Ayman Al Habeeb

Virtual microscopy using whole-slide imaging as an enabler for teledermatopathology: A paired consultant validation study.

Background: There is a need for telemedicine, particularly in countries with large geographical areas and widely scattered low-density communities as is the case of the Canadian system, particularly if equality of care is to be achieved or the difference gap is to be narrowed between urban centers and more peripheral communities. Aims: 1. To validate teledermatopathology as a diagnostic tool in under-serviced areas; 2. To test its utilization in inflammatory and melanocytic lesions; 3. To compare the impact of 20× (0.5 μm/pixel) and 40× (0.25 μm/pixel) scans on the diagnostic accuracy. Materials and Methods: A total of 103 dermatopathology cases divided into three arms were evaluated by two pathologists and results compared. The first arm consisted of 79 consecutive routine cases (n=79). The second arm consisted of 12 inflammatory skin biopsies (n=12) and the third arm consisted of 12 melanocytic lesions (n=12). Diagnosis concordance was used to evaluate the first arm. Whereas concordance of preset objective findings were used to evaluate the second and third arms. Results: The diagnostic concordance rate for the first arm was 96%. The concordance rates of the objective findings for the second and third arms were 100%. The image quality was deemed superior to light microscopy for 40× scans. Conclusion: The current scanners produce high-resolution images that are adequate for evaluation of a variety of cases of different complexities.

Significant overexpression of the Merkel cell polyomavirus (MCPyV) large T antigen in Merkel cell carcinoma.

The purpose of this study was to determine the expression pattern of the Merkel cell polyomavirus (MCPyV) large T‐protein antigen in patients with Merkel cell carcinoma.

Sebaceous gland carcinoma of the head and neck: The Princess Margaret Hospital experience

The purpose of this study was to identify prognostic factors predicting outcomes in sebaceous gland carcinomas.

Identification of novel target proteins in sebaceous gland carcinoma

The aim of this study was to identify new target proteins in sebaceous gland carcinoma.

Non-melanocytic mimics of melanoma, part II: intradermal mimics

Intradermal melanoma diagnosis poses a great deal of confusion on many occasions since it can mimic almost any tumour within the dermis. In part I, the different features of intraepidermal mimics were discussed. In this part, there is discussion of the clinical, cytomorphological and immunohistochemical features of intradermal mimics of melanoma and how to distinguish these conditions from melanoma. There is also a description of the ultrastructural features of some of these conditions that may help to distinguish melanoma from its mimics. It is hoped that this approach, together with part I of the non-melanocytic mimics of melanoma, will aid in better overall understanding of melanoma and its mimics.

Neuroendocrine carcinoma of the skin--an updated review.

Primary neuroendocrine carcinoma of the skin, or Merkel Cell carcinoma (MCC), is a rare but aggressive tumor. Many recent advances on the morphology, immunophenotype, and pathogenesis have come to light in recent years. This review highlights the clinical features, varying histologies, histogenesis, advances in molecular pathology, prognosis, and current management of MCC. It also aims to aid in the differential diagnosis, with an emphasis on neuroendocrine tumors, and approach to the diagnosis of MCC with the use of immunohistochemistry and molecular studies.

Cutaneous solitary neural hamartoma: report of an unusual case.

Cutaneous hamartomas are tumor-like proliferations of tissue indigenous to the organ but arranged abnormally. There are examples in the literature of cutaneous hamartomas composed of a variety of different components. To our knowledge, there is no previous report of such cutaneous solitary neural hamartoma. Our case occurred in a 51-year-old man with pain and paresthesia in the right shoulder associated with a nodule that was surgically removed. There was no history of trauma, other skin nodules, neurofibromatosis, or tuberous sclerosis. Histologically, there was an unencapsulated nodule, composed of mature nerve bundles noted abnormally high within the papillary dermis, extending to the reticular dermis with periadnexal distribution. Immunohistochemically, the nerve bundles were positive for S-100, including the smaller nerve twigs, and the perineurium was highlighted by epithelial membrane antigen, reminiscent of normal peripheral nerves. Although, neural components including mature nerve bundles have been described in various cutaneous hamartomas, this represents a peculiar case of a cutaneous mature peripheral nerve hamartoma. Whether this is related to other entities of cutaneous hamartomas (ie, neurofollicular hamartoma, folliculosebaceous cystic hamartoma) is not yet apparent, although it is probably a unique entity.

Microangiopathic hemolytic anemia and leukoerythroblastic blood film heralding bone marrow metastatic gastroesophageal adenocarcinoma.

Despite modern technological advancements in laboratory hematology, the blood film remains an important diagnostic aid. Herein, we report the case of a patient with a history of gastric cancer, who presented seven years following apparently successful surgery and adjuvant chemo-radio-therapy, with blood film findings of microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and leukoerythroblastosis (LEB). Although mimicking features of thrombotic thrombocytopenic purpura (TTP), subsequent bone marrow examination instead revealed an association with occult recurrence of necrotic, metastatic gastric adenocarcinoma. This case report and literature review highlight these rare, but important, hematological manifestations of gastric cancer, and the importance of astute laboratory and bone marrow investigations in preventing delays in appropriate treatment of the underlying malignancy.

Spindle cell melanocytic lesions: part II—an approach to intradermal proliferations and horizontally oriented lesions

Melanocytic lesions show great morphological diversity in their architecture and the cytomorphological appearance of their composite cells. Whereas functional melanocytes show a dendritic cytomorphology and territorial isolation, lesional nevomelanocytes and melanoma cells typically show epithelioid, spindled or mixed cytomorphologies, and a range of architectural arrangements. Spindling is common to melanocytic lesions, and may either be a characteristic feature or a divergent appearance. The presence of spindle cells may mask the melanocytic nature of a lesion, and is often disconcerting, either due to its infrequent appearance in a particular lesion or its interpretation as a dedifferentiated phenotype. Spindle cell melanocytic lesions follow the full spectrum of potential biological outcomes, and difficulty may be experienced judging the nature of a lesion due to a lack of consistently reliable features to predict biological behaviour. Over time, recognition of numerous histomorphological features that may portend a more aggressive lesion have been identified; however, the translation of these features into a diagnostic entity requires a gestalt approach. Although most spindle cell melanocytic lesions may reliably be resolved through this standard approach, problem areas do exist for the surgical pathologist or dermatopathologist. With this review (part II of II), we complete our discussion of spindle cell melanocytic lesions, in order to: (1) model a systematic approach to such lesions; and (2) provide familiarity with those melanocytic lesions which either typically or occasionally display a spindled cytomorphology.

Spindle cell melanocytic lesions--part I: an approach to compound naevoidal pattern lesions with spindle cell morphology and Spitzoid pattern lesions.

Melanocytic lesions show great morphological diversity in their architecture and the cytomorphological appearance of their composite cells. Whereas functional melanocytes reveal a dendritic cytomorphology and territorial isolation, lesional naevomelanocytes and melanoma cells typically show epithelioid, spindled or mixed cytomorphologies and a range of architectural arrangements. Spindling is common to melanocytic lesions, and may be either a characteristic feature or a divergent appearance. The presence of spindle cells may mask the melanocytic nature of a lesion, and is often disconcerting, either because of its infrequent appearance in a particular lesion or its interpretation as a dedifferentiated phenotype. Spindle cell melanocytic lesions follow the full spectrum of potential biological outcomes, and difficulty may be experienced judging the nature of a lesion because of a lack of consistently reliable features to predict biological behaviour. Over time, recognition of numerous histomorphological features that may portend a more aggressive lesion have been identified. However, the translation of these features into a diagnostic entity requires a gestalt approach. Although most spindle cell melanocytic lesions can reliably be resolved with this standard approach, problem areas do exist and cause no end of grief to the surgical pathologist or dermatopathologist. In this review, the authors present their algorithmic approach to spindle cell melanocytic lesions and discuss each entity in turn, in order to (1) model a systematic approach to such lesions, and (2) provide familiarity with those melanocytic lesions that either typically or occasionally display a spindled cytomorphology.