6-Methyl-ideneandrost-4-ene-3,17-dione.

In the title compound, C(20)H(26)O(2), which is the 6-methyl-ene derivative of androstenedione and a synthetic percursor of exemestane, the steroid A ring approximates to a sofa (or envelope) conformation, with the methyl-ene group adjacent to the link to the B ring lying out of the plane of the other atoms. The B and C rings have slightly flattened chair conformations and the D ring is an envelope, with the CH group forming the flap. In the crystal, mol-ecules are linked by two distinct C-H⋯O hydrogen bonds, involving acidic H atoms close to C=C and C=O double bonds.

5alpha-Androst-3-en-17-one oxime.

The title compound, C(19)H(29)NO, is a C17-oxime derivative of a potent aromatase inhibitor, which surprisingly has been found to have no inhibitory power. It crystallizes with two independent molecules in the asymmetric unit. C=N-O-H...N hydrogen bonds link pairs of molecules to form dimers almost parallel to the bc plane. Cohesion of the structure is also due to another three C-H...O hydrogen bonds directed along the a axis. This hydrogen-bonding scheme can be correlated to the almost complete loss of inhibitory power of the title compound.

Squamous cell carcinoma of the oral cavity: a clinicopathologic scoring system for evaluating risk of cervical lymph node metastasis.

A series of 126 cases of squamous cell carcinoma of the oral cavity with neck dissection was studied. Several clinicohistologic parameters and statistical correlation with lymph node metastasis were evaluated. Statistical association with metastasis was found in the following factors: microvascular invasion (P < 6 x 10(-7)), grade of differentiation (P < .0001), T category (P = .003), tumor thickness (P = .005), inflammatory infiltration (P = .011), tumoral interphase (P = .02), and perineural spread (P = .04). We designed a scoring system based on statistical results that eliminates the need for complex mathematical formulas. We tested this scoring system; cases with scores ranging form 7 to 12, 13 to 16, 17 to 20, and 21 to 30 points showed metastasis in 0%, 20%, 63.6%, and 86.3% of cases, respectively. The differences between these four groups in relation to rate of metastasis were very significant (P = 8 x 10(-9)). In conclusion, this scoring system is a reliable method of predicting risk of metastasis.