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Genetics of thyroid lesions updated
S12
Pathology (2014), 46(S2)
PATHOLOGY 2014 ABSTRACT SUPPLEMENT
Dermatopathology: SY07-2
Dermatopathology: SY07-2
matrix lentigo, and an activation of the nail matrix melanocytes. Most importantly, longitudinal melanonychia may indicate an early stage of subungual melanoma. Subungual melanoma is a rare subtype of melanoma that usually originates and spreads from the nail matrix. Because of its poor prognosis and short matrix-to-bone distance, amputation has been traditionally performed. Recently, conservative surgery has been attempted for early subungual melanoma, but the evidence supporting this practice is sparse. As little is known about the progression pattern of subungual melanoma, further advances on the subject may provide better guidance on the optimal surgical approach. Histopathology slides, clinical records, and photographs of 23 cases of subungual melanoma were reviewed. For all cases, each area of the nail unit—proximal nail fold, nail matrix, nail bed, and/or hyponychium—in longitudinal sections was available for histological examination. Growth pattern, dermal invasion, and thickness were assessed in each area of the nail unit. There were five cases of melanoma in situ. Eighteen cases showed dermal invasion in at least one area of the nail unit. There were no cases showing dermal invasion in the nail matrix area only. In four cases, dermal invasion involved areas of the nail unit other than the nail matrix. In 14 cases, dermal invasion involved the nail matrix area as well as other areas of the nail unit. Except for one case, the nail matrix area showed thinner dermal invasion compared with dermal invasion in other areas of the nail unit. In conclusion, dermal invasion of subungual melanoma in the nail matrix area tends to occur later than other areas of the nail unit. Longitudinal incisional biopsy is necessary to accurately evaluate melanoma invasion. The findings of this study suggest that conservative surgical treatment for early subungual melanoma may be justified as the nail matrix area, an area of thin dermis and close proximity to the underlying bone, appears to be more resistant to invasion.
INFLAMMATORY AND NON-MELANOCYTIC TUMORAL PATHOLOGY OF THE NAIL
Endocrine Pathology: SC08-1
CAN YOU DIAGNOSE HAIR LOSS (NON-SCARRING ALOPECIA) Joyce S. S. Lee National Skin Centre, Singapore Alopecias are broadly divided into scarring and non-scarring forms. From a clinical perspective, follicular ostia are preserved in nonscarring alopecia, while histopathologically, there is preservation of follicular unit architecture, presence of intact sebaceous glands, and normal to near normal numbers of hair follicles. In chronic, longstanding non-scarring alopecias, follicular drop out may eventually ensue, resulting in absolute decrease in hair follicle numbers. Choice of biopsy site contributes significantly to accurate histopathological diagnosis. Areas of active hair loss are preferred. At the National Skin Centre, Singapore, it is routine practice to take two 4 mm punch biopsy specimens in suspected non-scarring alopecia; one specimen is sectioned vertically while the other is sectioned transversely. In non-scarring alopecias, transverse sections render very useful information. It allows for assessment of follicular unit integrity, hair counts, anagen:telogen and terminal:vellus hair ratios. It also allows for visualisation of all hair follicles within the biopsy specimen at a glance. In this talk, some common forms of non-scarring alopecias (e.g., androgenetic alopecia, alopecia areata, traction alopecia, trichotillomania, etc.) will be discussed, with emphasis on interpreting transverse sections.
Blanca Martin St Jonh’s Institute of Dermatology, UK The structure of the nail unit is complex and its knowledge is basic to achieve a correct diagnosis of nail biopsies. Inflammatory or infectious conditions that affect the nail can have a marked impact on a patient\’s quality of life. A wide-ranging variety of tumors can also develop in this region. In this lecture we will briefly review the anatomy and histology of the nail unit as well as the basic histopathologic findings in the most common inflammatory and infectious conditions affecting the nails. Furthermore, we will cover the most important non-melanocytic tumours that may arise in this area.
Dermatopathology: SY07-2 SUBUNGUAL MELANOCYTIC LESIONS Dong-Youn Lee Samsung Medical Center, Sungkyunkwan University, Seoul, Korea Subungual melanocytic lesions usually present with melanonychia. Melanonychia is defined as a brown or black pigmentation on a fingernail or toenail. Melanonychia, which is caused by melanin production in the nail matrix, appears as a longitudinal band. Longitudinal melanonychia is caused by nail matrix nevus, nail
GENETICS OF THYROID LESIONS UPDATED Alfred King-Yin Lam Griffith Health Institute, Griffith University and Gold Coast University Hospital, Gold Coast, Qld, Australia Advances in research into molecular biology of thyroid cancers have made exciting progress in the understanding of genetic pathways of the cancers. Despite the huge amount of genetic information of thyroid cancers, only a few genetic changes are of clinical value in the current settings. The best known genetic change is the roles of RET mutation in the diagnosis of the familial form of medullary thyroid carcinoma. The other important mutation of some clinical use is the detection of BRAF mutation in papillary thyroid carcinoma. BRAF mutation is associated with aggressive pathological parameters, radioiodine-refractory and increased cancer mortality. Other than these genetic changes in thyroid cancer, familial predisposition of non-medullary thyroid carcinoma is beginning to emerge. This includes a group that is syndromic which is characterized by predominance of non-thyroidal tumours such as familial adenomatous polyposis and PTEN hamartoma syndromes. The other group non-medullary thyroid carcinoma includes familial syndromes of thyroid cancers. Greater than 85% of these are papillary thyroid carcinoma. Overall, new genetic information continues to emerge in thyroid cancers and applications of the information would be expected in the diagnosis, prognosis and molecular target therapies.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
Pathology (2014), 46(S2)
PATHOLOGY 2014 ABSTRACT SUPPLEMENT
Dermatopathology: SY07-2
Dermatopathology: SY07-2
matrix lentigo, and an activation of the nail matrix melanocytes. Most importantly, longitudinal melanonychia may indicate an early stage of subungual melanoma. Subungual melanoma is a rare subtype of melanoma that usually originates and spreads from the nail matrix. Because of its poor prognosis and short matrix-to-bone distance, amputation has been traditionally performed. Recently, conservative surgery has been attempted for early subungual melanoma, but the evidence supporting this practice is sparse. As little is known about the progression pattern of subungual melanoma, further advances on the subject may provide better guidance on the optimal surgical approach. Histopathology slides, clinical records, and photographs of 23 cases of subungual melanoma were reviewed. For all cases, each area of the nail unit—proximal nail fold, nail matrix, nail bed, and/or hyponychium—in longitudinal sections was available for histological examination. Growth pattern, dermal invasion, and thickness were assessed in each area of the nail unit. There were five cases of melanoma in situ. Eighteen cases showed dermal invasion in at least one area of the nail unit. There were no cases showing dermal invasion in the nail matrix area only. In four cases, dermal invasion involved areas of the nail unit other than the nail matrix. In 14 cases, dermal invasion involved the nail matrix area as well as other areas of the nail unit. Except for one case, the nail matrix area showed thinner dermal invasion compared with dermal invasion in other areas of the nail unit. In conclusion, dermal invasion of subungual melanoma in the nail matrix area tends to occur later than other areas of the nail unit. Longitudinal incisional biopsy is necessary to accurately evaluate melanoma invasion. The findings of this study suggest that conservative surgical treatment for early subungual melanoma may be justified as the nail matrix area, an area of thin dermis and close proximity to the underlying bone, appears to be more resistant to invasion.
INFLAMMATORY AND NON-MELANOCYTIC TUMORAL PATHOLOGY OF THE NAIL
Endocrine Pathology: SC08-1
CAN YOU DIAGNOSE HAIR LOSS (NON-SCARRING ALOPECIA) Joyce S. S. Lee National Skin Centre, Singapore Alopecias are broadly divided into scarring and non-scarring forms. From a clinical perspective, follicular ostia are preserved in nonscarring alopecia, while histopathologically, there is preservation of follicular unit architecture, presence of intact sebaceous glands, and normal to near normal numbers of hair follicles. In chronic, longstanding non-scarring alopecias, follicular drop out may eventually ensue, resulting in absolute decrease in hair follicle numbers. Choice of biopsy site contributes significantly to accurate histopathological diagnosis. Areas of active hair loss are preferred. At the National Skin Centre, Singapore, it is routine practice to take two 4 mm punch biopsy specimens in suspected non-scarring alopecia; one specimen is sectioned vertically while the other is sectioned transversely. In non-scarring alopecias, transverse sections render very useful information. It allows for assessment of follicular unit integrity, hair counts, anagen:telogen and terminal:vellus hair ratios. It also allows for visualisation of all hair follicles within the biopsy specimen at a glance. In this talk, some common forms of non-scarring alopecias (e.g., androgenetic alopecia, alopecia areata, traction alopecia, trichotillomania, etc.) will be discussed, with emphasis on interpreting transverse sections.
Blanca Martin St Jonh’s Institute of Dermatology, UK The structure of the nail unit is complex and its knowledge is basic to achieve a correct diagnosis of nail biopsies. Inflammatory or infectious conditions that affect the nail can have a marked impact on a patient\’s quality of life. A wide-ranging variety of tumors can also develop in this region. In this lecture we will briefly review the anatomy and histology of the nail unit as well as the basic histopathologic findings in the most common inflammatory and infectious conditions affecting the nails. Furthermore, we will cover the most important non-melanocytic tumours that may arise in this area.
Dermatopathology: SY07-2 SUBUNGUAL MELANOCYTIC LESIONS Dong-Youn Lee Samsung Medical Center, Sungkyunkwan University, Seoul, Korea Subungual melanocytic lesions usually present with melanonychia. Melanonychia is defined as a brown or black pigmentation on a fingernail or toenail. Melanonychia, which is caused by melanin production in the nail matrix, appears as a longitudinal band. Longitudinal melanonychia is caused by nail matrix nevus, nail
GENETICS OF THYROID LESIONS UPDATED Alfred King-Yin Lam Griffith Health Institute, Griffith University and Gold Coast University Hospital, Gold Coast, Qld, Australia Advances in research into molecular biology of thyroid cancers have made exciting progress in the understanding of genetic pathways of the cancers. Despite the huge amount of genetic information of thyroid cancers, only a few genetic changes are of clinical value in the current settings. The best known genetic change is the roles of RET mutation in the diagnosis of the familial form of medullary thyroid carcinoma. The other important mutation of some clinical use is the detection of BRAF mutation in papillary thyroid carcinoma. BRAF mutation is associated with aggressive pathological parameters, radioiodine-refractory and increased cancer mortality. Other than these genetic changes in thyroid cancer, familial predisposition of non-medullary thyroid carcinoma is beginning to emerge. This includes a group that is syndromic which is characterized by predominance of non-thyroidal tumours such as familial adenomatous polyposis and PTEN hamartoma syndromes. The other group non-medullary thyroid carcinoma includes familial syndromes of thyroid cancers. Greater than 85% of these are papillary thyroid carcinoma. Overall, new genetic information continues to emerge in thyroid cancers and applications of the information would be expected in the diagnosis, prognosis and molecular target therapies.
Copyright © Royal College of pathologists of Australasia. Unauthorized reproduction of this article is prohibited.