CASO CLÍNICO REVISTA PORTUGUESA DE CIÊNCIAS VETERINÁRIAS Metastatic malignant pilomatricoma with bone and lung metastasis in a Portuguese Water Dog Pilomatricoma maligno metastizante com metastização óssea e pulmonar num Cão de Água Português Rute M. Noi"a#$% &abíola ( Costa)% Rafael Pratas+% Maria C. Peleteiro# 1Interdisciplinary Centre of Research in Animal Health (CIISA), Faculty of Veterinary Medicine, echnical !ni"ersity of Lisbon, 13&&'(77 #isboa, *ortugal ,Uni"ersidade Federal Fluminense, Rua Vital Brasil, 64, Santa Rosa, Niterói, Rio de Janeiro – RJ ,(%,&'%(& – Brasil %Centro de Cirurgia Veterinária de Loures, Rua José Manuel Cerqueira Afonso dos Santos, 35B 2685-402 Prior Velho, *ortugal Summary: Pilomatricomas consist of neoplastic proliferations the hair follicle in three distincti"e areas (infundibu- of germinati"e cells of the follicular matrix or hair bulb9 lum, isthmus and hair bulb) facilitates characterization Malignant pilomatricomas are considered rare, with only a of the "arious tumor types, in :hich mali+nant $eha"ior small number of cases reported in dogs. Here :e present a case of malignant pilomatricoma in a *ortuguese ;ater Do+ with a is seldom reported. 3-year clinical history of recurrent pilomatricomas with e"i- A pilomatricoma (pilomatri8oma or calcifyin+ dence of cellular atypia from the first diagnosis. The malignant epithelioma of Malherbe) consists of a neoplastic pro- behavior of the tumour in this animal included bone and lung liferation of +erminati"e cells of the follicular matrix, metastasis. The bone in"asion in the C1 "ertebra resulted in or hair bulb (Gross et al., 2005; Lopansri and Mihm, se"ere pain and discomfort that finally led to euthanasia after a se"ere crisis of respiratory distress9 1980). Pilomatricomas occur most commonly in rela- ti"ely young animals on the proximal legs and dorsal /eywords: malignant pilomatricoma, *ortuguese ;ater Dog, trunk, particularly o"er the rump and shoulders, and bone and lung metastasis usually present as solitary, :ell circumscribed, firm to hard dermal andJor su$cutaneous masses (Fold' Resumo. *ilomatricomas s=o neoplasias com ori+em nas et al c4lulas +erminati"as da matri> dos fol?culos pilosos9 @s schmidt and Shofer, 1992; Neto ., ,009). Some pilomatricomas malignos são considerados neoplasias raras, tumors ha"e a +ritty or bony consistency and lesions com apenas um redu>ido nAmero de casos relatados em may be chalky :hen sectioned (Goldschmidt and canídeos. No presente trabalho re+ista-se um caso de piloma' Shofer, 1992; Gross et al., 2005; Massone et al., tricoma em Cão de Bgua *ortuguês, que e"oluiu ao longo de % 2005). The o"erlying epidermis is often atrophic and anos, com recidi"as nas quais se registou sinais de atipia celular et al et al desde o primeiro diagnóstico. O comportamento maligno deste alopecic (Gross ., ,&&6H Massone ., 2005). tumor, que conduziu ao desfecho final, caracterizou-se por Histolo+ically, pilomatricomas are composed of metastização no tecido ósseo e pulmonar. A in"asão óssea na multiple cystic structures of "arying size, lined pre- vértebra C1 resultou em dor se"era e desconforto que le"aram E dominantly $y small, basaloid Ieratinocytes :hich decisão de eutanásia, após uma +ra"e crise de insuficiência resemble the matrix cells of the anagenic hair bulb9 respiratória. Mitotic activity is fairly high but nuclear or mitotic Palavras-cha"e: pilomatricoma maligno, Cão de Água *ortu- atypia is not present (Goldschmidt and Shofer, 1992; guês, metástases ósseas e pulmonares Gross et al., 2005). The neoplastic cells undergo matrical-type Ieratinization characterized $y abrupt transition to large masses of Ieratinized K+host’ or Introduction ‘shado:L cells that fill the cysts’ lumen (Goldschmidt and Shofer, 1992; Gross et al., ,&&6; Neto et al., Follicular tumors are a relati"ely common e"ent in 2009). Ghost cells ha"e a nucleus that does not stain small animal dermatology, more frequently reported with Hematoxylin&Eosin appearing as acidophilic in dogs and rarely in cats (Goldschmidt and Shofer cells with an apparent central "oid. They often become 1992; Scott et al., ,001). Separating the structure of minerali>ed, and osseous metaplasia may occur, particularly in later stages, so that some tumors of chronic duration exhibit a predominance of ghost cells *Correspondência: rute.noi"[email protected] and bone with little residual epithelium (Gross et al., el: +351 3652838; Fax: +351 213652895 2005). 101 Noiva RM et al. RPCV (2012) 111 (581-582) 101-104 A sur"ey of follicular neoplasias diagnosed in the Laboratory of *athological Anatomy of the Faculty of Veterinary Medicine of the echnical Uni"ersity of Lisbon, between 2005 and 2010, identified 182 cases (Table 1). Pilomatricomas accounted for 31 of these tumors, with a single case of malignant behavior; the one reported here. Malignant pilomatricomas are considered rare, with only a small number of cases reported in dogs, some of :hich describing metastatization to the lymph nodes, lungs and bone (Maxie et al9 ,&&)). The aim of the present :ork is to add a new case to these rare reports of malignant pilomatricoma in dogs (Carroll et al., 2010; Jackson et al., 2009; Johnson et al., 1983; Rodriguez et al., 1995; Sells and Conroy, 1976), this Figure 1 - Dorsal pilomatricoma. he tumor exhibits se"eral lobules time in a *ortuguese $reed. separated $y moderate fibrous stroma. Abo"e and on the left, foci of abrupt Ieratinization, some of :hich calcified, can be seen. Clefts corresponding to cholesterol crystals are shown in the center of the image. The insert shows ghost cells in close contact :ith tumour cells Case Report with "acuolated nuclei showing moderate anysokariosis. A few mitosis can be seen (arrows) (H&E, 100x, insert x400) In August 2008, Black, a three-year-old *ortuguese ;ater <o+ under:ent sur+ery to remo"e a % cm dorsal nodule :hich :as then sent to the Laboratory of *athological Anatomy of the Faculty of Veterinary Medicine (#is$on) for analysis9 Histopatholo+y reported this nodule to be a pilomatricoma, a prolife- ration of basaloid cells forming lobules with cystic central abrupt matrical Ieratinization and numerous ghost cells. Although the mitotic index :as lo:, with less than one dividing cell per ten high po:er fields, there :as some evidence of cellular atypia. Se"eral lobules sho:ed foci of bone formation and necrosis with cholesterol crystal clefts (Figure 1). In some areas, ruptured cysts had triggered inflammation and desmoplasia. Eighteen months later, Black :as again submitted to Figure ) - Pilomatricoma o"er the left eye. The tumor is composed of undifferentiated cells similar to the atypical ones of the first tumor9 surgery to remo"e three small nodules. These ne: These cells can $e seen infiltrating the stromal interstitial tissue to:ards masses :ere located (i) in the head o"er the left eye the left. An area of abrupt matrical Ieratinization is patent abo"e on the (2 cm), (ii) in the left pectoral region (0.5 cm) and (iii) right (H&E, 100x) in the lumbar left area (1 cm). Upon histopathological analysis all three tumors sho:ed characteristics :ere frequent, accounting for a mean of two dividing already described for the tumor previously remo"ed, cells per high po:er field. No calcification or bone although with clearer signs of malignant behavior, formation :ere present in any of these nodules. especially in the facial and pectoral nodules, such as Si8 :eeIs after the last sur+ery, -lacI :as presented indistinct limits and dermal infiltration (Figure 2). The for orthopedic e"aluation due to se"ere right thoracic neoplastic cells had a less basaloid appearance, and limb lameness without e"idence of joint pathology :ere larger, with paler nucleus and distinct nucleoli. distally to the shoulder. Clinical examination re"ealed Single cell necrosis :as common and mitotic figures a se"ere cervical pain on manipulation of the neck. 2able 1 - Retrospecti"e sur"ey of the archi"es of the Laboratory of *athologic Anatomy of the Faculty of Veterinary Medicine (2005-2010). Follicular neoplasm type, species and sex distribution ype of Neoplasm Cats Dogs Other Animals Female Male Female Male Guinea Pi+ Ferbil Rabbit richoepithelioma % ( ,G %% & & richoblastoma . ) ,7 %G & & 1*+1± Pilomatricoma & & 17 11 1* 1* Malignant pilomatricoma & && 1 & & *Male; T Female 102 Noiva RM et al. RPCV (2012) 111 (581-582) 101-104 Radio+raphic studies :ere performed, showing bone proliferation o"er the left wing of C1 (Figure 3). In the following :eeks, BlackLs condition :orsened. The owners opted for euthanasia after a se"ere crisis of respiratory distress and pleural effusion. !pon necropsy, the only mass present in the sIin :as a nodule, 196 cm in diameter, located o"er the ri+ht eye9 he left :in+ of the atlas (C1) :as marIedly enlar+ed, its dimensions being 5.5 x 3.5 x 3 cm, slightly pro- jecting into the spinal canal and lightly compressing the spinal cord (Figure 4A). A negligible number of small $lood clots :ere present in the epidural space. The pleural cavity contained around 100 ml of hemor' rhagic fluid and $oth lungs exhibited "arious nodules, ranging from &96 to 4 cm in diameter (Figure 4B). Figure 3 - Radio+raphic image of the cervical area, "entrodorsal vie:9 Sectioning the nodules re"ealed a :hite, rough and Note how the left wing of the atlas (bottom side of the image) appears deformed $y a mottled, irre+ularly radiopaque mass pasty cut surface with the consistency of calcified tissue. The surrounding pulmonary parenchyma :as se"erely congesti"e. Various tissue samples :ere collected from the necropsy and fixed in 10% buffered formalin. They :ere submitted for routine histopathological proces- sing, except for the bone tissue, :hich :as previously submitted for 24h to a commercial decalcifying solu- tion (OSTEOMOLLV, MERCK).