Stem cells in the skin and their role in oncogenesis.

Stem cells generate great interest because they hold the promise for treatment of various incurable diseases. Several distinct stem cell populations have been identified in each organ, including the skin. As the skin is the largest organ in the body and is easily accessible, cutaneous stem cells have raised significant hopes for being a rich source of easily available multipotent stem cells. Genetic alterations and mutations in stem cells are being proposed as initiation step in multiple cancers. Small populations of oncogenic stem cells termed as cancer stem cells or tumour-initiating cells have been identified in multiple tumours, including squamous cell carcinomas, and melanomas that can sustain tumour growth, underlie its malignant behaviour and initiate distant metastases. These cells are controlled and regulated by the same pathways that are also responsible for maintenance and differentiation of normal stem cells. Developing a targeted therapy against the oncogenic stem cells and dysregulated members of the signalling pathways may be the key to understanding and treating skin cancers like melanomas, for which we still do not have an effective treatment.

CT features of plexiform neurofibroma of the submandibular gland.

Plexiform neurofibroma of the submandibular gland is an extremely rare tumor. We report the CT findings in a 6-year-old girl with type 1 neurofibromatosis who had a histopathologically proven submandibular gland plexiform neurofibroma. A "branching" hypodense mass was noted on the CT scan infiltrating the submandibular gland and the adjacent spaces of the neck. CT could be extremely valuable in suggesting the diagnosis.

Multiple basaloid follicular hamartomas associated with acrochordons, seborrhoeic keratoses and chondrosarcoma.

Basaloid follicular hamartoma is an uncommon neoplasm with distinctive histopathological findings. It presents as four distinctive clinical forms: a solitary papule, a localized plaque of alopecia, a localized linear and unilateral type, and generalized papules with associated alopecia and myasthenia gravis. Histologically, basaloid follicular hamartomas are characterized by thin branching strands and thick cords of basaloid or squamoid cells extending from a follicle into a loose, fibrillar, fibrocytic or mucinous connective tissue stroma. We report a case of long-standing, generalized basaloid follicular hamartomas associated with acrochordons, seborrhoeic keratoses, and a history of chondrosarcoma. In general, solitary tumours are sporadic; multiple tumours are inherited and frequently associated with a syndrome. Further surveillance is warranted to determine if the association of multiple basaloid follicular hamartomas and chondrosarcoma constitutes an inherited syndrome.

Plantar fibromatosis: use of magnetic resonance imaging in diagnosis.

For patients presenting with classic features of plantar fibromatosis, a presumptive diagnosis may be made on clinical grounds alone. In less clear cases, a biopsy may allow confirmation of the diagnosis; however, a biopsy exposes the patient to operative complications. Magnetic resonance imaging (MRI) offers a noninvasive method for confirmation of the clinical diagnosis that may obviate the need for a biopsy. We describe a case that demonstrates the potential of this technique.

Fluorescence of fungi in superficial and deep fungal infections.

BACKGROUND: Fluorescence of many fungi is noted when H&E stained sections are examined under a fluorescent microscope. In theory, this phenomenon could aid in the diagnosis of cutaneous and disseminated fungal infections without the delay associated with special stains. Seventy-six cases of superficial and deep fungal infections and 3 cases of protothecosis were studied to determine the clinical usefulness of this technique. RESULTS: In most cases, fluorescence was noted, but was not intense. Fluorescence of fungi did not correlate with the age of the specimen. In most cases, organisms in H&E stained sections were more easily identified with routine light microscopy than with fluorescent microscopy. CONCLUSION: This report suggests that in H&E stained skin specimens, fluorescent microscopy is of little benefit in the identification of fungal organisms.

Solitary nodule of the great toe.

We describe a 21-year-old woman with a subungual exostosis exhibiting both skin and nail findings. The patient presented with a firm, flesh-colored, nontender, subungual nodule in the distal nail bed of the great toe. Radiographic examination revealed focal calcification of the nodule, with direct communication to the underlying phalanx. Subungual exostosis should be considered in the differential diagnosis of any digital mass. Surgical excision, followed by curettage of the base, is the treatment of choice.

Dermatophytosis in the military.

Dr. Elston summarizes the US military experience with dermatophytosis in World War II and Vietnam and then brings us to the present and the current military situation with its increased role in humanitarian assistance.