My husband has a lump on the lobe in back of his ear. The lump has been there for about three years but has tripled in size in the last few months to about the size of a marble. He says that it is fine and nothing to worry about. I know that he should see a doctor. What is the best way to convince him of this fact?

S.W.

When in doubt, invoke the C-word (cancer). This may help motivate him a bit.

Whenever I am confronted with a mystery lump, I ask myself, "What tissues are present in this region?" This enables me to generate a list of possible diagnoses; this mental list, in turn, guides me in my suggestions regarding treatment.

Doctors call such a mental list a "differential diagnosis." The willingness to perform this mental exercise is what distinguishes a doctor from a hack. The hack says, "Let's see, the most common disorder that causes this symptom is disease X. I'll go ahead and treat for X, and if that doesn't work, then I'll think about it." (As opposed to a hack, a quack does not even bother to go through THIS much mental gymnastics.) A good doctor, on the other hand, will generate a differential diagnosis, take steps to eliminate ("rule out") the various nasty possibilities that are on the list, take other steps to confirm his or her suspicions, and THEN treat the problem.

Admittedly, there are several obvious diagnoses out there. Some folks walk into my office and I know (or think I know) what they have after a few minutes of conversation. Nevertheless, I still ask myself, "Is there anything else that this could be?"

Mystery lumps are NOT obvious, however. A good deal of caution must be exercised by the physician or surgeon who treats such lumps. Biopsy (removal of a small sample of the lesion for diagnostic purposes) is necessary, but in some cases a needle biopsy is best, while in other cases, incisional biopsy is best. (An incisional biopsy involves removal of a small chunk of the lesion.) In some cases, radiologic imaging (such as a CT or MRI scan) is necessary, in some cases not. Biopsy and imaging are often both necessary because the treatment of the tumor may be radically different depending on what type of tumor it is and how extensive it is.

So, what sort of tissues live in this area? In the area behind the ear, there is skin, fat, cartilage, bone, nerve, blood vessels and salivary-gland tissue (a portion of the parotid salivary gland extends behind the ear). Any of these tissues can give rise to a tumor, and these tumors can be benign or malignant. The main difference between the two: malignant tumors have the ability to spread to other parts of the body (metastasis), while benign tumors only cause problems locally. The ability to invade and destroy adjacent tissues is a hallmark of malignant tumors, but some malignant tumors do not do this, and some benign tumors can be very invasive.

Your husband's tumor (and it IS a tumor -- a tumor, after all, is just an abnormal growth of tissue) is most likely a skin or salivary gland tumor, but it could also have arisen from bone, fat, nerve and so forth. A good doctor would have a better idea of the probabilities after examining the tumor, but biopsy would still be essential. Cancer is definitely a possibility, and early diagnosis and treatment gives the patient the best chance for cure. If the logic of this escapes your husband, you may have to bribe, blackmail or bully him into a trip to the doctor.