Langerhans cell sarcoma with lineage infidelity/plasticity: a diagnostic challenge and insight into the pathobiology of the disease.

Langerhans cell sarcoma is a very rare and aggressive tumor of Langerhans cell lineage, for which aberrant expression of T-cell-related antigens has not yet been reported in a primary skin tumor. The authors describe the first known case of a primary cutaneous Langerhans cell sarcoma with lineage infidelity and use comparative genomic hybridization to investigate the genetic composition of the tumor and detect DNA copy number alterations throughout its entire genome. The case involves a 62-year-old woman who presented with an irregular nodule on the forehead surrounded by smaller lesions in its vicinity.

Rhabdomyosarcoma arising in a congenital melanocytic nevus.

A variety of malignancies have been reported to arise within congenital melanocytic nevi, most commonly malignant melanoma, but rarely rhabdomyosarcoma, liposarcoma, and malignant peripheral nerve sheath tumor as well. There have been only three documented cases of rhabdomyosarcoma arising within congenital melanocytic nevi: two embryonal rhabdomyosarcomas and one mixed liposarcoma and rhabdomyosarcoma. One of these cases was also associated with neurocutaneous melanosis.

Mullerianosis of inguinal lymph nodes: report of a case.

We report a case of florid mullerianosis involving inguinal lymph nodes, a simulator of metastatic adenocarcinoma. The patient was a 48-year-old woman with symptomatic leiomyomas and enlarged right inguinal lymph nodes. Microscopically two lymph nodes were partially or completely replaced by cystically dilated and small glands, many of which contained mucin.