Derm Dx: Lumps and bumps on a patient's back - Clinical Advisor

Derm Dx: Lumps and bumps on a patient’s back

Slideshow

  • Nevus Liposomatus 1_0113 Derm Dx

  • Nevus Lipomatosus 2_0113 Derm Dx

A 38-year-old woman presents complaining of “lumpy, bumpy” skin on her lower back that has been present for as long as she can remember. It is asymptomatic, but very embarrassing.

The patient is otherwise healthy. A complete physical exam reveals that she is overweight. She has no other skin lesions or other significant findings.

Nevus lipomatosus is a benign lesion that is classified as a hamartoma, or connective tissue nevus. It consists of clusters of soft papules and nodules most commonly on the hip and buttocks.  Nevus lipomatosus lesions are frequently present at birth...

Submit your diagnosis to see full explanation.

Nevus lipomatosus is a benign lesion that is classified as a hamartoma, or connective tissue nevus. It consists of clusters of soft papules and nodules most commonly on the hip and buttocks. 

Nevus lipomatosus lesions are frequently present at birth or may develop during the first two decades of life. Men and women are equally affected. The pathogenesis is unknown.

Normally, the dermis does not contain fat. However, in nevus lipomatosus mature fat is present in the superficial reticular dermis, leading to the development of soft and lumpy lesions. This patient’s exam and history was not consistent with any of the other syndromes listed. 

Goltz syndrome, also called focal dermal hypoplasia, is attributable to defects in the PORCN gene. The inheritance is X-linked dominant, so the vast majority of patients with are female. 

In Goltz syndrome there are abnormalities in the mesodermal and ectodermal tissues.  Specific findings include atrophic erythematous streaks in a Blaschkoid distribution, papillomas in a perioral and perianal distribution, ocular coloboma and syndactyly.

Proteus syndrome is characterized by asymmetric limb and soft tissue overgrowth.  Specific findings include asymmetric gigantism of limbs and digits, linear verrucous epidermal nevi, vascular malformation, lipomas, visceral hamartomas and cerebriform hyperplasia of the palms or soles.  

Cowden syndrome is an autosomal dominant disorder caused by mutations in the PTEN tumor suppressor gene.  Patients develop multiple mucocutaneous lesions including trichilemmomas, oral papillomas, acral keratoses, sclerotic fibromas, lipomas, hemangiomas, and acanthosis nigricans. Macrocephaly is present in 97% of patients.   Malignancies develop in 40% of patients, especially breast, thyroid, and endometrial cancers. 

Diagnosis & Treatment

Nevus lipomatosus superficialis can be suspected on clinical grounds, and is confirmed by a biopsy demonstrating mature fat in the superficial dermis.  Treatment is surgical excision.           

Adam Rees, MD, is a graduate of the University of California Los Angeles School of Medicine and a resident in the Department of Dermatology at Baylor College of Medicine in Houston.

References

  1. Bolognia J, Jorizzo JL, Rapini RP. Dermatology. Chapters 61, 62, 117. St. Louis, Mo.: Mosby/Elsevier, 2008.
  2. James WD, Berger TG, Elston DM et al. Andrews’ Diseases of the Skin: Clinical Dermatology. Chapters 28 and 29. Philadelphia: Saunders Elsevier, 2006.
Next hm-slideshow in Clinical Quiz