A 52-year-old black woman presented with a 5-year history of gradual swelling and slowed hair growth involving the vertex and both parietal regions of the scalp. Gradually, the swelling progressed to involve the entire scalp, only sparing a peripheral crown. She reported no history of trauma or medications. Slight pruritus of the involved area was the only accompanying symptom. There was no family history of a similar condition. Her past medical history included surgery for ovarian cysts, 10 years previously, and cholelithiasis.
Physical examination revealed diffuse hair thinning and alopecia, more prominent along the vertex and parietal regions (Fig. 1a). There was no evidence of scalp inflammation, scaling, or increased hair fragility. The scalp was mildly tender on palpation and had a boggy, spongy consistency. The hairs which still remained in the involved areas were thin, short, and soft (Fig. 1b). The involved area was slightly hypopigmented when compared with adjacent noninvolved scalp. The rest of the physical examination was within normal limits. No abnormalities of the hair shaft were observed on microscopic examination of several plucked hairs. Laboratory investigations, including a complete blood cell count, blood chemistry, urinalysis, sedimentation rate, antinuclear antibodies, and serologic tests for syphilis, hepatitis B and C virus, and human immunodeficiency virus, were negative. A computed tomography scan of the skull demonstrated diffuse and regular thickening of subcutaneous fatty tissue of the scalp, disclosing a maximum scalp thickness of 15 mm at the vertex (Fig. 2).
The biopsy from the vertex revealed a normal epidermis and dermis, with diffuse loss of hair follicles. The most striking feature consisted of a large increase in thickness of the subcutaneous fatty tissue (Fig. 3a). Pre-existing hair follicles were replaced by vertical fibrous tracts of lamellar fibroplasia with no inflammatory infiltrate (Fig. 3b). Adipocytes showed a normal size and shape, but the connective tissue septa, which are normally present separating the subcutaneous tissue into fat lobules, were lacking, and subcutaneous fatty tissue consisted of a continuous and diffuse sheet of mature adipocytes (Fig. 3c). Orcein stain revealed normal contents of elastic fibers with foci of condensation at the sites of disappeared pre-existing hair follicles (Fig. 3d). Colloidal iron and Alcian blue (pH 2.5) stains revealed no mucin deposits.