A consultation case. Not my field, but I suppose both patient and dermatologist are desperate.  
Female patient, born in 1970.  
2013, 2014 and 2015: small skin nodules on chin and nasolabial fold, removed by laser. Biopsy (as remembered by patient, material and report lost) had shown "lymphocytic infiltration" or "lymphocytic inflammation". Pancreas dysfunction from childhood, thyreoectomy in 2003, currently climacteric.  
01.04.16 - rapid onset of prominent painless edema of the chin region. Antihistamine, antibiotics and local treatment without effect. 05.16 - Dexasone i/v with edema regression, immediate relapse one day after treatment. Peroral Prednisone 30mg/d commenced with good effect for 2 months, relapse at decreasing dosage to 15mg/d.  
17.07.16 - visit to a new dermatologist. Several hard subcutaneous nodules of various sizes and deepness, papular and papular-pustular elements, teleangioectasies; recurrent hard edema (mostly in the morning). Dermatoscopy - dilated capillaries, hyperplastic sebaceous glands. Dg: granulomatous rosacea with gnatophyma? chronic angioedema? granulomatous diseases (lupus, sarcoidosis, TBC, lepra)? Prednosone further decreased to 7.5mg/d, Metronidazole and local therapy added. The condition worsened, deep subcutaneous infiltrates expanded. Dermatoscopy showed apple jelly-like changes in some papules.  
29.07 Punch biopsy performed (see photos marked 1-…). Visible massive lymphoid infiltration expanding into deep derma, predominantly rather monotonous T-cell. Lymphocytoma reported. Unfortunately, there is no block for additional stains.  
Prednisone 2.5mg/d. Treatment with Metronidazole and local treatment - negative dynamics.  
29.08 - IgM to B. burgdorferi found. Doxocyclin for 20 days administered without positive effect: clinical worsening, increased edema, new dermal and hypodermal nodules, general condition intact. IgМ to B. burgdorferi persist, normal IgG titre.  
07.11 Repeated biopsy from a deeper infiltrate (photos marked 2-…). Pseudolymphomatous folliculitis reported. Retrospective immunohistochemistry showed CD4+ infiltrate. TCR rearrangement is not available here.  
Working diagnosis - rosacea with persistent solid edema (the attached photos of the patient taken at that moment, scars are from previous biopsies). Isotretinoin 20mg/d commenced, moderate positive dynamics. In 1.5 months - gradual local worsening with erosions, submandibular lymphadenopathy and subfebrile fever appeared for the first time. No effect from antibiotics, bacteriology negative, fungi negative.  
31.01.2017 - third biopsy (3 - …). Isotrenoin discontinued, local changes persist. Lymph node biopsy planned.  
 
Well, I am not a particular specialist in skin pathology, lymphomas included, and rely on your assistance. Could it be an exotic lymphoproliferation, after all?  
 
Next biopsy, both skin and regional node, marked 4s... and 4n.... The skin infiltrate looks very much like biopsy Nr 2 (a lot of necrosis this time, though). Lymph node is mostly reactive, but there are a lot of intrasinusoidal CD4+ T-cells.