Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Nevus?

…of the examples cited, nevus pertains to a birthmark, i.e., a hamartoma. The word nevus in dermatology, however, is not used simply as a synonym for birthmark. It also is applied to a particular acquired proliferation of melanocytes known as a melano…

Differential Diagnosis in Dermatopathology

Discussions

…of the skin and the commonest neoplasm to develop within the hamartoma named badly nevus sebaceus (it is a hamartoma with abnormalities of many elements of the skin, not simply ones sebaceous). In actuality, squamous-cell carcinoma is a thousand tim…

Differential Diagnosis in Dermatopathology

Discussions

…tly to pose a dilemma diagnostic, even though the former is a hamartoma and the latter an adenocarcinoma. Both may have several findings histopathologic in common: presence of infundibular cyst-like structures scant stroma, epithelial components conn…

Differential Diagnosis in Dermatopathology

Sebaceous hyperplasia vs. Nevus sebaceus of Jadassohn

A malignant neoplasm of melanocytes that, in the skin, begins as a macule and may become a patch or a papule. A flat lesion of melanoma tends to be asymmetrical, poorly circumscribed with a scalloped, jagged, or notched border, and variegate, mostly…

Differential Diagnosis in Dermatopathology

Trichoadenoma vs. Microcystic adnexal carcinoma

A malignant neoplasm of melanocytes that, in the skin, begins as a macule and may become a patch or a papule. A flat lesion of melanoma tends to be asymmetrical, poorly circumscribed with a scalloped, jagged, or notched border, and variegate, mostly…

Differential Diagnosis in Dermatopathology

Discussions

…s the name denotes, is a hyperplasia, whereas the latter is a hamartoma that involves not only sebaceous units, but other adnexal epithelial structures, the epidermis, the dermis, and the subcutaneous fat. The lesion tends to be alopecia. Lesions ste…

Differential Diagnosis in Dermatopathology

Trichoblastoma, small nodular type vs. Trichoblastoma, large nodular type

A malignant neoplasm of melanocytes that, in the skin, begins as a macule and may become a patch or a papule. A flat lesion of melanoma tends to be asymmetrical, poorly circumscribed with a scalloped, jagged, or notched border, and variegate, mostly…

Histologic Diagnosis of Inflammatory Skin Diseases

Definition of Inflammation in Historical Perspective

…stations of disease, the others being neoplasia, hyperplasia, hamartoma, malformation, degeneration, and cyst. With regard to the skin, Ferdinand Hebra, in the third volume of Virchow’s Handbook of Special Pathology and Therapy published in 186…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Blaschkitis?

…wn inflammatory dermatitis in the lines of Blaschko nor to an hamartoma nor to an X-linked disease. Cutaneous antigenic mosaicism, the expression of which might be induced by a viral infection, could trigger this localized inflammatory T-cell respons…