Let’s see you pull that out of my back!

HISTORY
This 50-year-old man first noticed a bulge in his low back several years ago. Every time he brings it to the attention of his medical providers, he is told it is, and will remain, benign and that the best thing he can do is leave it alone.

But it finally grows to a bothersome size, causing pain at times—such as when he leans against hard surfaces—and actually becoming visible under certain clothes. And so he seeks evaluation from a dermatology provider.

His health is otherwise excellent, with no family history of such lesions and no personal history of similar manifestations elsewhere on his body.

EXAMINATION
An ill-defined subcutaneous mass is felt in the L4 area of the patient’s mid-low back; no overlying skin changes can be seen or felt. The mass is rubbery, with a smooth surface, and not at all tender to palpation. The patient’s skin is otherwise free of such lesions.

PROCEDURE
After a thorough discussion of the options available to this patient, the decision is made to excise the lesion. As is customary, this conversation includes disclosure of the anticipated procedure (excision), the indications for the procedure, alternatives, and risks involved in removal.

Under local anesthesia (1% lidocaine with epinephrine) and sterile conditions, a horizontal incision is made. This effectively creates an elliptical window through which the lesion can be visualized, freed by blunt dissection, and then removed in one large piece, which turns out to be in excess of 6 cm—larger than anticipated.

The lesion is consistent in every way with the anticipated diagnosis of lipoma, including the presence of the expected “capsule” (extremely thin web of connective tissue) surrounding the tumor. The defect’s size and depth require three layers to close it, leaving the patient with a 5-cm transverse wound. As is always the case with excised lesions, this one is sent for pathologic examination, which confirms the diagnosis.

DISCUSSION
Obviously, the presentation and history of this lesion were quite consistent with an extremely common diagnosis: lipoma. The other main item in the differential is epidermal cyst, although additional diagnostic possibilities include liposarcoma, glomus tumor, and leiomyoma.

Lipomas are the most common tumor of mesenchymal origin. They are composed of mature fat cells, but differ from normal fat by the demonstration of increased levels of lipoprotein lipase and by the presence of larger numbers of precursor cells.

Lipomas can appear almost anywhere—including internal organs and even the spinal cord—though most commonly, by far, in subcutaneous locations on the trunk and extremities. As in this case, they come to the patient’s attention because of growth or discomfort (or both).

Occasionally, lipomas, even after several years, become painful, and on removal may prove to be a benign innervated variant called angiolipoma. While many other subtypes exist, the vast majority is completely benign. Obviously, rapid growth or other change could signal malignant transformation.

Lipomas are often seen in the context of an inherited condition in which multiple asymptomatic lipomas appear in the third decade of life, usually in forearms and thighs. Termed familial benign lipomatosis, its mode of inheritance is autosomal dominance.

Protease inhibitors given for HIV can cause lipodystrophy of several types, including the appearance of lipomas, as well as the well-known buccal atrophy.

Had this patient’s lipoma undergone rapid growth or had it been accompanied by other significant findings (the so-called fawn’s tail, a tuft of hair, unusual tags, hemangiomas and others in the sacral region), it might well have required pre-operative imaging to rule out spinal dysraphism or other occult embryonic malformation.

This patient made a rapid and uneventful recovery from his surgery. Complications could have included hematoma formation, infection, bleeding, or dysfunctional scarring.

TAKE-HOME LEARNING POINTS
• Lipomas are extremely common and are often seen in the context of an inherited trait called benign familial lipomatosis.

• Epidermal cysts and lipomas can present in similar fashion, though the cysts tend to be more firm and have an overlying punctum. Lipomas tend to be more rubbery and have no overlying punctum.

• Lipomas can be found almost anywhere in the body, including internally.

• Lipomas frequently prove to be larger on removal than would be expected from outward appearance.

• With large lipomas in certain locations—such as in the medial epicondylar area, deep in the forehead, in the scalp, or in the upper trapezius area, for example—consider referral to a surgeon.

HISTORY
This 50-year-old man first noticed a bulge in his low back several years ago. Every time he brings it to the attention of his medical providers, he is told it is, and will remain, benign and that the best thing he can do is leave it alone.

But it finally grows to a bothersome size, causing pain at times—such as when he leans against hard surfaces—and actually becoming visible under certain clothes. And so he seeks evaluation from a dermatology provider.

His health is otherwise excellent, with no family history of such lesions and no personal history of similar manifestations elsewhere on his body.

EXAMINATION
An ill-defined subcutaneous mass is felt in the L4 area of the patient’s mid-low back; no overlying skin changes can be seen or felt. The mass is rubbery, with a smooth surface, and not at all tender to palpation. The patient’s skin is otherwise free of such lesions.

PROCEDURE
After a thorough discussion of the options available to this patient, the decision is made to excise the lesion. As is customary, this conversation includes disclosure of the anticipated procedure (excision), the indications for the procedure, alternatives, and risks involved in removal.

Under local anesthesia (1% lidocaine with epinephrine) and sterile conditions, a horizontal incision is made. This effectively creates an elliptical window through which the lesion can be visualized, freed by blunt dissection, and then removed in one large piece, which turns out to be in excess of 6 cm—larger than anticipated.

The lesion is consistent in every way with the anticipated diagnosis of lipoma, including the presence of the expected “capsule” (extremely thin web of connective tissue) surrounding the tumor. The defect’s size and depth require three layers to close it, leaving the patient with a 5-cm transverse wound. As is always the case with excised lesions, this one is sent for pathologic examination, which confirms the diagnosis.

DISCUSSION
Obviously, the presentation and history of this lesion were quite consistent with an extremely common diagnosis: lipoma. The other main item in the differential is epidermal cyst, although additional diagnostic possibilities include liposarcoma, glomus tumor, and leiomyoma.

Lipomas are the most common tumor of mesenchymal origin. They are composed of mature fat cells, but differ from normal fat by the demonstration of increased levels of lipoprotein lipase and by the presence of larger numbers of precursor cells.

Lipomas can appear almost anywhere—including internal organs and even the spinal cord—though most commonly, by far, in subcutaneous locations on the trunk and extremities. As in this case, they come to the patient’s attention because of growth or discomfort (or both).

Occasionally, lipomas, even after several years, become painful, and on removal may prove to be a benign innervated variant called angiolipoma. While many other subtypes exist, the vast majority is completely benign. Obviously, rapid growth or other change could signal malignant transformation.

Lipomas are often seen in the context of an inherited condition in which multiple asymptomatic lipomas appear in the third decade of life, usually in forearms and thighs. Termed familial benign lipomatosis, its mode of inheritance is autosomal dominance.

Protease inhibitors given for HIV can cause lipodystrophy of several types, including the appearance of lipomas, as well as the well-known buccal atrophy.

Had this patient’s lipoma undergone rapid growth or had it been accompanied by other significant findings (the so-called fawn’s tail, a tuft of hair, unusual tags, hemangiomas and others in the sacral region), it might well have required pre-operative imaging to rule out spinal dysraphism or other occult embryonic malformation.

This patient made a rapid and uneventful recovery from his surgery. Complications could have included hematoma formation, infection, bleeding, or dysfunctional scarring.

TAKE-HOME LEARNING POINTS
• Lipomas are extremely common and are often seen in the context of an inherited trait called benign familial lipomatosis.

• Epidermal cysts and lipomas can present in similar fashion, though the cysts tend to be more firm and have an overlying punctum. Lipomas tend to be more rubbery and have no overlying punctum.

• Lipomas can be found almost anywhere in the body, including internally.

• Lipomas frequently prove to be larger on removal than would be expected from outward appearance.

• With large lipomas in certain locations—such as in the medial epicondylar area, deep in the forehead, in the scalp, or in the upper trapezius area, for example—consider referral to a surgeon.

HISTORY
This 50-year-old man first noticed a bulge in his low back several years ago. Every time he brings it to the attention of his medical providers, he is told it is, and will remain, benign and that the best thing he can do is leave it alone.

But it finally grows to a bothersome size, causing pain at times—such as when he leans against hard surfaces—and actually becoming visible under certain clothes. And so he seeks evaluation from a dermatology provider.

His health is otherwise excellent, with no family history of such lesions and no personal history of similar manifestations elsewhere on his body.

EXAMINATION
An ill-defined subcutaneous mass is felt in the L4 area of the patient’s mid-low back; no overlying skin changes can be seen or felt. The mass is rubbery, with a smooth surface, and not at all tender to palpation. The patient’s skin is otherwise free of such lesions.

PROCEDURE
After a thorough discussion of the options available to this patient, the decision is made to excise the lesion. As is customary, this conversation includes disclosure of the anticipated procedure (excision), the indications for the procedure, alternatives, and risks involved in removal.

Under local anesthesia (1% lidocaine with epinephrine) and sterile conditions, a horizontal incision is made. This effectively creates an elliptical window through which the lesion can be visualized, freed by blunt dissection, and then removed in one large piece, which turns out to be in excess of 6 cm—larger than anticipated.

The lesion is consistent in every way with the anticipated diagnosis of lipoma, including the presence of the expected “capsule” (extremely thin web of connective tissue) surrounding the tumor. The defect’s size and depth require three layers to close it, leaving the patient with a 5-cm transverse wound. As is always the case with excised lesions, this one is sent for pathologic examination, which confirms the diagnosis.

DISCUSSION
Obviously, the presentation and history of this lesion were quite consistent with an extremely common diagnosis: lipoma. The other main item in the differential is epidermal cyst, although additional diagnostic possibilities include liposarcoma, glomus tumor, and leiomyoma.

Lipomas are the most common tumor of mesenchymal origin. They are composed of mature fat cells, but differ from normal fat by the demonstration of increased levels of lipoprotein lipase and by the presence of larger numbers of precursor cells.

Lipomas can appear almost anywhere—including internal organs and even the spinal cord—though most commonly, by far, in subcutaneous locations on the trunk and extremities. As in this case, they come to the patient’s attention because of growth or discomfort (or both).

Occasionally, lipomas, even after several years, become painful, and on removal may prove to be a benign innervated variant called angiolipoma. While many other subtypes exist, the vast majority is completely benign. Obviously, rapid growth or other change could signal malignant transformation.

Lipomas are often seen in the context of an inherited condition in which multiple asymptomatic lipomas appear in the third decade of life, usually in forearms and thighs. Termed familial benign lipomatosis, its mode of inheritance is autosomal dominance.

Protease inhibitors given for HIV can cause lipodystrophy of several types, including the appearance of lipomas, as well as the well-known buccal atrophy.

Had this patient’s lipoma undergone rapid growth or had it been accompanied by other significant findings (the so-called fawn’s tail, a tuft of hair, unusual tags, hemangiomas and others in the sacral region), it might well have required pre-operative imaging to rule out spinal dysraphism or other occult embryonic malformation.

This patient made a rapid and uneventful recovery from his surgery. Complications could have included hematoma formation, infection, bleeding, or dysfunctional scarring.

TAKE-HOME LEARNING POINTS
• Lipomas are extremely common and are often seen in the context of an inherited trait called benign familial lipomatosis.

• Epidermal cysts and lipomas can present in similar fashion, though the cysts tend to be more firm and have an overlying punctum. Lipomas tend to be more rubbery and have no overlying punctum.

• Lipomas can be found almost anywhere in the body, including internally.

• Lipomas frequently prove to be larger on removal than would be expected from outward appearance.

• With large lipomas in certain locations—such as in the medial epicondylar area, deep in the forehead, in the scalp, or in the upper trapezius area, for example—consider referral to a surgeon.