A systematic analysis of commonly used antibodies in cancer diagnostics.

AIMS: Immunohistochemistry plays a pivotal role in cancer differential diagnostics. To identify the primary tumour from a metastasis specimen remains a significant challenge, despite the availability of an increasing number of antibodies. The aim of the present study was to provide evidence-based data on the diagnostic power of antibodies used frequently for clinical differential diagnostics. METHODS AND RESULTS: A tissue microarray cohort comprising 940 tumour samples, of which 502 were metastatic lesions, representing tumours from 18 different organs and four non-localized cancer types, was analysed using immunohistochemistry with 27 well-established antibodies used in clinical differential diagnostics. Few antibodies, e.g. prostate-specific antigen and thyroglobulin, showed a cancer type-related sensitivity and specificity of more than 95%. A majority of the antibodies showed a low degree of sensitivity and specificity for defined cancer types. Combinations of antibodies provided limited added value for differential diagnostics of cancer types. CONCLUSIONS: The results from analysing 27 diagnostic antibodies on consecutive sections of 940 defined tumours provide a unique repository of data that can empower a more optimal use of clinical immunohistochemistry. Our results highlight the benefit of immunohistochemistry and the unmet need for novel markers to improve differential diagnostics of cancer.

Childhood actinic keratosis in an albino transforming into squamous cell carcinoma.

Actinic keratosis is a scaly, cutaneous lesion that is often seen in elderly patients. It is almost never seen in children and young adults. It develops on areas such as the face, ears and dorsa of the hands with chronic sun exposure. Actinic keratosis is a premalignant lesion, since histological changes in the epidermis may progress to squamous cell carcinoma if left untreated. There are roughly 70,000 people with albinism in India. These patients are prone to develop actinic keratosis which may undergo spontaneous remission or develop into invasive squamous cell carcinoma, basal cell carcinoma and malignant melanoma.We present an unusual case of a 35 year old albino who developed actinic keratosis at the age 15 years which progressed to squamous cell carcinoma.

Spectrum of non-infectious erythematous, papular and squamous lesions of the skin.

BACKGROUND: Dermatopathologists base their diagnostic approach on the tissue reaction pattern. This study mainly includes the interpretation of two major tissue reaction patterns, the psoriasiform and the lichenoid reactions, with clinicopathological correlation. AIMS: To analyze the spectrum of non-infectious erythematous papular and squamous lesions of the skin at our institute, study the age, sex and anatomic distribution pattern and classify the lesions into major categories; determine the incidence of each subcategory. STUDY PERIOD: two years; prospective, sample size: 161 cases, proforma filled. RESULTS: The lesions comprised 15.80% of the total load of surgical pathology and 30.99% of total number of skin biopsies. The highest percentage was in the 30-40 year age group (28.6%) with a male preponderance of 60.25%. The extremities were most frequently involved (67.79%). Lichenoid lesions were the commonest (46.57%) with lichen planus 26.7% and psoriasis vulgaris-19.88% being the most frequent. There were 5.6% seropositive cases. Correlation with the histopathological diagnosis was positive in 97.52% cases and negative in 2.48% cases. CONCLUSION: The contribution of histopathology to the final diagnosis was significant. It confirmed the diagnosis in 92.55% and gave the diagnosis in 4.97% cases.