|Year : 2014 | Volume
| Issue : 4 | Page : 175-176
Seemingly insignificant, but crucial cytomorphological leads in diagnosis of pilomatricoma of parotid region
Chakshu Bansal, Jyoti Mishra
Department of Pathology, School of Medical Sciences and Research, Sharda Hospital, Greater Noida, Uttar Pradesh, India
|Date of Web Publication||14-Oct-2014|
Department of Pathology, School of Medical Sciences and Research, Sharda Hospital, Greater Noida, Uttar Pradesh - 201 306
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Pilomatricoma is a benign cutaneous appendegeal neoplasm which occurs as dermal nodule on head and neck region of children and young adults. Tumors pose a potential difficulty when diagnosed on fine-needle aspiration cytology. In this communication, we illustrate the cytomorphological features of pilomatricoma in a 38-year-female who presented with a nodule over the parotid region. Repeated aspirations of this nodule revealed low cellularity and cytology was hence inconclusive. The final diagnosis was made on histological examination and then retrospectively when those paucicellular cytological smears were analyzed again; showed features that could have driven the pathologist toward pilomatricoma. Familiarization and careful cytological examination under appropriate clinical conditions is warranted.
Keywords: Fine needle aspirate, paucicellular, pilomaticoma
|How to cite this article:|
Bansal C, Mishra J. Seemingly insignificant, but crucial cytomorphological leads in diagnosis of pilomatricoma of parotid region. Int J Trichol 2014;6:175-6
|How to cite this URL:|
Bansal C, Mishra J. Seemingly insignificant, but crucial cytomorphological leads in diagnosis of pilomatricoma of parotid region. Int J Trichol [serial online] 2014 [cited 2022 Jun 28];6:175-6. Available from: https://www.ijtrichology.com/text.asp?2014/6/4/175/142866
| Introduction|| |
Pilomatricoma, also called calcifying epithelioma of Malherbe, is a benign skin adnexal tumour of hair matrix origin. The lesions are typically found in head and neck of young adults and children. [1,2] Histopathological features of this lesion are characteristic and well recognized, but diagnosis is difficult on cytology and usually misdiagnosed as an epidermal inclusion cyst, squamous cell carcinoma, or metastatic neoplasm. ,,,,, Low cellularity of cytological smears can further escalate the difficulty in diagnosis.
We present a case of pilomatricoma of parotid region diagnosed after histopathological examination when no conclusive diagnosis was made on cytology due to paucicellularity.
| Case report|| |
The 38-year-old female presented with 1-month history of nodule over the right parotid region. This nodule was painless and slow growing. There was no history of trauma, fever, and fatigue or weight loss. On local examination, a firm hard nodule measuring 1.5 × 1.2 cm was seen. Fine-needle aspiration cytology (FNAC) was performed using 23G needle and smears were stained and examined. On microscopic examination, the smears showed low cellularity and a single cluster of cells having round to oval nuclei with mild pleomorphism and scanty to moderate amount of cytoplasm. A repeat FNAC was advised, which showed again 1-2 clusters of similar looking cells with background showing debris [Figure 1]a and b. With these cytomorphological features and the site of lesion no conclusive diagnosis was given, however possibility of pleomorphic adenoma was rendered.
|Figure 1: (a) Fine needle aspiration smear shows clusters of tightly packed basaloid cells in background of debris. (b) Cluster of small uniform tightly packed basaloid cells (H and E, ×40)|
Click here to view
On general physical examination, all the systems were normal. All investigations including haematological and radiographic were normal. The nodule was excised and sent for histopathology examination. Grossly, the cut surface is grey-white and chalky. Microscopically, showed typical histology of pilomatricoma, comprising of nests of basaloid cells, few islands of ghost cells along with many foreign body giant cells and large areas of calcification [Figure 2]a and b.
|Figure 2: (a) Tumor is composed of islands of basaloid cells and ghost cells and specks of calcification (H and E, ×20). (b) Biphasic population composed of basaloid cells and eosinophilic ghost cells (H and E, ×40)|
Click here to view
| Discussion|| |
Pilomatricoma is a benign cutaneous appendegal tumor. It has a predilection for head and neck region and also upper extremities.  The cytological diagnosis is based on a combination of presence of basaloid cells, ghost cells and foreign body giant cells. Basaloid cells show high N: C ratio and can be seen as single cells or in clusters.  Despite these well-described features, these tumors pose a potential difficulty when diagnosed on FNAC.  Not only the diagnosis can be misinterpreted as malignancy either primary or secondary but can also be missed because of low cellularity on cytology due to less number of basaloid cells, ghost cells and areas of calcification. Wang et al.  noted that 45% of cases of pilomatricoma were incorrectly diagnosed by FNAC based on their review of multiple case reports and series. From the perspective of diagnostic cytopathology, this case teaches us two things. First, initial assessment of smears should precede correlation with the clinical picture. This means that in the relevant situation, as in our case pursuing possibilities that seem plausible from morphology alone may be rewarding. Second, it pays to thoroughly familiarize oneself with the appearance of basaloid cells and ghost cells even when there is scanty cellularity in smears.
| References|| |
|1.||Klein W, Chan E, Seykora JT. Tumors of the epidermal appendages. In: Elder DE, Elenitsas R, Johnson BL, Murphy GF, editors. Lever's Histolpathology of the Skin. 9 th ed., Ch. 30. Philadelphia: Lippincott Williams and Wilkins; 2005. p. 879-8. |
|2.||Kumaran N, Azmy A, Carachi R, Raine PA, Macfarlane JH, Howatson AG. Pilomatrixoma - Accuracy of clinical diagnosis. J Pediatr Surg 2006;41:1755-8. |
|3.||Sánchez Sánchez C, Giménez Bascuñana A, Pastor Quirante FA, Montalbán Romero MS, Campos Fernández J, Sola Pérez J, et al. Mimics of pilomatrixomas in fine-needle aspirates. Diagn Cytopathol 1996;14:75-83. |
|4.||Lozzi GP, Soyer HP, Fruehauf J, Massone C, Kerl H, Peris K. Giant pilomatricoma. Am J Dermatopathol 2007;29:286-9. |
|5.||Thapliyal N, Joshi U, Vaibhav G, Sayana A, Srivastava AK, Jha RS. Pilomatricoma mimicking small round cell tumor on fine needle aspiration cytology: A case report. Acta Cytol 2008;52:627-30. |
|6.||Ma KF, Tsui MS, Chan SK. Fine needle aspiration diagnosis of pilomatrixoma. A monomorphic population of basaloid cells with squamous differentiation not to be mistaken for carcinoma. Acta Cytol 1991;35:570-4. |
|7.||Preethi TR, Jayasree K, Abraham EK. A case of pilomatrixoma misdiagnosed as metastatic carcinoma on fine needle aspiration cytology. J Cytol 2007;24:207-8. |
|8.||Barui GN, Karmakar R, Sinha A, Bhattacharya A. Pilomatrixoma: Misdiagnosed as a round cell tumor of soft tissue on fine needle aspiration cytology. J Cytol 2009;26:125-6. |
|9.||Cigliano B, Baltogiannis N, De Marco M, Faviou E, Settimi A, Tilemis S, et al. Pilomatricoma in childhood: A retrospective study from three European paediatric centres. Eur J Pediatr 2005;164:673-7. |
|10.||Agrawal L, Kaur P, Singh J, Singh N. Pilomatrixoma misdiagnosed as round cell tumor on fine-needle aspiration cytology. Indian J Cancer 2010;47:483-5. |
|11.||Wang J, Cobb CJ, Martin SE, Venegas R, Wu N, Greaves TS. Pilomatrixoma: Clinicopathologic study of 51 cases with emphasis on cytologic features. Diagn Cytopathol 2002;27:167-72. |
[Figure 1], [Figure 2]