[Tissue arrays: Two simple and economical methods for manual construction.].

Objectives: Tissue array (TA) technologyis widely used as a method for the in situ investigation oftissue markers in cancer studies. A limitation of this techniqueis the high price of tissue arrayers. We describetwo easy and non-expensive manual methods, that haveproduced small and medium format arrays.

Nephrogenic adenoma: an immunohistochemical analysis using biotin-free methods.

Nephrogenic adenoma (NA) has been considered as a metaplastic process of the urothelium. It has been suggested that this lesion is of renal tubular cell origin or differentiation. Immunohistochemical studies of NA emphasize its staining with α-methylacyl-coenzyme A racemase (AMACR), and prostatic adenocarcinoma may be a possible differential diagnosis.

[Squamous cell carcinoma arising on an epidermal inclusion cyst: a case presentation and review of the literature].

Epidermal inclusion cysts are very common lesions that very rarely undergo malignant transformation-in the English-language literature we have only found 18 adequately documented cases. We present the case of a man with a 2-month history of a retroauricular skin lesion in which histological study revealed squamous cell carcinoma arising on an epidermal inclusion cyst. Cysts that grow rapidly, reach a large size, ulcerate, develop a fistula, or that do not respond to medical treatment, and those that recur should be excised completely and histological study performed of the whole lesion.

[Juvenile xanthogranuloma of the penis].

We report a case of juvenile xanthogranuloma of the penis in a 30 year old patient with clinical suspicion of epidermoid cyst. Histology and ethiopathogenesis are reviewed, with special emphasis on the differential diagnosis with other similar lesions with worst prognosis.