Three different clinical faces of the same histopathological entity: hair follicle nevus, trichofolliculoma and accessory tragus.

BACKGROUND: Hair follicle nevus is a rare, congenital hamartoma with follicular differentiation characterized histologically by numerous, tiny, mature hair follicles. Trichofolliculoma, the histopathological features of which are quite similar to those of hair follicle nevus, is also a hamartoma that differs from hair follicle. Accessory tragus is a relatively common, benign congenital abnormality of the external ear with an incidence rate of 1 to 10 per 1,000 live births. OBJECTIVE: This study seeks to assess the discriminatory value of currently available, histological criteria in the differential diagnosis of hair follicle nevus, accessory tragi and trichofolliculoma. METHODS: Twenty-one patients comprising 9 cases of hair follicle nevus, 8 accessory tragi patients and 4 trichofolliculoma cases, were recruited to perform the study. RESULTS: There were 10 males and 11 females in the study group. No significant difference was observed between the three study groups in terms of age, gender or histopathological parameters such as density of hair follicles, subcutaneous fat score and presence of connective tissue framework. Cartilaginous component was seen in 8 cases that were diagnosed as accessory tragi, while central cyst and radiating hair follicles were seen in 4 cases which were diagnosed as trichofolliculoma. CONCLUSION: The results of our study showed that diagnostic discrimination of these diseases could be made only with the clinicopathologic correlation because of their clinical and histopathological similarities.

Three different clinical faces of the same histopathological entity: hair follicle nevus, trichofolliculoma and accessory tragus

AbstractBACKGROUND:Hair follicle nevus is a rare, congenital hamartoma with follicular differentiation characterized histologically by numerous, tiny, mature hair follicles. Trichofolliculoma, the histopathological features of which are quite similar to those of hair follicle nevus, is also a hamartoma that differs from hair follicle. Accessory tragus is a relatively common, benign congenital abnormality of the external ear with an incidence rate of 1 to 10 per 1,000 live births.OBJECTIVE:This study seeks to assess the discriminatory value of currently available, histological criteria in the differential diagnosis of hair follicle nevus, accessory tragi and trichofolliculoma.METHODS:Twenty-one patients comprising 9 cases of hair follicle nevus, 8 accessory tragi patients and 4 trichofolliculoma cases, were recruited to perform the study.RESULTS:There were 10 males and 11 females in the study group. No significant difference was observed between the three study groups in terms of age, gender or histopathological parameters such as density of hair follicles, subcutaneous fat score and presence of connective tissue framework. Cartilaginous component was seen in 8 cases that were diagnosed as accessory tragi, while central cyst and radiating hair follicles were seen in 4 cases which were diagnosed as trichofolliculoma.CONCLUSION:The results of our study showed that diagnostic discrimination of these diseases could be made only with the clinicopathologic correlation because of their clinical and histopathological similarities.

Monitoring wound healing of elastic cartilage using multiphoton microscopy.

OBJECTIVE: To demonstrate the ability of multiphoton microscopy (MPM) for monitoring wound healing of elastic cartilage. METHOD: In a rabbit ear model, four cartilage specimen groups at 1-day, 1-, 4-, 20-week healing time points as well as a normal elastic cartilage were examined with MPM without using labeling agents. MPM images at wound margins were obtained from specimens at different healing stages, compared with the Hematoxylin and Eosin (H&E) stained images. Image analysis was performed to characterize the collagen morphology for quantifying the wound healing progression of elastic cartilage. RESULTS: MPM provided high-resolution images of elastic cartilage at varying depths. Comparisons of the images of specimens at different healing stages show obvious cell growth and matrix deposition. The results are consistent with the histological results. Moreover, quantitative analysis results show significant alteration in the collagen cavity size or collagen orientation index during wound healing of elastic cartilage, indicating the possibility to act as indicators for monitoring wound healing. CONCLUSION: Our results suggested that MPM has the ability to monitor the wound healing progression of elastic cartilage, based on the visualization of cell growth and proliferation and quantitative characterization of collagen morphology during wound healing.

Human elastic cartilage engineering from cartilage progenitor cells using rotating wall vessel bioreactor.

Transplantation of bioengineered elastic cartilage is considered to be a promising approach for patients with craniofacial defects. We have previously shown that human ear perichondrium harbors a population of cartilage progenitor cells (CPCs). The aim of this study was to examine the use of a rotating wall vessel (RWV) bioreactor for CPCs to engineer 3-D elastic cartilage in vitro. Human CPCs isolated from ear perichondrium were expanded and differentiated into chondrocytes under 2-D culture conditions. Fully differentiated CPCs were seeded into recently developed pC-HAp/ChS (porous material consisted of collagen, hydroxyapatite, and chondroitinsulfate) scaffolds and 3-D cultivated utilizing a RWV bioreactor. 3-D engineered constructs appeared shiny with a yellowish, cartilage-like morphology. The shape of the molded scaffold was maintained after RWV cultivation. Hematoxylin and eosin staining showed engraftment of CPCs inside pC-HAp/ChS. Alcian blue and Elastica Van Gieson staining showed of proteoglycan and elastic fibers, which are unique extracellular matrices of elastic cartilage. Thus, human CPCs formed elastic cartilage-like tissue after 3-D cultivation in a RWV bioreactor. These techniques may assist future efforts to reconstruct complicate structures composed of elastic cartilage in vitro.