Question

A 67-year-old female with history of Stage IIB multifocal left breast cancer presented with lesions on the left trunk for the past 3 months. She underwent left nipple sparing mastectomy, left axillary lymph node dissection, right prophylactic mastectomy, and radiation and was currently on anastrazole. Her breast cancer was under remission at onset of presentation. Lesions were located at sites where she had prior radiation treatment, but also included untreated areas. She admitted to sporadic pruritus and a burning sensation. On exam there were numerous well-defined spiny follicular keratotic skin-colored papules on left chest, axillae, neck, and lateral arm (Image 1). A shave biopsy of the left chest was performed (Images 2,3).

Based upon the patient history, clinical examination, and histopathologic findings, what is the most likely diagnosis?

1. Follicular spicules
2. Trichodysplasia spinulosa
3. Lichen spinulosus
4. Phrynoderma
5. Trichostasis spinulosa

Correct Answer

Correct Answer: (1) Follicular spicules

Explanation

Follicular spicules (correct answer A) are a rare cutaneous finding characterized by small, skin-colored to white or yellow hyperkeratotic thin papules or spines emerging from hair follicles. They are typically located on the face, primarily the nose, however, can also be found on the extremities or trunk. Follicular spicules are often the preceding cutaneous sign of multiple myeloma, although, they can be drug-induced and have been found to be associated with inflammatory, autoimmune and infectious etiologies such as Crohn’s disease, systemic lupus erythematosus, dermatomyositis, and HIV. When follicular spicules occur in relation to polyomavirus, they are termed trichodyplasia spinulosa (answer B).

Follicular spicules can be a presenting sign of malignancy, including breast cancer. Few case reports reveal multiple spiny papules occurring over breast masses and breast changes associated with invasive ductal carcinoma. It is unclear if these spicules improve or resolve following breast cancer treatment. Follicular spicules may also be associated with radiation therapy, including radiation-recall, where skin findings occur following the administration of radiation or chemotherapeutic agents. In several case reports, follicular spicules were located at the site of radiation six months to a year following the last treatment. Skin biopsy typically shows evidence of both radiation dermatitis and follicular spicules and cutaneous findings resolved with use of topical steroids and emollients.

Lichen spinulosus (answer C) is characterized by follicular hyperkeratotic papules more common in pediatric patients with a history of atopy. Most cases of lichen spinulosus resolve spontaneously around puberty. Phrynoderma (answer D) can be seen in vitamin A deficiency and characterized by hyperkeratotic follicular papules on the extensor surfaces. In vitamin A deficiency typically there will be additional features such as night blindness, diarrhea, blepharitis, Bitot spots, and neuritis. Trichostasis spinulosa (answer E) presents with follicular hyperkeratosis overlying multiple tiny vellus hairs commonly on the nose. These lesions are generally asymptomatic and do not warrant treatment unless symptomatic or for cosmetic purposes.

References

1. Schwartz RA, Fernandez G, Kotulska A. Follicular spicules as a cutaneous marker of systemic disease. Cutis. 2016 Sep;98(3):E15-8. PMID: 27741353.
2. Cheng YP, Wu CJ, Huang YC, Lee CH, Lee CY. Trichodysplasia spinulosa in a patient with acquired immunodeficiency syndrome. Int J Dermatol. 2014 Nov;53(11):e516-8. PMID: 25278084.
3. Bower JH, Christenson LJ, Howe BM, et al. Cutaneous markers of breast cancer: morphologic, immunohistochemical, and molecular genetic features. Am J Dermatopathol. 2015 Feb;37(2):137-43. PMID: 25029109.
4. Nangia C, Liu M, Reynolds R, et al. Radiation recall dermatitis presenting as follicular spicules in a patient with breast cancer. Case Rep Oncol Med. 2014;2014:524754. PMID: 25243141.