An Unheard Variant of Leiomyoma Cotyledonoid Dissecting Leiomyoma: Case Report

ABSTRACT

Leiomyomas are benign smooth muscle tumor of the uterus with varied morphology that are well known to undergo secondary changes. A variety of other unusual patterns of uterine leiomyoma have been described, such as parasitic leiomyoma, cellular leiomyoma, symplastic or bizarre leiomyoma, epithelioid leiomyoma, intravenous leiomyomatosis, and leiomyoma with secondary changes. Some cotyledonoid dissecting leiomyoma (CDL) appears as large fungating masses with widespread extension into the broad ligament and pelvic cavity. Due to its rarity and a clinician’s lack of familiarity, such tumors are sometimes misdiagnosed as malignancies. We present a rare case report of CDL. It is a diagnostic challenge for clinicians, pathologists, and radiologists and can be confused with malignancy due to its large size. After extensive literature research, we found 28 case reports of this variant. Little is known in the literature about this entity. We present here a case report of a 65-year-old female emphasizing its clinical, radiological, gross, and microscopic findings. A total hysterectomy was performed on the patient. This tumor does not have malignant potential, but clinicians and pathologists must be aware of its existence to avoid over-treating patients as malignancy.

INTRODUCTION

Leiomyomas are very common, benign mesenchymal tumors derived from smooth muscle cells. Most leiomyomas have a similar gross appearance and morphological pattern. Cotyledonoid dissecting leiomyoma (CDL) is a rare variant of leiomyoma, initially described by Roth et al. in 1996 with a gross and radiologic appearance concerning malignancy.[1] They are the most common uterine tumors occurring in 70% of premenopausal women[2] and more commonly occur in women of African descent.

CDL is a rare subtype of leiomyomas whose gross appearance can cause concern for malignancy. However, all the features of leiomyosarcoma such as increased mitoses, cellular atypia, and coagulative tumor necrosis, are typically absent.[1,3] Here, we describe a rare case of CDL in a female of perimenopausal age presenting with retention of urine, abdominal pain, and bleeding with anemia.

CASE REPORT

A 45-year-old female who presented to the gynecology department with a complaint of pain in the abdomen for 15 days and retention of urine for 1 month. Laboratory tests showed moderate normochromic normocytic anemia (hemoglobin 8.7 g/dL, mean corpuscular volume 80 fL, mean corpuscular hemoglobin [MCH] 25 pg, and MCH concentration 32.6 g/dL). On per vagina examination revealed a bulky uterus. Ultrasonography revealed a large adnexal mass predominately solid with increasing vascularity in the whole left side abdomen with diffuse omental thickening. A total abdominal hysterectomy with bilateral salpingo-oophorectomy was done, and the specimen was sent for histopathological examination. Grossly, the uterus with cervix with attached bilateral adnexa measuring 9 cm × 6.5 cm × 3 cm and a large mass [Figure 1] attached to the uterus measuring 43 cm × 35 cm × 10 cm. The endocervical canal measuring 2.8 cm and endometrium measuring 0.2 cm. Myometrium thickness varied from 2 to 17 cm. On serial sectioning, there were two intramural leiomyomas measuring 0.8 cm and 13 cm in diameter. The myometrium of the body of the uterus and lower uterine segment showed an irregular gray-white to gray-brown cotyledons. On cut surface, gray-white cotyledons like placenta are seen [Figure 2]. Right and left ovary measures 2.3 cm × 1.3 cm × 1 cm and 2.5 cm × 2 cm × 1 cm, respectively. The outer surface of both is smooth. On cut surface is partly solid, partly cystic, and filled with blood clot. The right and left fallopian tube measures 3.5 and 3 cm, respectively. On cut section, lumen is present. Her serum β-human chorionic gonadotropin 2.6 and cancer antigen 125 were 47.3. Microscopic examination [Figure 3] shows tumor cells arranged in variable-sized nodules as well as small clusters, cords, and singly scattered. The cells are plump, round to polygonal, and spindle with round-to-oval nuclei, vesicular chromatin, inconspicuous nucleoli, and a moderate amount of eosinophilic cytoplasm. The tumor is seen dissecting between the smooth muscle bundle of myometrium. Stroma shows marked edema, cystic changes, and areas of myxoid change and also noted are many thick-walled blood vessels. No atypia, mitosis, or necrosis was seen in the sections examined. The final diagnosis was given by dissecting cotyledonoid leiomyoma. In the present case, this variant was associated with multiple intramural leiomyoma, endometrium was proliferative, and cervix showed features of chronic ecto-endocervicitis.

Figure 1.

The gross image of cotyledonoid dissecting leiomyoma, giving a placental appearance of a large mass attached to the lateral wall

Figure 2.

Cut section with multiple tan-white nodules. Variable-sized tan-white nodules dissect the myometrium to the serosal surface and make grape-like projections on the serosal surface of the uterine fundus

Figure 3.

Microscopic images of dissecting nodules (H and E) size ×100. These nodules are composed of beningn looking spindle shaped cells without atypia,necrosis or incraesed mitosis

DISCUSSION

CDL is a rare and distinct form of leiomyoma that poses a diagnostic challenge for clinicians, radiologists, and pathologists and can be confused with malignant uterine neoplasms. Only a few cases have been reported so far in the literature.

The apex case also presented with complaints of lower abdominal pain; however, no vaginal bleeding was revealed. Tumor size was typically 2–15 cm.[4,5] Three types of CDL have been described in the literature. The first appears as an exophytic mass of multinodular tissue protruding from the lateral surface of the uterine cornua; resembling the placenta is called CDL. The second type is an intramural dissecting tumor that is confined to the uterus. These two types share similar histopathological features. The last type is pure cotyledonoid leiomyoma, which is not associated with either a parent intramural mass or intramural dissection.[6] Our case was an exophytic type.

Microscopically, it is characterized by nodules of various sizes of uniform smooth muscles arranged in interlacing and whorling fascicles. Many blood vessels were also prominent with focal hypercellular areas. However, in contrast to malignant lesions, signs of mitotic activity, nuclear atypia, cellular pleomorphism, and necrosis are absent. Vascular invasion, capsular infiltration, and metastasis are not seen. Immunohistochemistry was not performed on CDL sections as we had an experienced pathologist, and it was diagnosed on the basis of morphology and the histopathological diagnosis of CDL was given. Follow-up was done after 3 months, and the patient was doing well. In a few cases, perinodular hydropic changes may be prominent.[7]

Gurbuz et al.[8] reported a case of cotyledonoid leiomyoma that had no intrauterine portion but had extrauterine extensions. A comparative analysis of various CDL cases reported in the literature is given in Table 1. Fibroids can present with vasoconstriction too.[13,14]

Table 1.

Summary of the published cases of cotyledonoid dissecting leiomyoma

Reference	Age	Clinical presentation	Tumor size (cm) maximum dimension	Tumor location
David et al.[9]	65	Abnormal uterine bleed	15	Uterine fundus and cervix
	48	Uterine prolapse	12	Uterine fundus
Roth et al.[1]	39	Pelvic mass	10.3	Uterine cornua
	41	Abnormal uterine bleed	10	Uterine cornua
	23	Pelvic mass	25	Uterine cornua
	Unknown	Pelvic mass	24	Uterine cornua
Brand et al.[10]	24	Abdominal mass	NA	Uterine fundus
Roth and Reed[11]	46	Pelvic mass	34	Uterine cornua
Kim et al.[12]	26	Incidental	12	Posterior uterine wall
Cheuk et al.[13]	55	Abnormal uterine bleed	10	Uterine cornua
Stewart et al.[14]	58	Abdominopelvic mass	16.4	Uterine fundus
Jordan et al.[15]	46	Right adnexal mass	22	Uterine with extrauterine extension (all cases)
Saeed et al.[16]	27	Pelvic mass	41	Uterine fundus
Maimoon et al.[17]	40	Urinary retention	10	Uterine isthmus
Shelekhova et al.[18]	73	Uterine mass	8	Uterine fundus
Gurbuz et al.[19]	67	Incidental	10	Uterine cornua
Weissferdt et al.[20]	52	Abnormal uterine bleed	6.2	Uterine fundus

NA: Not available

CONCLUSION

This is one of the rare variants of leiomyoma which can mimic a malignancy. Increasing awareness is a must for clinicians and pathologists so that timely and appropriately diagnosis and management can be done. It is suggested to try to use frozen sections for better diagnosis and to preserve fertility in young women suffering from this lesion.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.