Molecular Profiling of Syringocystadenocarcinoma Papilliferum Reveals RAS-Activating Mutations.

Context.—: Syringocystadenocarcinoma papilliferum (SCACP) is a rare adnexal carcinoma and the malignant counterpart of syringocystadenoma papilliferum (SCAP), which is commonly located on the head and neck and may arise in association with a nevus sebaceus. RAS mutations have been identified in both SCAP and nevus sebaceus.

Localised chronic fibrosing vasculitis versus erythema elevatum diutinum.

A woman in her 70s was referred for a painless plaque on the shin, present for 2 years and progressing in thickness. Examination revealed a large erythematous to violaceous indurated plaque with cobblestone appearance. Biopsy revealed an inflammatory infiltrate of neutrophils with scattered histiocytes, lymphocytes, eosinophils and plasma cells interspersed with areas of lamellar fibrosis and focal areas of vascular damage, suggestive of a localised chronic fibrosing vasculitis of the skin.

Cutaneous metastases of follicular thyroid carcinoma: a report of four cases and a review of the literature.

Cutaneous metastasis of follicular carcinoma of the thyroid is very rare, and when it occurs, can exhibit a variety of histologic appearances. The 4 cases presented here were identified from the surgical pathology files of the James Homer Wright Laboratories of Pathology at the Massachusetts General Hospital (MGH). The cases consisted of 4 patients, 3 men and 1 woman, aged 52 to 75 years, with cutaneous metastasis of follicular thyroid carcinoma.