Tumor of follicular infundibulum - reappraisal in a series of 28 patients with critical review of the literature.

BACKGROUND AND OBJECTIVES: Tumor of follicular infundibulum (TFI) has been described as a neoplasm - isolated and multiple - and in association with other lesions. Its histopathologic definition is controversial. PATIENTS AND METHODS: We present a histopathologically analyzed series of 28 patients with TFI features. This has been supplemented by a search in MEDLINE on the literature on this subject. The corresponding figures given in these articles have been discussed and analyzed. RESULTS: Patients comprised 16 women and twelve men. TFI features were seen in five patients with nevus sebaceous, two trichofolliculomas, one dilated pore Winer, eight viral warts, one dermatofibroma, six seborrheic keratoses, three actinic keratoses, one invasive squamous cell carcinoma, and one basal cell carcinoma in association with a squamous cell carcinoma/actinic keratosis. After study of the literature especially of solitary cases of TFI, we interpret such cases mostly as variants of seborrheic keratoses with variable degree of infundibular, isthmic and/or sebaceous differentiation with or without regression. CONCLUSIONS: We regard TFI as an epithelial growth pattern which may occur in hamartomatous, inflammatory, infectious, reactive, or neoplastic conditions, in most solitary forms likely best classified within the histopathological spectrum of seborrheic keratoses.

Erythema Nodosum, Early Stage-A Subcutaneous Variant of Leukocytoclastic Vasculitis? Clinicopathological Correlation in a Series of 13 Patients.

Erythema nodosum (EN) is considered to represent a septal panniculitis. In a period from January 2000 until June 2018, we clinically and histopathologically investigated 124 patients with EN, 13 (10.5%) of them in an early stage demonstrating features of a leukocytoclastic vasculitis (LCV) around postcapillary venules of the subcutaneous fat. Three of these patients presented with EN on the lower legs and Sweet syndrome on the head/neck, arms, or trunk. 19.3% and 70.2% of patients demonstrated "classic" features of subacute and chronic forms of EN, respectively. Histopathologically, in cases of early EN apart from septally accentuated vascular damage and neutrophils with nuclear dust, eosinophils were evident in 5 specimens as well, in one case even with flame figures as seen in Wells syndrome. The inflammation spilled over to the dermis and lobular panniculus in 12 and 10 specimens, respectively. From the same time period and for comparison, we investigated 497 cases of "classic" LCV. Depending on the degree of vascular damage and the presence of neutrophils and nuclear dust, 65.8% presented with acute, 18.9% with subacute, and 15.3% with late-stage disease. In the latter, only a few neutrophils but rather lymphocytes and macrophages were present. Four hundred forty patients revealed an involvement of the deep dermis; of those, in 342, a septal inflammation was present as well, whereas in 94, the process was purely dermal. The subcutis was missing for evaluation in 61 cases. These results indicate a closer relationship between EN and LCV than previously considered.

Erosive pustulöse Dermatose der Kopfhaut: Neubewertung einer zu wenig beachteten Entität.

Die erosive pustulöse Dermatose der Kopfhaut (EPDK) ist eine entzündliche Erkrankung unbekannter Ätiologie. Wir besprechen die EPDK und präsentieren unsere eigene klinische und histopathologische Erfahrung von elf Patienten. Die EPDK neigt dazu, spontan die kahle Kopfhaut älterer Patienten zu befallen. Anamnestisch wird häufig - so auch bei vier unserer Patienten - eine vorausgegangene Operation an selbiger Stelle angegeben. Koronare Herzerkrankung, cerebraler Insult, arterieller Hypertonus, Diabetes mellitus und ernste Krebserkrankungen wurden ebenfalls häufig als Komorbidität diagnostiziert. Die meisten Patienten zeigen trotz antiinflammatorischer Lokaltherapie einen schwankenden klinischen Verlauf, bei einigen heilt die Läsion unter Narbenbildung ab. Histopathologisch findet sich eine Kruste oder Erosion mit Granulationsgewebe-ähnlichen Veränderungen im Korium mit späterer Entstehung einer Narbe. Neben einer lokalen und aktinischen Schädigung könnten eine eingeschränkte Immunität und Mikrozirkulation prädisponierende Faktoren der Erkrankung sein. Analog zum Pyoderma gangraenosum muss die EPDK bei nichtheilenden Wunden älterer Patienten bedacht werden, nachdem die Differenzialdiagnosen, die diese Erkrankung simulieren, ausgeschlossen wurden. Da vorausgegangene oder benachbarte Basalzell- und insbesondere Plattenepithelkarzinome häufig sind und infiltrative Varianten jenseits des klinisch sichtbaren Krankheitsprozesses vorkommen, kann im Zweifelsfall eine sogenannte histologische Kartierung der umgebenden Haut ratsam sein.

Erosive pustular dermatosis of the scalp: reappraisal of an underrecognized entity.

Erosive pustular dermatosis of the scalp (EPDS) is an inflammatory dermatosis of unknown etiology. Herein, we present a review of the disease and report our own clinical and histopathological experience in eleven patients. EPDS tends to spontaneously affect bald areas of the scalp in elderly individuals. A history of previous surgery at the same site - as observed in four of our patients - is common. Coronary artery disease, cerebrovascular insult, arterial hypertension, diabetes mellitus, and severe cases of cancer were frequent comorbidities. Most patients show an undulating clinical course despite topical anti-inflammatory treatment; in some individuals, the lesions heal with scarring. Histopathology reveals scaly crusts or erosions and granulation tissue-like changes in the dermis, evolving into a scar in more advanced stages. Apart from actinic/local damage, impaired immunity and microcirculation may be predisposing factors of the disease. Similar to pyoderma gangrenosum, EPDS must be considered in the context of nonhealing wounds in the elderly after the differential diagnoses mimicking EPDS have been ruled out. Given that previous or concomitant adjacent basal cell or squamous cell carcinoma is a common finding and that infiltrative variants extending beyond the clinically visible tumor may occur, histological mapping of the surrounding skin may be advisable in doubtful cases.

Annular Lichenoid Dermatitis (of Youth) Immunohistochemical and Serological Evidence for Another Clinical Presentation of Borrelia Infection in Patients of Western Austria.

Annular lichenoid dermatitis of youth (ALDY) is a more recently described inflammatory disease of the skin of unknown etiology with clinical similarities to morphea. The authors clinically, histopathologically, and immunohistochemically investigated 14 biopsies from 12 patients in western Austria with this disease. There were 6 female and 6 male patients with solitary (n = 7) and multiple lesions (n = 5) affecting the trunk (n = 11), upper arm (n = 2), thigh (n = 1), and calf (n = 1). Clinically, early lesions were erythematous in nature leading to central paleness, scaling, wrinkling, dermal atrophy, slight pigmentation, and telangiectasia later on. Histopathologically, all specimens showed the typical features of ALDY with a superficial lichenoid process with sprinkling of lymphocytes along the basal cell layer and within the epidermis accompanied by mild fibrosis. Pigment incontinence, superficial fibrosis, and dilatation of superficial capillary vessels are prominent features in more advanced stages of disease. Immunohistologically, using a polyclonal antibody against Borrelia, 11/14 specimens revealed spirochetes, either vital (n = 4) or degenerated (n = 7), in close proximity to collagen bundles. Thirteen of 14 specimens in addition showed focal (n = 4) or clustered (n = 9) positivity for CD20 in the papillary dermis. Nine of 12 sera tested for Borrelia with an enzyme-linked immunosorbent assay were positive. Lichen sclerosus et atrophicus and morphea have previously been reported to be possibly related to Borrelia infection. We postulate that a similar relationship to Borrelia infection may be true for ALDY implying that ALDY may be an early superficial stage of morphea.

Angiomatoid fibrous histiocytoma - case series with emphasis on a late fibrotic variant.

BACKGROUND: Angiomatoid fibrous histiocytoma (AFH) is a rare, low-grade malignant, subcutaneous neoplasm in children or young adults. METHODS: AFHs in different disease stages were studied histologically, in part, also immunohistologically, and by fluorescence in situ hybridization. RESULTS: Depending on the degree of fibrosclerosis, nine AFH were divided into the following categories: classic type (n = 3): well-defined subcutaneous lesions composed of multinodular spindle to epithelioid (histiocytoid) cells surrounding a pseudoangiomatous space filled with blood. Peripherally, there is a fibrous pseudocapsule and an inflammatory infiltrate. Early sclerotic type (n = 4): the fibrous capsule extends more to the inner circle of the lesion, focally replacing the cellular neoplastic component and pseudoangiomatous spaces. Late sclerotic type (n = 2): the architecture of AFH with its zonal arrangement of an outer fibrous and inner cellular component is largely replaced by fibrosis occluding the pseudovascular space in the center of the lesion. Immunohistochemistry was available in 5/9 cases with positivity for EMA (5/5), desmin (3/5), caldesmon (1/2), and CD99 (2/5). One of two cases tested displayed EWSR1 rearrangement. CONCLUSION: Late-stage AFH may present with marked fibrosis obscuring the real nature of the lesion and may easily be misinterpreted by the unwary as a harmless fibrotic condition.

Bioinductive Collagen Implant Augmentation for Myotendinous Achilles Rupture in a Teenage Competitive Gymnast: A Case Report.

CASE: A 16-year-old female competitive gymnast presented to our orthopaedic clinic with an acute Achilles tendon rupture at the myotendinous junction. Direct end-to-end repair was performed and augmented with a bioinductive collagen patch. The patient had increased tendon thickness at 6 months postoperatively, as well as significant improvements in strength and range of motion at 12 months. CONCLUSION: Bioinductive collagen patch augmentation of Achilles tendon repair may be a useful adjunct for myotendinous junction Achilles ruptures, particularly in high-demand patients including competitive gymnasts.

Vasculitides and occluding vasculopathies, challenges in recognizing histopathological patterns, and their solutions.

In this review, we propose a classification of vasculitides and occluding vasculopathies using the clinicopathological correlation as the basic process. We use an algorithmic approach with pattern analysis, which allows reliable reporting of microscopic findings. We first differentiate between small and medium vessel vasculitis. Second, we differentiate the subtypes of small- and medium-sized vessels. Finally, we differentiate vasculitides according to the predominant cell type into leukocytoclastic and/or granulomatous vasculitis. Regarding leukocytoclastic vasculitis as a central reaction pattern of cutaneous small/medium vessel vasculitides, its relation or variations may be arranged in a wheel-like order. With respect to occluding vasculopathies, the first two steps are identical to the algorithm of vasculitides, and we finally differentiate according to the time point of the coagulation/reorganization process and the involved inflammatory cells/stromal features. By visualizing the criteria in the style of bar codes, clinical and histological overlaps and differences may become more transparent.

Circumscribed palmar hypokeratosis: Successful treatment with fluorouracil cream.

INTRODUCTION: The pathogenesis of circumscribed palmar hypokeratosis (CPH) is still controversial, and to date there is no treatment of choice. METHODS: We report on a patient with CPH responding to treatment with fluorouracil cream. RESULTS: The clinical course and histopathological features in our observation point towards the possibility of an underlying squamous cell carcinoma in situ presenting as CPH. CONCLUSION: We suggest that fluorouracil cream treatment should be considered as a therapeutic option in cases of CPH.

The value of immunohistochemistry in atypical cutaneous fibrous histiocytoma.

Atypical cutaneous fibrous histiocytoma is a rare variant of dermatofibroma/fibrous histiocytoma characterized by striking atypia, thus resembling atypical fibroxanthoma. We studied 9 examples of ACFH histopathologically and immunohistochemically to investigate the nature of these atypical cells. Histology revealed ill-defined skin nodules, which were polypoid in 6 cases. A minority of mononuclear and giant cells (< 5%) revealed striking pleomorphism and showed large nuclei with prominent nucleoli. Immunohistologically, the atypical cells expressed vimentin, but were negative for S-100 protein, the keratin marker MNF116, alpha smooth muscle actin, CD34, factor XIIIa, and monocyte/macrophage markers Ki-M1p, KP1 (CD68), and MAC387. Positivity for MiB1 was very modest (< 1%) and limited to small- and medium-sized, inconspicuous cells. Multinucleate giant cells proved to be heterogenous, on one hand cells with differentiation toward macrophages with positivity for Ki-M1p and KP1, on the other toward fibroblasts positive for vimentin only. These immuno-histochemical results for differentiation markers in atypical cutaneous fibrous histiocytoma are similar to our previous findings and data in atypical fibroxanthoma; MiB1 helps to separate these entities from each other as the latter shows a very high proportion of proliferative atypical cells corresponding to the numerous mitoses seen in routine sections.