UPMC Dermatopathology "Case of the Month" Presentations
UPP - Department of Dermatology, Dermatopathology Unit
Case Authors: Maria F. Rueda, MD , Douglas Kress, MD, Drazen M. Jukic, MD,PhD,
DECEMBER 2003 CASE OF THE MONTH
DISCUSSION & DIAGNOSIS
We interpreted the patient's lesion as a case of Primary Follicular Mucinosis. Follicular Mucinosis (also called first Alopecia mucinosa, Pinkus, 1957) is part of the cutaneous mucinoses. It presents as plaques resulting of the coalescence of pink-yellow-white small follicular papules that may result in alopecia due to degeneration of the hair follicles. Lesions are variably pruritic. 1. A sticky substance exudating from the hair follicles is occasionally observed. This substance has been identified as the acid glycoprotein mucin 2. Histopathology reveals a variably dense dermal and perifollicular infiltrate of lymphocytes with admixed occasional histiocytes and eosinophils. In the outer sheath of the hair follicle, around it, and in some cases involving the sebaceous gland , there are collections of acid mucopolysaccharides 3. This substance is PAS-D and Alcian Blue positive, and colloidal stain positive. It is easy to diagnose but is difficult to differentiate between the benign variant (commonly called Pinkus variant) and the Mycosis Fungoides variant. Clues to favor the benign type (Rongioletti et al) are: large amount of mucin, a mainly follicular, perifollicular and perivascular inflammatory infiltrate rather than a more diffuse and nodular one, many eosinophils, few plasma cells, slight or absent epidermotropism without atypical cells, absence of a T-cell receptor rearrangement 8. There is no consensus in the definition and prognosis pathognomonic of FM.
Histopathologic features of the 'benign" type and the mycosis fungoides type
show overlap and the clinical features are not in either case. A clinic pathological
correlation of the patient's age, location of the lesions, solitary vs. multiple
lesions, the amount of mucin, the density of the infiltrate, and the clonality
may yield a more accurate diagnosis. Histopathologic features of the 'benign'
type and the 'CTCL associated' type show overlap but the clinical features can
usually distinguish them. However, the controversy continues and the patients
should be instructed to return to the clinic for routine skin exams and anytime,
if a new rash develops. We want to thank Loren Funt, MD, Dermatologist, Private Practice, Pittsburgh,
PA who assists in the teaching of the residents and brought up the differential
diagnoses of Eczema vs Follicular Mucinosis.
The classification of these lesions has always been controversial and confuse because lesions diagnosed as Follicular Mucinosis (FM) of the benign type were found to result in lymphoma, suggesting either a transformation or more likely theses were cases of Mycosis Fungoides since the beginning 9.
Three clinical variants may be described:
1) Localized Benign FM: Few benign plaques on the head or neck or arms of kids and young adults, that resolves spontaneously in few months to years. This variant is the most common and it has been called Alopecia mucinosa , primary follicular mucinosis, idiopathic follicular mucinosis and benign follicular mucinosis.
2) Generalized Benign FM: Benign more widespread lesions in older individuals that may recur indefinitely. These lesions may be associated to other underlying disorders such as lichen planus, sarcoidosis, lupus, angiolymphoid hyperplasia with eosinophilia, Kaposi Sarcoma, Familial reticuloendotheliosis , Hodgkin's lymphoma and leukemia. Pseudolymphoma and pityrosporum folliculitis may also exhibit mucin 1.2.3,8 . There are new reports of association with Cutaneous Leishmaniasis 4 and Squamous cell carcinoma of the tongue 5.
3) CTCL associated FM: Older patients with alopecic or non-alopecic lesions that represent a type of Cutaneous T cell Lymphoma, specifically Mycosis Fungoides. These cases account for around 30% of the cases of follicular mucinosis. Tumor cells are present in the follicular epithelium , epidermis or dermis 1. Van Doorn et al proposed to call it Follicular Mycosis Fungoides with associated mucinosis 10. For the EORTC (European Organization for Research on the Treatment of Cancer) it is considered a subtype of Mycosis fungoides 10. The prognosis of these lesions is good as it is the prognosis of circumscribed lesions of Mycosis Fungoides 9.
Therapeutic options include topical and systemic PUVA and UVA1 cold light 6, topical and intralesional steroids, Minocycline 7 and in more severe cases Topical Nitrogen Mustard, Dapsone, Indomethacin, Retinoids, Electron Beam Therapy, Radiation , Chemotherapy and Interferon alpha 2b. 1,2,3.
REFERENCES:
1. Fitzpatrick's Dermatology in General Medicine. 5th ed. New York, NY: McGraw-Hill; 1999.
2. Rook A, Wilkinson DS, Ebling FJG: Textbook of Dermatology. Vol 2. Oxford: Blackwell Scientific 1998.
3. Andrews GC et al: Andrew's Diseases of the Skin. 8th ed. Philadelphia: WB Saunders 1990
4. Abajo P, Martin R, Dauden E .Follicular mucinosis associated with cutaneous leishmaniasis. Acta Derm Venereol 1998 Jul;78(4):315
5. Walchner M, Messer G, Rust A, Sander C, Rocken M. Follicular mucinosis in association with squamous cell carcinoma of the tongue. J Am Acad Dermatol 1998 Apr;38(4):622-4
6. Von Kobyletzki G, Kreuter JA, Nordmeier R, Stucker M, Altmeyer P. Treatment of idiopathic mucinosis follicularis with UVA1 cold light phototherapy. Dermatology 2000;201(1):76-7
7. Yotsumoto S, Uchimiya H, Kanzakaki T. A case of follicular mucinosis treated successfully with minocycline. Br J Derm 142: 841-842.
8. Rongioletti F, Rebora A.Cutaneous Mucinoses: microscopic criteria for diagnosis. Am J Dermatopathol 2001 Jun;23(3):257-67
9. Cerroni L, Fink-Puches R, Back B, Kerl H. Follicular Mucinosis. Arch Dermatol 2002;138:182-189.
10. Van Doorn R, Scheffer E, Willemze R. Follicular mycosis fungoides, a distinct disease entity with or without associated follicular mucinosis. Arch Dermatol 2002;138:191-198.
