Q. I had a growth under the skin on the back of my neck. The surgeon who removed it called it a lipoma and said it was a fat tumor. I'd like to know a little more about this condition, whether it will recur and whether it is serious.

A. Lipomas are benign tumors of fat that can develop almost anywhere in the body. Most often they occur just under the skin on the back of the neck or on the back or the forearms. You may have just a single lipoma or several.

Lipomas feel like rubbery knots and usually cause concern because many people who first notice them worry that they may be a cancer. They generally cause no problems, other than a cosmetic one.

Occasionally they can grow in internal organs, such as the intestines, heart, brain or spinal cord and cause more troublesome problems. However, even in these locations, often no treatment is necessary.

If a lipoma is unsightly or causing symptoms, you can have surgery to cut it out, or liposuction, in which the fatty tumor is suctioned out through a small incision. Once removed, it usually doesn't recur.

Q. As a former resident of Brazil, I'm a big fruit eater and have always loved the mango, a fruit that unfortunately gives me an allergic reaction. I try not to eat more than half at a time, but even this quantity causes me to get little blisters on my lips. If I eat more than that, my face will swell and itch. Is this an unusual allergy of mine, or is there something in the mango causing this reaction?

A. It's not what's in the mango that's giving you trouble, it's what's on it.

The sap of the mango tree contains a substance similar to that causing the familiar rash of poison ivy, oak and sumac. This sticky substance sometimes gets onto the skin of the mango and, once getting onto your skin, can cause an allergic reaction of itching, redness and blisters, resembling poison ivy.

Besides mangos, other plants sharing an allergic substance related to poison ivy are cashew nuts -- the oil in the shell is the culprit -- and the Japanese lacquer tree, whose resin is used to varnish wood.

As long as you avoid coming into contact with mango sap, you shouldn't have any problem enjoying your favorite fruit. But you can't remedy your problem by simply washing a mango before eating it, because once the sap gets on the skin it binds to it and can't be completely washed off.

One solution: Ask someone else to remove the skin for you. Follow-up: Postpartum Depression

Q. After reading your recent discussion about depression, I wanted to ask about my problem. I'm 24 and had a healthy baby girl five months ago. Shortly after delivery, I began having overwhelming feelings of depression. I didn't feel like doing anything, cried a lot and even felt resentful toward my baby, though I love her deeply. I've heard about getting "the blues" after pregnancy, but wonder if my reaction was normal. I'm just now gradually coming out of it.

A. It's true that many women feel a little "down in the dumps" for a day or two shortly after delivery, but it sounds as if your experience was more severe than may normally occur.

The cause of postpartum depression -- the medical term for this condition -- isn't clear. Different theories suggest that this disorder is triggered by 1) changes in hormone levels and other physical changes following delivery, 2) the stress of delivery itself or 3) the demands of taking care of a new baby.

If you have any of the following symptoms, your reaction is probably out of the ordinary and I recommend discussing how you're feeling with your doctor: Symptoms of depression that are more than just feeling mildly blue or tired. These include 1) feeling listless and not feeling like doing anything, especially if you neglect taking proper care of your baby or yourself; 2) feeling very sad or having uncontrollable crying spells; 3) having difficulty sleeping, or sleeping too much -- aside from the expected changes in sleep that accompany taking care of a newborn; and 4) having changes in your appetite, especially losing your taste for foods. Any of the above depressive symptoms lasting more than a week or so. Depression associated with changes in your personality, suicidal thoughts or feeling out of touch with reality. Feeling urges to harm your baby, your other children or yourself.

Depending on how severe your symptoms are, your doctor may try counseling you in the office or refer you for psychiatric counseling, with or without antidepressant medications. Because your symptoms after your recent delivery were both very troublesome and lasted a long time, I recommend letting your doctor know about your reaction if you become pregnant again. Earlier treatment would probably have helped you get over your postpartum depression sooner.

Jay Siwek, a family physician from Georgetown University, practices at the Fort Lincoln Family Medicine Center and Providence Hospital in Northeast Washington.

Consultation is a health education column and is not a substitute for medical advice from your physician. Send questions to Consultation, Health Section, The Washington Post, 1150 15th St. NW, Washington, D.C. 20071. Questions cannot be answered individually.