Monika Knickenberg

Dr med Monika Knickenberg

Monika Knickenberg is a German dermatopathologist.

Knickenberg worked with Prof. Dr. med. Otto P. Hornstein University Hospital of Erlangen, Germany. In 1975 they reviewed a 47-year-old referred for evaluation of numerous benign-looking skin tumours following the surgical removal of multiple polyps of the colon, including one colon carcinoma.

Over three publications in 1975 and 1976 they described a new autosomal dominant trait genodermatosis characterized by ‘perifollicular fibromatosis cutis’, heralding extracutaneous cancer proneness – Hornstein-Knickenberg syndrome (HKS)

  • Universität Marburg
  • Universität Ulm
  • Dermatologische Universitätsklinik, Erlangen, BRD
  • Abteilung für Dermatologie der Universität Ulm

Medical Eponyms
Hornstein-Knickenberg syndrome (HKS)(1975)

In 1975, Otto Hornstein (1926–2018) and Knickenberg described the syndrome of multiple perifollicular fibromas heralding extracutaneous cancer proneness and being inherited as an autosomal dominant trait.

Hornstein-Knickenberg syndrome 1975
Densely aggregated flat-topped papules interspersed with multiple skin tags on neck and shoulders. Hornstein, Knickenberg 1975: 164

Hornstein published an article in 1976 highlighting this ‘rare, generalized genodermatosis’ and a further paper in 1976, with Knickenberg and Mörl highlighting that multiple perifollicular fibromas may herald the presence of colonic polyposis.

We are prone to assume that the (irregular ?) association of multiple perifollicular fibromas and colon polyps represents a distinct nosological entity neither identical with Gardner’s syndrome nor with any other known dermo-intestinal syndrome. Thus, perifollicular fibromatosis should alert the dermatologist to consider periodic thorough examination for intestinal polyps the more as they may change into malignant growth.

Hornstein, Knickenberg 1975: 161

Major Publications


The autosomal dominant inherited syndromes of Hornstein-Knickenberg (HKS) and Birt-Hogg-Dubé (BHDS) are both characterized clinically by the presence of multiple flesh coloured papules of the skin. Hornstein and Knickenberg termed the peripheral lesions of HKS ‘perifollicular fibromas’ whilst Birt, Hogg and Dubé proposed the name ‘fibrofolliculoma’.

The nosological dilemma is twofold:

  • Many authors believe that perifollicular fibromas and fibrofolliculomas are one and the same, and not a reason to suppose that the condition described by Birt, Hogg and Dubé (1977) was a new disorder from that originally described by Hornstein and Knickenberg (1975)
  • The importance of ‘extracutaneous cancer proneness’, was postulated in all three papers by Hornstein, but not in the 1977 of Birt, Hogg and Dubé. Numerous authors have corroborated the association between multiple perifollicular fibromas and colonic polyps/cancer as Hornstein and Knickenberg suggested.

Prof Dr Rudolf Happle of the Department of Dermatology, at the University of Freiburg staunchly moved for a name change in 2012, and again in 2020

Birt et al. did neither discover nor describe any new cutaneous disorder heralding proclivity to extracutaneous cancer. Hence, the term ‘Birt-Hogg-Dubé syndrome’ represents a bold distortion of history and should no longer be used to describe the disorder specified by Hornstein and Knickenberg…it is not justified to combine the names of the discoverers of a new genodermatosis heralding extracutaneous cancer proneness with those claiming that they had detected a quite different hereditary skin disorder characterized by ‘fibrofolliculomas’, without any proclivity to extracutaneous cancer…Today, time has come to put this right. The syndrome should be named after the original authors, Hornstein and Knickenberg

Happle 2020


BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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