Post-traumatic ulcerated and chronic necrobiosis lipoidica of the elbow: A new entity?

BACKGROUND: Necrobiosis lipoidica (NL) is a chronic granulomatous dermatosis usually affecting the lower limbs, although less common sites have been described. Herein we report a series of cases of NL located on the elbow, with an unusual presentation and occurring after trauma or surgery. OBSERVATIONS: Our series includes three men and one woman, with a mean age of 64 years. Three had undergone surgery for elbow bursitis and one had had trauma after a fall from a horse, with exposure of subcutaneous tissue prior to healing. Within 5 years, they had all developed an atrophic erythematous annular plaque with papular and telangiectatic edges, with recurrent episodes of ulceration and scarring. Repeated tests for infectious agents were negative. Histological examinations showed granulomas and necrobiosis with palisading or early-stage palisading. Partial healing was achieved in two patients after 6 months of doxycycline. Treatment with adalimumab resulted in disappearance of the ulcers at 6 months in one patient. DISCUSSION: Unusual sites of NL impose consideration of other types of palisading granuloma or mycobacterial infections, which we were able to rule out. Two other cases of NL of the elbow similar to ours are reported in the literature. These cases, involving multiple ulcerations over a very long period of time, probably constitute a distinct entity because of the very distinct character of these 6 cases. Tetracyclines are partially active and tumour necrosis factor alpha (TNF)-alpha inhibitors may offer an option.

Clinicopathologic analysis of trichoblastoma and comparison with nodular basal cell carcinoma.

BACKGROUND: Trichoblastoma (TB) is an uncommon benign follicular tumour for which clinical data is limited since most reports originate from pathology studies. OBJECTIVE: To describe the clinical aspects of TB. METHODS: This is an ancillary study of a prospective multicentre cohort of 2710 clinically suspected basal cell carcinoma (BCC), including 935 nodular BCCs. Sixty-two cases were TB: they were analysed and compared to 935 nodular BCCs. RESULTS: TB mostly occurred in females (61% vs. 43% for BCC, P<0.01) of mean age 63 years. They were located on the head and neck, mainly on the nose and forehead, in 87% of cases. The mean size was 8.1mm, 77% were<10mm (55% of BCCs, P<0.001), 8% were ulcerated (vs. 21% of BCCs, P<0.02), and 47% persisted for more than 1 year (34% of BCCs, P<0.05). Most cases had a clinical presentation similar to nodular BCC, except for 5 small, flat, white papules and 1 anfractuous plaque. LIMITATIONS: Cases originated from a series of tumours clinically suspected as BCCs. DISCUSSION: Some 2.6% of tumours clinically diagnosed as BCC are in fact TB. TB occurs on the head, are more frequent in women, and are smaller and of longer duration than BCC. In most cases, clinical diagnosis on clinical grounds is difficult.

Androgen receptor expression in epidermal and adnexal tumours.

INTRODUCTION: Androgen receptor (AR) immunohistochemistry is used in general pathology and in dermatopathology, particularly for sebaceous tumours. The goal of this study was to quantify AR expression in benign and malignant epidermal tumours and adnexal tumours. METHODS: We studied AR expression in 301 skin lesions using standard immunohistochemistry and compared 10 trichoblastomas, 10 sebaceomas and 10 hidradenomas using 5 markers (cytokeratin 7 and 8, PHLDA1, BerEp4 and AR). RESULTS: The rates of AR expression were: 22% in basal cell carcinomas, 3% in squamous cell carcinomas, 92% in sebaceous tumours, 10% in follicular tumours and 22% in sweat gland tumours. Benign sebaceous tumours were AR+ in 97% of cases. Only 12% of sebaceous carcinomas showed no AR staining. The immunohistochemical profiles of the comparative study were as follows: sebaceoma: AR+, CK7-, CK8-, PHLDA1-, BerEp4-; hidradenoma: AR-, CK7+, CK8+, PHLDA1+, BerEp4+; trichoblastoma: AR-, CK7-, CK8-, PHLDA1+, BerEp4+. DISCUSSION: AR staining was positive in 92% of sebaceous tumours, including sebaceomas, in some cases indicative of Muir-Torre syndrome. AR staining is therefore highly sensitive for the diagnosis of sebaceous tumours, but it is non-specific and is best used in combination with other antibodies, notably anti-CK8 and PHLDA1, particularly to distinguish sebaceoma from hidradenoma or trichoblastoma.

[A case of cutaneous tuberculosis evolving for 50 years]. / Un cas de tuberculose cutanée évoluant depuis plus de 50 ans.

INTRODUCTION: Tuberculosis is an infection caused by Mycobacterium (M.) tuberculosis. It is rare in France. Clinical presentations vary, making demonstration of the cause of M. Tuberculosis difficult and rendering diagnosis and management difficult. PATIENTS AND METHODS: A 58-year-old man, born in Morocco, consulted for ulceration of the right forefoot that had been present since the age of 3 years. He had previously consulted at several dermatology departments. He had undergone numerous skin biopsies and bacteriological and mycobacteriological cultures but these did not contribute to the diagnosis. Slow extension and oozing were observed over time and resulted in functional disability. Given the evocative clinical aspect and despite further negative screening for mycobacteria, anti-TB quadrotherapy was prescribed and resulted in complete cure of the lesion. DISCUSSION: This case underscores the difficulty of diagnosing cutaneous tuberculosis. Such a diagnosis must be clinically suspected in the presence of long lasting destructive or verrucous skin lesions that fail to heal, even where cultures are negative, and anti-TB therapy should be putatively prescribed.

[Anatomoclinical and dermatoscopic study of trichoadenoma]. / Trichoadénome : description anatomoclinique et dermatoscopique.

INTRODUCTION: Trichoadenoma is a very rare follicular tumour with a remarkable histopathological appearance. In this article we present a series of 12 cases of trichoadenoma, as well as the anatomoclinical and dermatoscopic findings in a typical case. We discuss these findings in the light of an extensive literature research. PATIENTS AND METHODS: We collated 12 cases of trichoadenoma of indisputable diagnosis made at the dermatopathology laboratory of the Dermatological Clinic of the University Hospitals of Strasbourg over a 30-year period (1989-2018). RESULTS: The 12 cases comprised 7 women and 5 men, of average age 58.9 years, the majority having lesions on the cephalic extremity followed by the buttocks and thighs. Histopathological examination, which was similar in all 12 cases, showed multiple epidermal cysts containing an eosinophil lamellar keratin with a stratified wall without any visible hair, located in the superficial and mid dermis and appearing to be stacked on top of one another. In immunohistochemistry, broad spectrum keratin markers were still positive, the follicular marker Ber-EP4 weakly expressed and PHLDA1 was negative. For the case examined using polarized-light dermatoscopy, small rounded white-yellow areas were observed corresponding to cystic structures surrounded by irregular linear vessels. DISCUSSION: Trichoadenoma is a rare tumour seen in middle-aged adults of mean age 45 years, and has no sexual predominance. It is asymptomatic, slow-growing, variable in colour, measures less than one centimeter and is most often located on the face or buttocks. In terms of histology, the juxtaposition of multiple small cystic structures suggests a follicular origin. Differential diagnosis is made with trichoblastomas, which always intensely express PHLDA1 and/or Ber-EP4, desmoplastic trichoepithelioma, which consists of multiple much thinner spans in a highly fibrous stroma with clearly visible arborescent vessels over a white-yellow ivory background at dermatoscopy, microcystic carcinoma, which has a deeper extension, and plaque milium, in which the cysts are larger.

Clinicopathological study of 47 cases of sebaceoma.

BACKGROUND: Sebaceoma is a rare and poorly understood form of sebaceous tumour, and it is of great significance since it may reveal Muir-Torre syndrome (MTS). Herein, we present a series of cases with details of the histopathological appearance. PATIENTS AND METHODS: We examined records of cases labelled as sebaceous tumour recorded at the Strasbourg Dermatopathology Laboratory between 1991 and 2015. We include cases of benign sebaceous tumour predominantly involving immature basophilic cells. The clinical and histological data were collected as well as screening for a history of MTS. RESULTS: We studied 47 cases of sebaceomas (26 men), in patients of mean age 67.6years, located primarily in the head or neck (32 cases). Of the 17 patients followed up, 6 had MTS. Different types of architecture were seen: dermal nodule (9 cases) or cystic nodule (9 cases), multiple dermal nodules (22 cases), exophytic tumour (4 cases) and an appearance intermediate with sebaceous adenoma (3 cases). The cells involved were basophilic, with the presence of round ducts exhibiting an eosinophilic cuticle and, in rare cases, mature sebocytes. Mitoses were observed: mean 6.6/10 fields (0 to 19). In all cases, there was expression of CK17, EMA and androgen receptors, but not of BerEP4. DISCUSSION: Sebaceoma is a small benign tumour but identification is imperative due to association with MTS. A knowledge of the associated cytological and architectural elements - particularly cysts and labyrinthine patterns - and immunolabelling enable differential diagnosis with respect to other tumours. The extra-facial and cystic forms in particular require screening for MTS. If there is any doubt, immunolabelling of androgen receptors provides a precious tool.

[Muir-Torre syndrome associated with Waldenstrom's macroglobulinemia]. / Syndrome de Muir-Torre chez un patient atteint de maladie de Waldenström.

BACKGROUND: Muir-Torre syndrome (MTS), a cutaneous variant of Lynch syndrome, consists of hereditary predisposition to cutaneous tumours and gastrointestinal and gynaecological neoplasms, with autosomal dominant transmission. It is associated with mutations in genes coding for proteins in the DNA mismatch repair system. PATIENTS AND METHODS: Herein, we report a case of a male patient presenting Waldenstrom's macroglobulinemia since the age of 50 and which, after the age of 65 years, developed into sebaceous tumours (5 sebaceous adenomas, 1 sebaceoma, 1 sebaceous carcinoma) and colonic lesions (4 adenomas). The clinical phenotype was consistent with MTS. Somatic analysis carried out on one sebaceous tumour showed instability of the microsatellites with loss of expression of MSH2 and MSH6 although constitutional genetic analysis showed no germline mutations known to be harmful. DISCUSSION: This noteworthy case raises a number of questions, including the possibility of association between STM and Waldenstrom's macroglobulinemia, which is discussed herein.