patients, and factor XIIIa was negative.

Histiocytoma, Benign Fibrous↗