6 Years’ Experience of Mohs Micrographic Surgery in a Portuguese Hospital

Introduction: Mohs micrographic surgery (MMS) is a surgical method of treating skin tumors that consists of histological control of the tumor margins using horizontal slices in thin, freshly frozen layers. This technique is a preferred indication for cutaneous facial tumors (basal and squamous cell carcinoma, among others) associated with higher risk of recurrence, recurrent tumors, tumors with undefined clinical margins, when there is perivascular and perineural involvement or with aggressive histological subtypes. Methods: The authors carried out a retrospective study of a 6-year period (from July 2012 until June 2018) at a Portuguese hospital – Egas Moniz hospital, to define the characteristics of patients undergoing Mohs micrographic surgery and to evaluate the advantages of this technique. The following factors were analyzed: age, gender, provenience, diagnosis, tumor location, number of stages of MMS, type of reconstruction of the surgical defect, follow-up and recurrences. Results: A total of 835 tumors were excised, 459 in male patients and 376 in female patients. The mean age at surgery was 71 years old (range 23- 95 years). Most of the lesions submitted to MMS were basal cell carcinomas (87%) and the most common location was the nasal pyramid (43%). In 44% of the cases, it was necessary to perform more than one micrographic stage. Half of the surgical defect closures were performed by graft or skin flap. Considering patients with a follow up equal or superior to 3 years, the recurrence rate was 4.9%. Discussion: The most frequent diagnosis was basal cell carcinoma, reflecting the importance of MMS in this type of skin malignancy, in both primary and persistent/recurrent lesions. Compared to other European surgery reviews, our recurrence rate is within normal range. This fact is particularly relevant, if we consider that our institution receives patients sent from hospitals and dermatologists from all over the country, specially selected for tumor aggressiveness or previous relapse. More than half of these patients were referred from other centers and consisted of persistent/recurrent basal cell carcinomas. The follow-up at recurrence for MMS was 27.9 months, supporting that a long follow-up of these patients is necessary. Conclusion: MMS allows lower rates of recurrence compared to simple surgical excision, so its practice should be encouraged in selected tumors. The surgical control of the margins instead of the “blind margins” is an advantage in saving healthy tissue and allows the complete excision of the tumor in the same surgical time.

Giant fibrous hamartoma of infancy: pitfall of CD34 positive dermal mesenchymal tumor

Fibrous hamartoma of infancy (FHI) is a rare benign soft tissue tumor with a triphasic organoid histologic appearance. The authors present a case of a 21-month-old healthy girl with a slowly growing flesh-colored subcutaneous plaque 12cm in size on the lower back, with overlying hypertrichosis. A punch biopsy revealed a proliferation of spindle cells infiltrating the dermis and hypodermis organized in a dense storiform pattern with a strong diffuse positivity for CD34. The diagnosis of congenital dermatofibrosarcoma protuberans (DFSP) was considered and an excision was performed. Histopathologic analysis showed an extensive poorly demarcated mass infiltrating the dermis and hypodermis, composed of different components: a monomorphous fibroblastic/myofibroblastic component, a mature adipose component, and an immature mesenchymal basophilic component. The clinical aspects with the histologic and immunohistochemical features led to the diagnosis of giant fibrous hamartoma of infancy. In our case the strong diffuse CD34 positivity was a diagnostic pitfall leading to an incorrect hypothesis of congenital DFSP. The characteristic triphasic histology of FHI was missed owing to the small size of the punch biopsy. This article highlights the importance of being aware of the CD34+ dermal mesenchymal tumor differential diagnosis and the necessity of appropriate size biopsies to avoid sampling error.

Cutaneous complication of perinatal hypoxia

Subcutaneous fat necrosis of the newborn is an uncommon, transient, and self-healing panniculitis, mostly affecting term newborns with perinatal complications. The authors present a case of a female full-term neonate, born from an uncomplicated pregnancy, admitted into the neonatology unit 5 hours after delivery because of refractory multifocal seizures in the context of hypoxic-ischemic encephalopathy. Nine days after birth, indurated and erythematous nodules and plaques were noted on the left arm and back. Skin biopsy was compatible with subcutaneous fat necrosis of the newborn. Laboratory evaluation including serum calcium showed normal values. No treatment was initiated. This entity generally follows an uncomplicated course. However, there are important complications for which the patient must be regularly monitored, including thrombocytopenia, hypoglycemia, hypertriglyceridemia, and most importantly, hypercalcemia. Patients should have serial serum calcium determinations for up to 6 months after the appearance of the skin lesions. The early diagnosis and prompt treatment of hypercalcemia are essential to prevent severe complications.

Dermatofibrosarcoma protuberans: a clinicopathological study of 20 cases

AIM

To review the dinical and histological data of 20 cases of dermatofibrosarcoma protuberans presenting at two dermatology centres in Lisbon from 1978 to 1998.

PATIENTS AND METHODS

The 20 subjects comprised nine males and 11 females ranging in age from 25 to 79 years, with highest frequency of subjects in the 30-50 year olds. We reviewed the clinical features, histopathological aspects, including morphologic variants and immunohistochemical studies.

RESULTS

Median age at diagnosis was 51 years and the trunk was the most frequent location. The characteristic histologic storiform pattern was seen in all cases. Three subjects presented fibrosarcomatous areas, one with myoid differentiation and another with multinucleated giant cells. Immunohistochemical stains revealed CD34 expression in the 18 specimens tested, FXIIIa was negative, and these two antigens proved important for the differential diagnosis of this neoplasm. Local wide excision was performed in 13 cases and seven patients underwent Moh's micrographic surgery. Follow-up ranged from 2 months to 17 years and three recurrences were recorded, two following classical surgery and one after Moh's surgery; there was no difference in the rate of local recurrence (15%) for the two kinds of treatment in our series.