It is a well-known fact that trainees in Dermatology & Dermatopathology are overawed by the hundreds and thousands of entities in our field, particularly with a new entity being named on a weekly basis!

For a novice in the field, the prospect of getting to terms with these entities is daunting and is probably one of the reasons most dermatologists are happy to outsource pathology to someone else. How many of these entities are actually truly unique and how many of these can be 'lumped' together into the same spectrum?

Expert 'Splitters' continue to argue that entities like Lichen Sclerosus & Morphoea have nothing in common whilst expert 'lumpers' argue the other way around. I am personally a 'lumper', as long as lumping the entities, has no adverse clinical/ prognostic/ therapeutic significance. However, this can become very controversial when it comes to entities like Keratoacanthoma & 'well-differentiated' SCC.

The reason I am blogging on this issue is that, we had recently come across a unique case of a cellular fibrous histiocytoma with Touton giant cells. An exactly similar case was published in the Am J Dermpath and described as a Spindle cell Xanthogranuloma with hemosiderin [1]. Further reading into the topic, confirmed my impression that Fibrous Histiocytoma (Dermatofibroma) and Xanthogranuloma are part of the same spectrum, when in fact these are described in completely different unrelated chapters in most dermpath textbooks! The fact that these are related entities and part of the same spectrum has already been proposed by a number of authors [2-4]. This is nothing new, but has not made it into any if the main text books!

Why do we like to make things more complicated than they are/ need to be? What purpose does it serve apart from scaring away folk even remotely interested in dermpath? I think we seriously need to introspect and try and make the speciality as simple as possible. I hope someone takes this task up in future. Before describing a new entity, one has to make all efforts to see if one can fit this into a variant of existing known entities.

As an exercise for fun , have a look at the list below and comment if you think they have anything in common:
[list]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Facial idiopathic granulomas with regressive evolution[/size][/color][/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Acnitis[/size][/color][/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Granulomatous Rosacea[/size][/color][/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Peri-oral dermatitis[/size][/color][/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Peri-orificial dermatitis[/size][/color][/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Acne Agminata[/size][/color][/font]
[*][font=verdana,geneva,sans-serif]Childhood granulomatous periorificial dermatitis[/font]
[*][font=verdana,geneva,sans-serif][color=#000000][size=3]Facial Afro-Caribbean childhood eruption[/size][/color][/font]
[/list]

[b]References:[/b]

1. Nakamura Y, Nakamura A, Muto M. Solitary spindle cell xanthogranuloma mimicking a spitz nevus. [i]Am J Dermatopathol[/i] 2013; 35: 865-867

2. Misery L, Boucheron S, Claudy AL. Factor XIIIa expression in juvenile xanthogranuloma. Acta Derm Venereol 1994; 74: 43-44

3. Niemi KM. Acta Derm Venereol Suppl (Stockh). 1970;50(63):Suppl 63:1-66. The benign fibrohistiocytic tumours of the skin.

4. Sachdev R, Sundram U. J Cutan Pathol. 2006 May;33(5):353-60. Expression of CD163 in dermatofibroma, cellular fibrous histiocytoma, and dermatofibrosarcoma protuberans: comparison with CD68, CD34, and Factor XIIIa.