Aggressive angiomyxoma is a rare mesenchymal tumor that most commonly arises in the vulvovaginal region, perineum, and pelvis of women. The term aggressive emphasizes the often infiltrative nature of the tumor and its frequent association with local recurrence. Patients often present with nonspecific symptoms which are frequently misdiagnosed with more common entities, such as a Bartholin cyst, lipoma, or hernia. Histologic examination reveals a hypocellular and highly vascular tumor with a myxoid stroma containing cytologically bland stellate or spindled cells. The tumor cells are characteristically positive for estrogen and progesterone receptors, suggesting a hormonal role in the development of the tumor. Chromosomal translocation of the 12q13-15 band involving the HMGA2 gene has been described. Surgical excision is the treatment of choice, although treatment with gonadotropin-releasing hormone agonists is an emerging therapy. Metastases are exceedingly rare, and overall, the prognosis is good.

As a supercooled melt at 150 °C, the chiral compound 1,1‘-binaphthyl racemizes rapidly. The melt solidifies as a conglomerate of crystals, each consisting exclusively of either R-(−)- or S-(+)-enantiomer. We find that crystallization performed with a 2.00 g sample with constant stirring produces a large enantiomeric excess (mean 77%) in almost every crystallization. The predominance of R-(−) or S-(+) was random. Unstirred 2.00 g samples of binaphthyl produce a much lower enantiomeric excess (mean 20%) with optical activity centered around zero similar to an earlier report. Thus, chiral symmetry breaking can be realized in crystallization from a melt by the mere act of stirring, as it can be in crystallization from a solution.

Squamous cell carcinomas of the head and neck (HNSCC) are a frequent diagnosis in anatomic pathology practice. Tobacco use and heavy alcohol consumption are known risk factors for HNSCC but in other cases human papillomavirus (HPV) is linked to carcinogenesis. HPV proteins E6 and E7 promote oncogenesis by blocking the action of p53 and pRB, respectively. An absence of p53 mutations in addition to expression of p16 are part of the distinct molecular profile identified in the subset of HNSCCs because of HPV. Various methods are available for HPV detection but polymerase chain reaction and in situ hybridization techniques are commonly used. Both methods are amenable for testing formalin-fixed paraffin-embedded tissue that is a sample type readily available to the pathologist. HPV is detectable in approximately a quarter of all HNSCCs, and is particularly prevalent in the oropharynx in which the positivity rates approach 40%. A vast majority of HPV-related HNSCCs are owing to HPV type 16 with types 18, 31, and 33 accounting for almost all of the remaining cases. HPV-related HNSCCs are associated with better prognosis for both recurrence and survival. This group of tumors has also been shown to respond well to radiation treatment. As the clinical relevance of HPV in HNSCCs continues to emerge, anatomic pathologists are likely to receive increasing requests for testing. Herein, the authors review the biological and clinical aspects of HPV-associated HNSCC and review techniques for HPV detection.

Chiral symmetry breaking in stirred crystallization of sodium chlorate ( NaClO3) occurs via the production of secondary crystals from a single "mother crystal." Martin, Tharrington, and Wu [Phys. Rev. Lett. 77, 2826 (1996)] investigated this phenomenon and concluded that it was mechanical crushing of a crystal by the stir bar, not convection, that produces secondary crystals from a single crystal. Here we report the generation of secondary crystals of sodium chlorate when a saturated solution of sodium chlorate is simply made to flow over a sodium bromate ( NaBrO3) crystal. This clearly shows that fluid flows alone can generate and disperse secondary nuclei.