Melanocytes of a melanocytic nevus in a lymph node from a patient with a primary cutaneous melanoma associated with a small congenital nevus

Aggregates of melanocytes within the parenchyma of a supraomohyoid lymph node were found in a lymph node dissection from a 52-year-old woman who had a primary cutaneous melanoma that had arisen in association with a small congenital nevus. The melanocytes in the lymph node were interpreted to be those of a benign melanocytic nevus, and not those of malignant melanoma, based on similarities in morphologic features and immunohistochemical staining between the melanocytes in the node and those in the cutaneous congenital nevus.     

Paraneoplastic pemphigus in a patient with a thymoma

A 76-year-old woman, with a history of thymoma, presented with a painful extensive stomatitis, painful paronychia, lichenoid papules on the hands and superficial erosions on the neck and the trunk. Histological examination showed lichenoid changes, acantholytic blister formation and apoptotic keratinocytes. Direct immunofluorescence was positive for IgG both in the epidermal intercellular spaces and along the basement membrane zone. Indirect immunofluorescence was similarly positive in a pemphigus vulgaris pattern. There was only a partial response to intravenous corticoids. These findings allowed the diagnosis of paraneoplastic pemphigus. The diagnostic characteristics, histopathology and the differential diagnosis of this disease are discussed.     

Histopatología de la uña

The structure of the nail unit is complex and many dermatologists and dermatopathologists have an incomplete understanding of it. Familiarity with the anatomy and histology of this unit, however, is a key factor in improving the diagnostic yield of nail biopsy. Inflammatory or infectious conditions that affect the nail can have a marked impact on a patient's quality of life. A wide-ranging variety of tumors can also develop in this region and they may be life-threatening or require surgery that will result in functional defects. The author reviews the anatomy and histology of the nail unit as well as the basic histopathologic findings in the most common conditions affecting the nails.     

When is a chrysanthemum dermatitis not a chrysanthemum dermatitis not a chrysanthemum dermatitis?

In order to provide a new reference point in the dermatological literature from which the naming of florists' chrysanthemums may be regularised and standardised, the case is presented for the use of the generic name Dendranthema together with a cultivar name in place of a specific epithet. A review of cultivar specificity in chrysanthemum dermatitis is also presented.