Case Number : Case 2976 - 2 December 2021 Posted By: Saleem Taibjee

Probably involvement by the patient's known CMML. Need IHC to confirm.

There's rather a lot of abnormality in the stratum corneum for leukaemia cutis.  Combined with the clinical pictures, I would be wondering about extensive Candidiasis and would like to see a PAS stain.  Also, eosinophils are conspicuous in the infiltrate, so a drug reaction would need to be considered.

14 hours ago, sfwenson said:

Probably involvement by the patient's known CMML. Need IHC to confirm.

To me cells appear like Langerhans cell. Could it be Langerhans or indeterminate cell histiocytosis.  There also appear to be some atypical cells which could be atypical Langerhans cells itself or myeloid cells. There are reports of Langerhans cells histiocytosis and Langerhans cell sarcoma, as well as Indeterminate cells histiocytosis associated with myeloid leukemia, in one report both types Langerhans and myeloid cells coexisted in cutaneous lesions. 

1. Yohe SL, Chenault CB, Torlakovic EE, Asplund SL, McKenna RW. Langerhans cell histiocytosis in acute leukemias of ambiguous or myeloid lineage in adult patients: support for a possible clonal relationship. Mod Pathol. 2014 May;27(5):651-6.

2. Pina-Oviedo S, Torres-Cabala CA, Miranda RN, Tetzlaff MT, Singh S, Rapini RP, Prieto VG, Aung PP. Concomitant Cutaneous Langerhans Cell Histiocytosis and Leukemia Cutis. Am J Dermatopathol. 2017 May;39(5):388-392.

agree, it is interesting case

Histiocytic infiltrates in Myeloid leukemia

other thing is Myeloid Neoplasms with Elevated Plasmacytoid Dendritic Cell Differentiation with skin lesions

IHC is panel is needed

On 02/12/2021 at 08:39, Meenakshi Batrani said:

To me cells appear like Langerhans cell. Could it be Langerhans or indeterminate cell histiocytosis.  There also appear to be some atypical cells which could be atypical Langerhans cells itself or myeloid cells. There are reports of Langerhans cells histiocytosis and Langerhans cell sarcoma, as well as Indeterminate cells histiocytosis associated with myeloid leukemia, in one report both types Langerhans and myeloid cells coexisted in cutaneous lesions. 

 

1. Yohe SL, Chenault CB, Torlakovic EE, Asplund SL, McKenna RW. Langerhans cell histiocytosis in acute leukemias of ambiguous or myeloid lineage in adult patients: support for a possible clonal relationship. Mod Pathol. 2014 May;27(5):651-6.

2. Pina-Oviedo S, Torres-Cabala CA, Miranda RN, Tetzlaff MT, Singh S, Rapini RP, Prieto VG, Aung PP. Concomitant Cutaneous Langerhans Cell Histiocytosis and Leukemia Cutis. Am J Dermatopathol. 2017 May;39(5):388-392.

I was about to write that in my opinion, in the absence of a clinical history, it was LCH. Then I saw Meenakshi's comment, which I am in tune with. 

It needs IHC, of course, as CD1a Langherine CD4 CD56 CD123 CD34 CD11c CD14 CD68. 

The clinical picture suggests candidiasis. I think that this is leukemia cutis with superadded candidiasis. Would suggest myeloperoxidase stain in addition to those suggested by Vincenzo.

I think i recall this case presented elsewhere and LCH was the diagnosis? 

This is a patient from our hospital only seen in the past few weeks. The histology has not been presented elsewhere. I will allow more people to respond before showing the immunostains and revealing the answer.

Furthermore epidermotropism is typical of Langherans cells...so my first spot, without immune, is LCH. Another diff could be an exceedingly strong reaction as allergic contact dermatitis, but never seen so many lang-cells. Waiting for the answer.  

The immunos are shown below.

This is a very recent case which I reported at our local hospital of Langerhans cell histiocytosis which is quite rare overall, but especially in adults. It is the first case I have seen since working in Dorset over the past 8 years or so.

As Vincenzo points out, the epidermotropism is a very good clue. Here the infiltrate is really too dense for this to be reactive (Langerhans cell hyperplasia), and furthermore the cells lack the dendritic morphology which is usually more typical of reactive Langerhans cells. But I have certainly seen inflammatory dermatoses and neoplasms with very prominent Langerhans cell hyperplasia, and that should certainly be considered. With this in mind in can be helpful to request Cyclin-D1, or as in this case IHC for BRAFV600E which is clearly positive in this case providing evidence of a clonal expansion. In some situations this can also highlight a potential therapeutic target with BRAF inhibitors, but unfortunately this patient's other haematological issues were already a significant factor, and the skin was a minor issue. 

I can see that Richard had spotted the accompanying eosinophils, and it is worth remembering that these can be present in LCH.

As Meenakshi and Vincenzo point out, there is not infrequent co-existence of LCH and myeloproliferative disease when LCH presents in adults (and have already provided references!) Perhaps this reflects a common progenitor cell of origin. In this case a subpopulation of cells did express myeloperoxidase. Given the transformation state, this could certainly indicate some spill over of neoplastic myeloid cells within the skin, but even so, the Langherans cell population is the dominant and also correlates well with the seborrhoeic dermatitis/intertrigo-like cutaneous presentation.

I did also request CD123, but the staining was minimal in this case. No fungi seen on PAS.

BW, Saleem

Very instructive Saleem, thank you.

I usually learn something making a misdiagnosis, however this time learned a lot having come very close to the correct diagnosis, and all this thanks to to you, Saleem and thanks to DermpatPro. 

Thanks for this lovely feedback. It reassures me that it is worthwhile posting these cases on DermpathPro.

very educative case