Diagnostic Histopathology最新文献

The number and range of tumour types that present in the sinonasal tract is staggering. The most recent WHO classification of head and neck tumours (5^th edition) attempts to simplify the issue by focusing on tumours that typically present in this anatomical site (with exclusion of lesions occuring elsewhere in the body). Even then, there are 24 discrete entities described; many of which have sub-variants and well documented histological pitfalls. In this mini-symposium we demonstrate 3 challenging cases from our routine practice that have required consideration of a broad range of entities in the differential diagnosis. The article is laid out in 3 sections covering undifferentiated malignancies, spindle cell lesions and tumours with divergent differentiation respectively. Sinonasal tumours may show considerable histological overlap between entities, and this is illustrated by the fact that many entities described in this article fall into more than one of the categories and some are even present in all three. In each section we recommend a methodical approach with careful consideration of the histological features in combination with appropriate ancillary studies in order to render as accurate a diagnosis as possible.

Fibro-osseous lesions of the jaws can be a challenging area of head and neck pathology due to significant overlap in histological appearance, requiring careful clinico-pathological correlation. In this review we aim to outline the fibro-osseous lesions which can present in the head and neck region, including; fibrous dysplasia, cemento-osseous dysplasia, juvenile trabecular ossifying fibroma, psammomatoid ossifying fibroma and cemento-ossifying fibroma. The clinical presentation, radiological appearance, histopathological features and differential diagnoses for each lesion will be discussed.

This review aims to update the readers on the expanding field of undifferentiated epithelial and neuroepithelial/neuroendocrine tumours of the sinonasal tract. Many of these tumours have similar cytomorphology and can be challenging when presented as a small biopsy. Judicious use of immunohistochemistry and next generation sequencing will determine the correct diagnosis and appropriate management.

Carvajal syndrome (MIM605676) is a cardiocutaneous disease with non-epidermolytic palmoplantar keratosis (PPK), hair anomalies (woolly hair or hypotrichosis) and dilated cardiomyopathy (DCM). Autosomal recessive inherited mutations in the desmoplakin (DSP) gene are causative for this disorder. Cardiac involvement may lead to heart failure and sudden cardiac death. Since this may require pacemaker and heart transplantation, early diagnosis and cardiologic screening is of great importance. We present a diagnostic case with typical but also hidden symptoms of Carvajal syndrome and its clinical follow up. A skin biopsy showed hyperkeratosis, acanthosis and “acantholysis of the desmosomal-type” as defined by hypereosinophilic epidermal keratinocytes, widening of the intercellular spaces and partial loss of the intercellular bridges in the suprabasal layers. Vesiculation, blistering, crusting and stronger inflammation were absent. We would like to point out the importance of a diagnostic skin biopsy and discuss the histologic differential diagnoses of acantholysis of the desmosomal-type.

Although rare, cancer of the vulva and penis have significant morbidity, mortality, and potentially psychologically distressing treatments. At both sites, squamous cell carcinoma (SCC) is the most common tumor type. Transitioning from classification systems reliant on histomorphology, two pathways of carcinogenesis are recognized in genital SCC based on human papillomavirus (HPV) infection status: HPV-associated and HPV-independent. Each pathway has unique etiology, pathology, molecular findings, and prognostic differences with clinically relevant outcomes. As more research comes to light, especially in vulvar pathology, a third potential pathway is emerging of HPV-independent, p53-wild type precursors and SCC. To familiarize pathologists with this group of diseases, we present an overview of HPV-associated and HPV-independent precursor lesions, as well as SCC, in both the vulva and penis.

The conjunctiva is a thin mucous membrane covering the anterior portion of the eye. Similar to the skin, the conjunctiva has normal resident melanocytes along the basal layer of the epithelium and these cells can give rise to melanocytic neoplasms of the conjunctiva. A variety of pigmented tumors can involve the conjunctiva, ranging from benign to malignant. Given the sensitive anatomic location and potential for some conjunctival melanocytic lesions to progress to melanoma, timely clinical recognition and correct histologic diagnosis of these tumors are essential in order to initiate the appropriate treatment and optimize outcomes. Clinicopathologic correlation is a vital step in this process. In this review article, the authors aim to provide an up-to-date concise, yet detailed, summary of the clinical, histopathologic, and molecular findings as well as a brief mention of management options for each type of conjunctival melanocytic lesion that may be encountered by pathologists and dermatopathologists.

Clear cell sarcoma of soft tissue is a rare aggressive soft tissue malignancy primarily affecting the extremities of young adults and is characterised by an EWSR1::ATF1 fusion gene. The tumour has a high rate of local recurrence and metastasis and as such often has a poor prognosis.

Histological assessment of a muscle biopsy is one of the most complex techniques which, currently in the UK, is only provided in very few specialist centres. This requires specialist laboratory skills in handling fresh tissue, freezing under optimal conditions, performing complex histochemical and immunohistochemistry staining on frozen tissue and specialist training for the histopathologists for interpretation and clinicopathological discussion. Access to electron microscopy and Genomic testing is also vital. This review will focus firstly on generic information on clinical indications, specimen handling, panel of histochemical and immunohistochemical stains and histological features of a normal paediatric muscle biopsy. The second section will focus on diagnostic features of a muscle biopsy specifically in the work-up of paediatric neuromuscular and metabolic conditions using case examples. The final section will focus on recent developments in genomic testing and the future prospects of muscle biopsy interpretation. Although complex, muscle biopsy interpretation is mentally stimulating and challenging, and it follows a schematic approach similar to medical liver or renal biopsies. In view of the complexity involved in procuring and handling the sample, muscle biopsy is usually not part of the early stages of work up. This makes it an extremely precious sample, but equally a rewarding exercise when histological interpretation provides the diagnosis and/or guides further genetic testing.

Basaloid neoplasms of the skin are often challenging not only to general pathologists but also dermatopathologists especially in the setting of partial sampling. While basal cell carcinomas make up most cutaneous neoplasms, there is a wide variety of both benign and malignant entities that have a basaloid morphology, which are particularly important to distinguish when present on skin in sensitive areas. Distinguishing between the malignant from the benign requires an understanding of the clinical presentation, histological correlation, emergence of new subclassification, as well as molecular discoveries. This chapter will examine the common cutaneous basaloid neoplasms encountered in routine practice and will highlight pitfalls to avoid misdiagnosis of rare but aggressive mimics.

The histopathological diagnosis of lichenoid dermatosis in the anogenital area is challenging. A wide range of conditions can display this pattern, often with overlapping features. Understanding clinicopathological characteristics, key histological clues and potential misleading appearances is crucial for an accurate diagnosis. Common entities like lichen planus or lichen sclerosus can vary in appearance depending on the specific variant or stage of evolution. Additionally, certain pathologies can closely mimic other conditions. For example, syphilis or paraneoplastic pemphigus may present changes identical to lichen planus, while "Mycoplasma pneumoniae-induced rash and mucositis" and paraneoplastic pemphigus can simulate erythema multiforme. Unusual patterns can also arise in cases of lichenoid contact dermatitis or condyloma lata in secondary syphilis. The presence of a plasma cell-rich lichenoid infiltrate serves as a clue for diagnosing plasma cell mucositis (Zoon) and syphilis. However, it is important to note that plasma cells may be outnumbered by lymphocytes in the former or completely absent in the latter. Therefore, in such cases, being aware of other subtle changes and recognizing the characteristics of the clinical presentation is crucial for arriving at the correct diagnosis. This review summarises practical information to empower the diagnostic precision of these challenging conditions.