BACKGROUND: 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.
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.
CONCLUSIONS: 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.

BACKGROUND: Hidradenoma papilliferum (HP) is an adenomatous proliferation of mammary-like glands. These glands are located preferentially on the vaginal labia, the perineum and the anal skin. About ninety percent of HP occur on the vulva, with anal localization being much less common.
OBJECTIVE: To analyze the clinical and histological characteristics of anal HP and compare them to those seen on the vulva based on the literature.
METHODS: A monocentric retrospective analysis (in the medical and surgical proctology department of the Saint-Joseph Hospital Group, Paris) of patients for whom a diagnosis of anal HP was made based on pathological analysis of a resected sample.
RESULTS: A total of 14 female patients were included between 2012 and 2018. The mean age was 48.2 years (22-70). The tumor, single in all cases, was asymptomatic with very slow progression. It was located on the anal skin in all patients. It generally consisted of a round nodule measuring under 1cm that was barely prominent, translucent, depressible and mobile. In 15% of patients the tumor was ulcerated. Histologically, the tumor displayed the usual characteristics of HP. Only one relapse was seen, six years after resection.
CONCLUSIONS: The clinical and histological aspects of anal HP are the same as those of the vulva, which are better documented, namely a small, rounded, pink, translucent or bluish, and mobile tumor, with a smooth surface, and more rarely ulceration or budding, and in most cases asymptomatic. All HP were diagnosed in women and were located at the anal margin. Histopathological examination of an excised sample confirms the diagnosis and rules out a malignant tumor. The frequency of anal HP may be underestimated.

Trichoblastic carcinoma is a rare epithelial malignant epithelial tumor, its diagnosis is difficult and the therapeutic management is non-consensual. This retrospective study, carried out between 2009 and 2015, covered 21 cases and analyzed the diagnostic and therapeutic characteristics of trichoblastic carcinomas. Sex ratio is 2. Trichoblastic carcinoma predominated in the face (65% of cases), particularly in perinasal (30% of cases). Its clinical presentation is in 95% of cases as basal cell carcinoma, which is the first clinical diagnosis evoked. The average size of the tumors was 2.3cm in diameter (from 0.7cm to 15cm). The treatment of these tumors is surgical: the margins retained were on average 0.7cm (0.5cm to 1cm). The first excision was mostly performed under local anesthesia, healthy borders were found in less than 40% of cases, requiring another intervention under general anesthesia with reconstruction by flap or skin graft in nearly 80% of cases. The lymph node metastasis rate was 5%. Three cases of recurrence (17%) occurred between 18 months and 6 years follow-up, despite complete resection. One case recurred three times. These results highlight the difficulty of diagnosing trichoblastic carcinomas, often confused with basal cell carcinomas. Though larger, poorly limited and infiltrating, trichoblastic carcinomas are not really distinguished from basal cell carcinomas. Only the anatomopathological examination of the excision piece make it possible to conclude, the biopsy being most often insufficient. Their local aggressiveness requires a greater margin of excision. The micrographic analysis of Mohs, for the periorificial lesions of the face, would reduce margins, increase their reliability and limit the number of surgical revisions. Finally, the literature reports a high rate of ganglion and visceral metastases (between 9.5 and 11%). Initial search for distal lymph node or metastatic involvement is essential, as well as regular clinical follow-up.

Tubulo-papillary apocrine adenoma (TAA) is a very rare sweat gland tumor. TAA in association with syringocystadenoma papilliferum (SCP) is exceptional. A 2-year-old Tunisian child developed a mixed tumor on the scalp: TAA in association with SCP. Histologically, the tumor consisted of dilated duct-like areas with some apocrine gland-like areas. The superficial part of the tumor was connected to the epidermis and showed the characteristics of SCP. The characteristics and differences in histopathologic and immunohistochemical findings in this mixed tumor are described.

BACKGROUND: Syringomas are benign tumours of the sweat glands, the most familiar clinical presentation of which is the presence of multiple lesions on the eyelids. The aim of our study was to determine the clinical and histological characteristics of a large series of patients and to examine anatomoclinical correlations.
METHODS: This was a retrospective study conducted in all of the cases of syringoma analysed at the cutaneous histopathology laboratory in Strasbourg between 1970 and 2008. The clinical elements, patient history and diagnostic data were collated. All slides were re-read in order to determine the microscopic characteristics of the lesions.
RESULTS: Two hundred and forty-four lesions were included. The sex ratio was 0.27 and the mean age was 42 years (8 to 85 years). Multiple syringomas were noted in 76% of cases, of which 29.2% were eruptive, and one case occurred in a setting of metastatic melanoma. The sites of predilection were the face (56.7%, of which 36.3% on the eyelids), the chest (18.1%) and the neck (17.5%) for the multiple forms. The lesions were in the form of papules (67%), either brown (34.2%) or flesh-coloured (19.8%). Pruritus was reported in 14 cases, including 4 at vulvar sites (out of a total of 8). A diagnosis of syringoma was made by the clinician in only 30.2% of the multiple forms, with mastocytosis being proposed in 7.1% of cases. The clear-cell forms (18 cases) presented no special clinical features.
CONCLUSIONS: Syringomas are frequently multiple and are seen mainly in women. They are found predominantly on the face and trunk, and lesions are generally brown and pruritic, a little-known feature that accounts for the degree of diagnostic confusion with mastocytosis. The vulvar forms, which are often pruritic, are poorly known. The eruptive forms may include a hormonal component.

OBJECTIVE: Actinomycosis is a rare little known granulomatous suppurative disease, more common in women, aided by the use of contraceptive purposes intrauterine device (IUD). Pelvic location is the rarest with an extension to adjacent organs making preoperative diagnosis difficult and misleading clinical presentation. Early diagnosis of this affection determines the therapeutic strategy and avoids mutilating interventions especially in young women.
METHODS: We reviewed the record of women who consulted the department of obstetrics and gynecology at Ben Arous hospital (Tunisia) between January 2003 and December 2013 for a pelvic pain syndrome and in whom diagnosis of actinomycosis was suspected by clinical and imaging and confirmed by pathology.
RESULTS: Eight cases of gynecologic abdominopelvic actinomycosis were diagnosed during the study period. Seven patients were carriers of an intrauterine device, with an average duration of 5 years wearing. Functional signs were essentially pelvic pain and fever. Physical examination of patients mainly showed two clinical presentations: a pelvic tumor syndrome or abdominopelvic and an array of pelvic abscess or pelvic inflammatory disease. Radiological investigations were allowed to suspect the diagnosis of actinomycosis only in one patient, in whom percutaneous biopsy confirmed the histological diagnosis without resorting to a surgical procedure. Operative procedures performed were varied as appropriate. The diagnosis of actinomycosis was made by pathology without any cases of bacterial isolation. All patients received antibiotic treatment with penicillin. The subsequent evolution was favorable.
CONCLUSIONS: The diagnosis of actinomycosis should be considered in any invasive abdominal mass of neoplastic appearance and in case of table of genital infection especially in patients bearing IUD for 5 years or more.

BACKGROUND: Eccrine porocarcinoma is a rare cutaneous tumor arising from the intra-epidermal portion of eccrine sweat glands, the acrosyringium. Histoprognostic studies in large series are rare. Herein, we report a retrospective study of 50 cases.
METHODS: Fifty cases of porocarcinoma were retrieved from a histopathological register. Each histopathological sample was evaluated for the following criteria: presence or absence of dermal invasion, pattern of the infiltrative component (pushing or infiltrative), tumor thickness, lymphovascular emboli, perineural invasion and mitotic index. Clinical data and outcome were also retrieved for each patient.
RESULTS: Mean patient age was 77 years (range: 43-99 years). The mean duration of progression prior to diagnosis was 4 years and 5 months. The 2 most common skin locations were the head (38%) and lower limbs (20%). The lesions showed no specific distinctive clinical features. Six cases were in situ, and 44 were invasive (23 with limited infiltration and 20 with scattered infiltration). Mean tumor thickness was 4.37 mm (range: 0.5 to 20 mm). Neighboring or remote epidermal involvement was noted in 7 cases. Lymphovascular emboli were observed in 3 cases. No cases of neurotropism were observed. The average mitotic index was 6.5 mitoses/high power (×400) field. A mean follow-up of 24.3 months was available for 48 patients. Local recurrence was noted in 5 patients, 4 of whom died from visceral metastases. These 5 cases showed no distinctive clinical features, a scattered pattern of the invasive component, cuticular cells, significant tumor thickness (mean 12.8 mm, range 9-20 mm), and an elevated mitotic index. Two histopathological criteria were significantly associated with a metastatic outcome: scattered pattern of the dermal invasive component (P=0.04) and significant tumor thickness, above 10mm (P<0.01).
CONCLUSIONS: Porocarcinoma is a tumor without any particular clinical criteria to distinguish it from squamous cell carcinoma. The architecture of the invasive component and tumor thickness constitute 2 important histoprognostic criteria.